Content
FOREWORD
4
1 ADMINISTRATION OF THE CODE
5
1.1 Title 5
1.2 Scope 5
1.3 Application to build 5
1.3.1 General 5
1.3.2 Form of Application to Build 5
1.3.3 Approval in Part 7 1.4 Approvals 8 1.5 Inspections 8 1.5.1 Procedure 8 1.6 Special inspector 8 1.7 Completion certificate 9 1.8 Compliance 9
1.9 Alternate materials and types of construction 10
1.9.1 General 10
1.9.2 Standards 10
1.9.3 Application 10
2 TERMS AND DEFINITIONS
11
3 GENERAL CONSTRUCTION
12
3.1 Principle 12 3.1.1 Site preparation 12 3.1.2 Site clearance 13 3.1.3 Material storage 13 3.1.4 Batter boards 133.1.5 Driveways and paving 13
3.1.6 Earth works 14
3.1.7 Earthquake considerations 15
3.1.8 Hurricane considerations 21
3.1.9 Roofs. 30
3.1.10 Windows and doors 31
3.2 Design criteria 35
3.2.1 Conventional design 35
3.2.2 Engineered design. 37
3.2.4 Live load. 39
3.2.5 Roof load. 41
3.2.6 Lateral load design 41
3.2.7 Load factors. 44 3.2.8 Deflection. 45 3.3 Minimal requirements 46 3.3.1 Location on lot 46 3.3.2 Light 46 3.3.3 Ventilation 47
3.3.4 Minimum room areas 48
3.3.5 Ceiling height 52
3.3.6 Minimum passage 52
3.3.7 Sanitation 54
3.3.8 Toilet, bath and shower spaces 54
3.3.9 Glazing 59
3.3.10 Enclosed garages 61
3.3.11 Emergency escape and rescue openings 61
3.3.12 Exits 62 3.3.13 Landings on stairways 65 3.3.14 Pedestrian ramps 65 3.3.15 Stairways 65 3.3.16 Handrails 70 3.3.17 Guards 72 3.3.18 Foam plastic 72
3.3.19 Flame spread and smoke density 74
3.3.20 Insulation 74
3.3.21 Dwelling unit separation 74
3.3.22 Moisture vapour retarders 76
3.3.23 Protection against decay 77
3.3.24 Protection against termites 81
3.3.25 Site address 81
3.3.26 Flood resistant construction 81
3.3.27 Coastal high hazard areas. 83
3.4 Basic materials 85 3.4.1 Reinforced Concrete 85 3.4.2 Timber 90 3.4.3 Metal 90
4 FOUNDATIONS
92
4.1 General 924.1.1 Load bearing walls and columns 92
4.1.2 Reinforcement 92
5 VERTICAL STRUCTURES
98
5.1 Concrete and masonry 98
5.1.1 Masonry Block Walls 98
5.1.2 Columns, beams and shear panel structure 116
5.1.3 Framed structure See next edition to be published 119
5.2 Timber 121
5.2.1 Identification & Grade. 121
5.2.2 Exterior walls. 121
5.2.3 Interior load bearing walls. 124
5.2.4 Interior non-bearing walls. 124
5.2.6 Headers. 125 5.2.7 Cripple walls. 125 5.2.8 Wall bracing. 126 5.2.9 Structure 129 5.2.10 Cladding 129 5.3 Metal 133
5.3.1 MS beams and profiles 133
5.4 Mixed construction 133
6 FLOOR SYSTEMS
136
6.1 Concrete floor slabs 136
6.1.1 Layout 136
6.1.2 Finishing 143
6.1.3 Services 143
6.2 Timber 145
6.2.1 Identification & Grade. 145
6.2.2 General 145 6.2.3 Floor sheathing 149 6.3 Metal 150 6.3.1 MS steel beam 150
7 ROOF ASSEMBLIES
152
7.1 Roof structure 1527.1.1 Concrete roof structure 152
7.1.2 Timber 152
7.1.3 Metal 162
7.2 Roof covering 165
7.2.1 Weather protection 165
7.2.2 Materials 166
7.2.3 Requirements for material roof covering 166
8 FIGURES
175
9 TABLES
178
FOREWORD
1.In the preparation of this code, extensive use has been made of the Parts of the Caribbean Uniform Building Code (CUBIC) which deals with small buildings. The CUBIC is at this time being considered for revision and the management Committee for the revision project has elected to make use of the International Code Council Inc., of the U.S.A. in the provision of base documentation for the
revision of CUBIC. In like manner for this code use has been made of the I.C.C. year 2000.
International Residential Code Final Draft 1998.
2.The drafting of the code document has been managed by the Board of Engineering of Trinidad & Tobago, sponsored by the Joint Consultative Council in the Construction Industry and the Interim National Physical Planning Commission with the support and active participation of the Trinidad & Tobago Bureau of Standards.
3.A committee has been meeting consistently for the past two years for the preparation of this Code and comprises the following members.
The Committee, which has prepared this code, is comprised
of:-Mr. Fenrick De Four National Physical Planning Commission (Chairman)
Mr. Burnell Austin Ministry of Local Government
Mr. Stephen Basdeo National Emergency Management Authority
Mr. Kenrick Bethelmy Trinidad and Tobago Fire Services
Mr. Jack Bynoe Board of Architecture of Trinidad & Tobago
Mr. Peter Bynoe Trinidad & Tobago Institute of Architects
Dr. Richard Clarke Board of Engineering of Trinidad & Tobago
Mr. J. Holgar Hackshaw Land Settlements Agency
Mr. Adul Latiff John Donaldson Technical Institute
Dr. Jeffrey M. Phillips Board of Engineering of Trinidad & Tobago
Mr. Jean M. Picchiottino Board of Engineering of Trinidad & Tobago
Mr. Francis Pierre Sangre Grande Regional Corporation,
Ministry of Local Government
Mr. Edwin Yuk Low City Engineer, Port of Spain City Corporation
Mr. Ishmael A. Soobrattee Trinidad & Tobago Bureau of Standards (Secretary)
4.The first edition of this code [provides simple guidelines for the construction of small buildings (residential, office or light industrial) where use is made of concrete foundations, masonry block walls and timber frame roofing.
5.Future editions of this code will cover all types of small buildings constructed with concrete, masonry, timber, metal or any combination of these
1
Administration of the code
1.1 Title
These provisions shall be known as the "Trinidad and Tobago Small Buildings Code" and shall referred to herein as "This code".
1.2 Scope
1.2.1
The provisions in this code shall apply to the construction, alteration, movement, enlargement, repair, equipment, use occupancy, location, maintenance, removal and demolition of buildings, for single or multiple family residential or general purpose use of not more than two stories in height and with a floor area of three hundred square metres or less.
1.2.2
This code is intended to provide minimum requirements to safeguard life, limb, health and public welfare. It calls for minimum requirements for building materials in common use and takes into consideration the need for protection against wind and earthquake.
1.2.3
Sufficient detail is provided to allow for the adequate preparation of plans for buildings under normal environmental conditions. Regulatory authorities would deal with approvals on the basis of adherence to the requirements of this code.
1.2.4
The builder/designer is advised to seek assistance from registered professionals in the design and construction of wind and earthquake resistant structures for buildings outside the scope of this code and/or for special application or other than normal environmental conditions.
1.3 Application to build
1.3.1 General
A person wishing to erect a building or structure, or to carry out a building operation of a small building as defined shall comply with the requirements of the Planning and Development of Land Act and also with the requirements of this Code.
1.3.2 Form of Application to Build
Three (3) sets of completed application forms and plans are to be provided. The plans shall include the following:
(1)A location plan, showing the location of the lot sufficient to identify the site. Streets should be named and lots numbered where applicable.
(2)A site plan, normally at a scale of 1/100, 1/125, 1/200 or 1/250 showing the dimensions of the site and its relationship to abutting lots, roads, public utilities and buildings grades and elevations as described in (3); and the location of the proposed building in relationship to the site boundaries, which are to be identified.
(3)Existing and proposed contours and levels of the site are to be shown. The levels must show the relationship of the lowest floor of the building with the levels of the adjoining street and with the known datum.
I. Floor Plan to Metric Scale 1/50 and/or 1/100 To show:
- room sizes and designations (all dimensions finish to finish including plaster) - positioning of doors and windows
- materials used in construction
- thickness of each wall (including plaster)
II. Elevations and Sections to Metric Scale 1/50 and/or 1/100 To show:
- roof heights (floor to ceiling) and pitch - height of floor above ground
- positioning of doors and windows - materials used in construction
III. Foundation Plan to Metric Scale 1/50 and/or 1/100 To show:
- foundation layout - cross sections
- materials used in construction
IV. Structural details to Metric Scale 1/50 and/or 1/100 To show:
- details of beams - details of columns - details of slabs - details of floors - details of all walls - all reinforcement details
- roof design and construction details
V. Plumbing To show:
- water and waste isometrics - location of inspection boxes - location and details of grease traps
- sizes and slopes of the pipes used in the sewer lines - details of septic tanks and soakaway
VI. Site drainage To show:
- storm surface and roof water disposal
-All drawings shall be individually numbered for ease of reference. Revisions shall carry revision numbers.
-All drawings, specifications and accompanying data shall bear the name and address of the person responsible for the preparation of the plans and documents.
1.3.3 Approval in Part
a)Where approval of a portion of a building is desired prior to the issuance of a permit for the whole project, application shall be made for the complete buildings, and detailed plans for the which immediate approval is desired shall be filed with the Chief Building Officer.
b)Should a permit be issued for a part of a building, the holder of such permit may proceed with construction without the assurance that the permit for the entire building will be granted. The granting of such permit will depend on the approval of the application including all requirements.
1.4 Approvals
1.4.1All construction plans specifications and associated reports required by these rules should conformed to this code and shall be approved by the Chief Building Officer before construction commences.
1.4.2No construction shall commence until the Chief Building Officer has issued a permit or a written notice to proceed.
1.5 Inspections
1.5.1 Procedure
The Chief Building Officer is authorised to make the following inspections and either approve the portion of the works completed or shall notify the builder where such work does not meet with his approval:
(i) SETTING OUT
(ii) FOUNDATIONS BEFORE CONCRETING (iii) STRUCTURAL FRAME AND ROOF
(iv) RING BEAMS FORM WORK AND REINFORCEMENT (v) PLUMBING
(vi) SITE DRAINAGE
(vii) FINAL INSPECTION (OCCUPANCY CERTIFICATE)
1.5.2 All inspections shall be carried out by persons authorised as Building Inspectors or by suitably qualified persons approved by the Chief Building Officer and appointed to carry out such inspections.
1.5.3 Work shall not be done on any part of a building or structure beyond the point indicated in each successive inspection without first obtaining the written approval of the Building Inspector. Such written approval shall normally be given only after an inspection shall have been made of each successive step in the construction as indicated by each of the foregoing inspections where appropriate.
1.5.4 If circumstances warrant, the Chief Building Officer in his discretion may waive inspection but this does not absolve the owner and builder from the responsibility of any construction in contravention of this Code.
1.5.5 Reinforcing steel or structural framework of any part of any building shall not be covered or concealed in any manner whatsoever without first obtaining the approval of the Building Inspector or the Special Inspector.
1.6 Special inspector
When site conditions, size or complexity of the work warrants, the Chief Building Officer may impose a condition on the permit requiring the owner to employ a Special Inspector for the inspection of the structural framework, or any part thereof, and for the review of all plans relating to such work, as herein required.
(i) Buildings or structures or part thereof of unusual design or method of construction and with critical structural connections.
(ii) Marine construction.
(iii) Major foundations and/or pile driving. (v) Major site works.
(vi) Drainage and waste disposal.
Such Special Inspector shall be a Listed Professional with the relevant experience. The Special Inspector shall ensure compliance with this Code and shall submit regular progress reports and inspection reports to the Chief Building Officer.
At the completion of the construction work or project, the Special Inspector shall submit a Certificate of Compliance to the Chief Building Officer stating that the work was done in compliance with this Code and in accordance with the approved plan or plans. His duties shall end with the submission of such certificate.
1.7 Completion certificate
a) A new building shall not be occupied or a change made in occupancy or the nature of the use of a building or part of a building until after a Completion Certificate has been issued.
b) Upon completion of a building erected in accordance with approved plans and after final inspection herein referred to, and - upon application, the Chief Building Officer shall issue a Certificate stating the nature of the occupancy permitted.
c) A temporary Completion Certificate may be issued for a portion or portions of a building, which may safely be occupied prior to final completion of the building.
1.8 Compliance
a) The issuance and granting of a permit shall not be deemed or construed to be a permit for, or an approval of, any violation of this Code.
b) The issuance of a permit upon approval of plans and specifications, shall not prevent the Chief Building Officer from thereafter requiring the correction of errors on such plans and specifications, or from preventing building operations being carried on thereunder when in violation of this Code or any Regulations applicable thereto.
c) When during the construction of the work carried out under the permit, from issuance of permit to issuance of the Completion Certificate, the Chief Building Officer reasonably believes that approved plans are in violation of this Code, he shall notify the permit holder and the permit holder shall correct the drawings or otherwise satisfy the Chief Building Officer that the design and/or working drawings are in compliance with this Code.
d) Compliance with this Code is the responsibility of the permit holder until the issuance of a Completion Certificate; at which time it shall become the responsibility of the owner.
e) The permit granted for the construction of the work shall be available at the construction site during normal working hours for inspection by the Building Inspector.
1.9 Alternate materials and types of construction
1.9.1 General
The provisions of this Code are not intended to prevent the use of types of construction or materials or methods of designs as alternates to the standards herein set forth. Such alternates shall be offered for approval and their consideration shall be as specified in this Section.
1.9.2 Standards
The types of Construction or materials or methods of design referred to in this Code shall be con-sidered as standards of quality and strength. New types of construction or materials or methods of design shall be at least equal to these standards for the corresponding use intended.
1.9.3 Application
a) Any person desiring to use types of construction or materials or methods of design not specifically mentioned in this Code shall file with the Chief Building Officer proof in support of claims that may be made regarding the safety and sufficiency of such types of construction or materials or methods of design and request approval and permission for their use.
b) The Chief Building Officer shall approve such alternate types of construction or materials or methods of design if it is clear that the standards of this Code are at least equalled. If, in the opinion of the Chief Building Officer, the standards of this Code will not be satisfied by the requested alternate, he shall refuse approval.
3
General construction
3.1
Principle
3.1.1 Site preparation
3.1.1.1 Preliminary investigation
Before any construction work commences, it shall be determined whether planning permission and other approvals would be required from the competent (relevant) authorities. A preliminary inspection of the site shall be undertaken so that preparation may be made for any problems or diffi-culties that may arise. This time should also be used to plan how the site will be organised so that a logical layout may emerge.
3.1.1.2 Checklist for site conditions
Completion of the checklist below will provide enough information about the site and its conditions to permit construction to begin.
a) Has planning permission been obtained? b) Is easy access to the site available?
c) Is there a surveyor's or topological drawing of the site? d) Have the location of all boundary markers been found?
e) Are water, sewage disposal facilities and an electricity supply available on site?
f) Take note of the general topography of site and other physical conditions likely to cause hazards.
g) Is there evidence of termite infestation in the soil or trees? h) Will there be a need for the removal of large trees? i) Is the area normally subject to land slippage?
j) Is there adequate natural provision for the removal of storm water i.e. collection of water as a result of heavy rains or flooding.
k) Will construction endanger any of the public utility services? l) Determine the height of the water table if appropriate.
m) Determine whether the soil is suitable for the construction of a soak-away pit. n) Determine the ground floor datum.
o) Determine the depth of the foundation stratum. q) Select suitable areas for stockpiling aggregate.
r) Select an area for the location of a concrete mixer or for the hand-mixing of concrete. s) Select location of a materials storage shed.
t) Are their existing structures to be removed or altered?
Completion of the above checklist should highlight possible construction problems as well as the requirements of plant and materials. Where foundation problems are evident it is recommended that an engineer or any other appropriate professional be consulted.
3.1.2 Site clearance 3.1.2.1
Care should be taken to preserve any trees on the site. Where it is necessary to remove any trees, special care shall be taken to remove, totally, all roots and stumps of the felled trees as well as any of the other remains from the site.
NOTE There may be statutory limitations on the extent to which large trees may be removed. 3.1.2.2
The area where the building will be situated shall be stripped of topsoil. This material should be stock piled in a suitable area for later use during landscaping.
3.1.3 Material storage
3.1.3.1
Areas shall be allocated on the cleared site for the storage of materials. Coarse and fine
aggregate for the mixing of concrete and mortar shall be placed in separate heaps in a location near to the concrete mixer or concrete mixing area.
3.1.3.2
Cement, nails and finished materials (groove ply, PVC pipe, galvanised sheeting etc.) requiring protected storage shall be stored in a shed, which is weather tight and has a wooden floor raised not less than four inches off the ground.
3.1.3.3
Reinforcement steel shall be stacked off the ground to reduce corrosion.
3.1.4 Batter boards
The building shall be properly set out on the site according to the building plan. Batter boards, which are horizontal boards parallel to the sides of the building and supported by vertical boards driven into the ground shall be erected in convenient locations near the four corners of the building, and to these boards should be transferred the building lines and levels for the project.
3.1.4.1
The floor level is usually marked on the batter boards and used as a permanent reference. All wall lines and levels shall be referred to these boards. Periodic checks shall be made to ensure that these boards have not been shifted from their intended positions.
3.1.5 Driveways and paving
3.1.5.1
The driveways and paving dealt with in this section are those suitable for use as driveways and parking areas for private cars and light goods vehicles only. Driveways shall be not less than 3m wide. 3.1.5.2
The choice of flexible (asphalt) or rigid (concrete) paving is largely influenced by the soil conditions at the site and the cost of driveway. Gravel driveways and paving are acceptable if adequate drainage is available and if the gravel or crushed rock is reasonably hard, free from clay, and would not be easily crushed by the light traffic. Adequate provision for drainage shall be made.
3.1.5.3
Where firm soils or rocks are present, any type of paving previously mentioned may be used. Where soft soils are present gravel or a flexible paving is recommended.
3.1.5.4
For all kinds of paving the topsoil shall be removed and replaced by a minimum of 150 mm of compacted, granular material.
3.1.5.5
For rigid paving, a concrete slab with a minimum thickness of 100 mm is required, reinforced by
welded wire mesh of minimum 100 mm2/m wide in both directions, placed 25 mm below the slab
surface. Construction joint shall be created every 5 m. Note: A98, A142 and 150x150X4.5 BRC are acceptable. 3.1.5.6
For flexible paving a minimum thickness of 50 mm of asphalt (cold or hot mix) shall be applied and compacted by roller on an approved and adequate sub base.
3.1.6 Earth works
3.1.6.1 Site topography
3.1.6.1.1
The natural topography of the land should be maintained and any excavation or back filling that must be carried out (and deemed as necessary) should be kept to a minimum. This is necessary to maintain the natural vegetation, prevent landslides and flooding and preserve in general the natural environment.
3.1.6.1.2
It is essential therefore that buildings should be constructed in such a manner to compliment the natural topography of the site and not vice-versa.
3.1.6.2 Soil conditions
3.1.6.2.1
The characteristics of the site soil conditions shall be ascertained. If necessary, compaction shall be carried out in order to improve the bearing value of the soil.
3.1.6.2.2
Where expansive clay is encountered or where problem conditions are present, professional advice shall be sought before planning the foundation.
3.1.6.3 Excavations
3.1.6.3.1
Excavations for foundations shall be carried out along the building lines to the depth of the foundation stratum identified as suitable.
3.1.6.3.2
Excavations not exceeding 1.5 m in depth may generally be without planking and strutting, which is a system of braced timber walls erected against the faces of the excavation to prevent collapse. For excavations exceeding 1.5 m the extent of planking and strutting necessary shall be determined by the nature of the soil and the location of the water table.
3.1.6.3.3
Where collapse of the side of excavation is anticipated, all excavation in excess of 1.5 m in depth shall be planked and strutted.
3.1.6.3.4
Where the foundation is in rock, it shall be excavated at least 50 mm to provide a key for the foundations.
3.1.6.3.5
The bottom of all excavations shall be level and firm. Where loose materials are encountered, foundation bottoms shall be compacted by ramming.
3.1.6.3.6
Where excavations have been carried beyond their generally required depth, either by accident or design, the deep areas shall be back filled with compacted, adequate material or with Grade E concrete (see table B-1).
3.1.6.4 Back filling
3.1.6.4.1
Back filling shall not be carried out in dry rivers, natural drains, where water flows after heavy rains and along thalwegs (lowest areas in valleys).
3.1.6.4.2
Back filling around foundation walls and under floor slabs shall be carried out using only suitable, selected materials. Unless the floor slab is reinforced to act as a suspended slab, the depth of fill shall not exceed 1 m.
3.1.6.4.3
Suitable fill material may be brought to the site or obtained from excavated material, provided always that such material is free of substantial amounts of clay or organic matter.
3.1.6.4.4
All backfill shall be well compacted in layers not exceeding 150 mm in thickness where compaction is by hand. Where mechanical compaction equipment is used, the thickness of layers may be increased to 225 mm.
3.1.6.4.5
Where back filling under floor slabs on grade has been effected using hard core, a 50 mm layer of sand shall be applied to the top of the compacted hard core to protect damp proof membranes from puncture.
3.1.7 Earthquake considerations
3.1.7.1 Earthquake resistant construction
3.1.7.1.1 General
Trinidad and Tobago is in an earthquake zone and has experienced varying degrees of damage due to earthquakes. It is therefore essential that buildings are designed and constructed so that they have some resistance to the shaking or lateral forces produced by earthquakes.
3.1.7.1.2 Effect of soil type 3.1.7.1.2.1
The type of soil at the site may have a significant effect upon the resistance of the building to an earthquake. However for buildings within the scope of this code the effect of the soil type is not so significant provided that the building is not constructed on loose saturated sands, which may liquefy during an earthquake and cause collapse of the building.
3.1.7.1.2.2
The earthquake may also, due to shaking of the ground, compact loose sand or fill material, and if a building is constructed on such material, the building will be damaged.
3.1.7.1.3 Effect of high seas
Buildings on coastal areas may suffer due to high waves produced by earthquakes, and therefore the siting of the building in relation to the sea level needs to be considered. Professional advice shall therefore be sought in such cases.
3.1.7.1.4 Building shape
3.1.7.1.4.1
The success with which a building survives an earthquake is greatly affected by its shape in plan, the way the building is tied together and the quality of construction.
3.1.7.1.4.2
Most buildings with a simple rectangular shape with no projections (or only short projections) perform well under earthquake conditions provided the construction is adequate.
3.1.7.1.4.3
Long narrow buildings should be avoided by limiting the length to three times the width. If the building must be longer, then it should be divided into separate blocks with adequate separation. Figure A1-1 illustrates desirable and undesirable plan shapes.
3.1.7.1.4.4
Rectangular buildings with well inter-connected cross walls are inherently strong and therefore desirable.
Fig A1-1 Plan of building proportion
Separation of Blgs
to improve resistance
Long undesirable plans
Fig A1-2 Recommended location of wall opening
2 0 2 0 1 1 0 0 Floor level Floor level 1 0 0 0 400 4001 800mm min Shear panel
Fig A1-3 Recommended location of wall opening for tow storey building
Ground level
First floor
First floor
3.1.7.1.5 Appendages
Where buildings have decorative or functional additions or appendages such as window hoods, parapets and wall panels etc. extreme care must be taken to ensure that they are securely fixed, since many of such items tend to fall easily and may cause damage during an earthquake.
3.1.7.2 Rules for the construction of earthquake resistant buildings
It is recommended that the following rules be followed for the construction of buildings:
3.1.7.2.1 Masonry buildings
An important factor contributing to the earthquake resistance of masonry buildings is the detailing and placing of steel reinforcement. A registered professional should undertake the design of a reinforced concrete frame building. The reinforcing guide given in this section therefore must only be used for simple single storey buildings constructed of approved quality masonry blocks. For the minimum quantities of reinforcing steel to be used refer to Clause Vertical Structures.
3.1.7.2.2 Timber buildings
There are two additional areas of concern with respect to timber buildings: All corners and intersections must be adequately braced.
Earthquake and hurricane forces tend to remove timber buildings from their supports by shaking. Because of this sills shall be securely fastened to foundations.
3.1.7.2.3 Steel buildings
The natural ductility of steel protects the frame from severe damage. However, in many cases masonry block walls are used and the precautions already listed for these walls will apply. The wall reinforcement must now be anchored by welding to the steel columns and beams, or the steel frame encased in concrete in which case the wall reinforcement can be tied into the concrete cage encasing the steel frame.
3.1.7.3 Location of openings
3.1.7.3.1
The location and size of openings in walls have a significant effect upon the strength of a wall and its ability to resist earthquake forces.
3.1.7.3.2
Openings shall be located away from a corner by a clear distance of at least 1/4 of the height of the opening. It is recommended that the minimum distance be 400 mm.
3.1.7.3.3
The total length of the openings should not exceed 1/2 the length of the wall between consecutive cross walls (see figure A1-2).
3.1.7.3.4
The horizontal distance between two openings should not be less than 1/2 the height of the shorter opening (see figure A1-2).
3.1.7.3.5
For two storey buildings, the vertical distance from an opening to one directly above it shall not be less than 600mm, nor shall it be less than one half the width of the smaller opening.
3.1.8 Hurricane considerations
3.1.8.1 Hurricane resistant construction
3.1.8.1.1 General
3.1.8.1.1.1
It is very important in Trinidad and Tobago to be ever conscious of the fact that the region lies in the hurricane belt. Because of this, hurricane resistant construction principles must be adhered to if safe buildings are to be erected. This section gives general principles for safe hurricane resistant design, and it is recommended that the details shown in these guidelines must be adhered in order to ensure safe construction.
3.1.8.1.1.2
For the buildings within the scope of this document the areas most vulnerable to hurricane forces are the roofs, windows, walls and appendages.
3.1.8.1.1.3
The underlying objective of hurricane resistant construction is to produce a building that will not collapse during a hurricane. The building must be standing and its occupants should be safe.
3.1.8.2 Rules for the construction of hurricane resistant buildings
3.1.8.2.1 Building site
3.1.8.2.1.1
Buildings sited in exposed areas (e.g. on the brow of a hill or near coastal areas) are most vulnerable, while those sheltered by natural topography are less vulnerable. Buildings sited in gullies or riverbeds are very vulnerable as they are subject to severe damage by floods caused by the heavy rains, which often accompany a hurricane.
3.1.8.2.1.2
In siting the building, therefore, steep slopes and edge of cliffs should be avoided, as well as other conditions such as steep sided valleys where exceptionally high wind speeds are found.
3.1.8.2.1.3
Tie beams should be constructed to reduce the untied height of the columns to a maximum of 3 meters as shown in figure A1-6. It is advisable to seek professional assistance for such construction, unless otherwise designed for larger columns.
3.1.8.2.2 Timber buildings.
3.1.8.2.2.1
Because of the relatively light nature of a timber building, extra precautions shall be taken to prevent uplift. Care must therefore be taken to ensure that the entire structure is securely fastened to the foundations.
3.1.8.2.2.2
The spaces between the supporting columns or piers may be filled in to reduce the uplift forces (see figure A1-6).
3.1.8.2.2.3
As far as timber walls are concerned, in addition to bracing corners in both directions, diagonal braces or steel straps must be installed at the level of the top plate to provide rigidity of the corners at that level (see figures A1-7 and A1-8).
Fig A1-4 Typical roof gable wall arrangement
frame of building
concrete ring beam
roof reinforced
floor level
roof level
width of wall
Fig A1-5 Recommended method of construction on sloping sites
roof level
roof reinforced concrete ring beam
frame of building floor level 200mm thk. r.c. blockwall r.c. strip footing 200x300 r.c. tie beam
Ground slopes should be less than 15 degrees
existing grade 6 0 0 m m m in 9 0 0 m m m in
Steep slopes more than 15 degrees 300x300 mm min
r.c. column
r.c. footing
frame of building
200x300 r.c. tie beam concrete ring beam roof reinforced existing grade floor level roof level r.c. footing 3 0 0 0 m m m a x im u m
and less than 30 degrees
Fig A1-6 In-fill panel between timber building supports
100 X 100 Timber sill
r.c. tie beam
200mm thick blockwork
Grade
Colomn may be 200 x 200mm reinforced concrete or block work filled with concrete and 4 - 12mm rods 8mm links - 200mm centers
Fig A1-7 Timber framing showing bracing
Horizontal bracing for corners at wall plate level
50 x 100 wall plate
Uprights
25 x 150 sheating
Wall sill Brace corners by
Fig A1-8 Timber framing for wall
Wall sill Door opening Window openingWall sill is fixed to foundation wall by anchor bolts
Wall plate must be fastened and strapped to the top of uprights
The uprights are fixed to the wall sill
Double uprights at openings
Fig A1-9 Rafter/wall plate connections
Fig A1-10 Rafter/ ring beam connections
roof sheeting
roof battens
ceiling material
facia board metal hurricane tie
every other rafter
timber wall plate
r.c. ring beam 150 2 25 50 x 150 timber rafter at 600mm centers
roof eave 900mm (max)
50 x 100 timber wall plate
12mm anchor bolt at 1200mm centers (maximum) r.c. ring beam
Fig A1-11 Wall plate connections and hurricane ties
Timber rafter
Infill concrete
r.c. ring beam
metal hurricane tie imbedded in ring beam
metal hurricane tie Timber wall plate
Timber wall plate
Metal strap
Timber upright
Timber wall plate
Timber upright Mortise
3.1.8.2.3 Steel buildings
The principles for the design and construction of hurricane resistant steel buildings are: 3.1.8.2.3.1
Ensure that there are adequate numbers and sizes of foundation holding down bolts, and that they are all in place and properly fixed.
3.1.8.2.3.2
Ensure that there is adequate lateral support provided by cross bracing or horizontal ties or by cast in place concrete or masonry walls.
3.1.8.2.3.3
Where concrete walls or concrete masonry is used, the connections between the steel frames and the walls shall be provided.
3.1.8.2.3.4
Ensure that the fabricator's recommendations with regards to the construction of the roof and roof covering are followed.
3.1.9 Roofs.
3.1.9.1
Roofs with pitch between 0 and 20° (or a slope between 0 % and 36 %) are more vulnerable to uplift forces. It is recommended that roofs be constructed with a pitch between 20° and 40° (or a slope between 36 % and 84 %).
3.1.9.2
The aptitude to reduce uplift forces is affected by the shape of the roof in the following order from the most effective to the least effective:
a) Hip roof b) Gable c) Shed 3.1.9.3
Attention should be given to the location of fixings used for the roof cladding. It is necessary to provide additional fixings at the roof edges and ridge, since high-localised pressures are produced in these locations.
3.1.9.4
Roof overhangs also experience high local pressures and, where possible, these should be kept to a minimum or adequately strengthened.
3.1.9.5
Where buildings have covered patios or verandas, their roofs may be separate structures rather than extensions of the main building roof. A patio or veranda roof may be lost without endangering the safety of the main roof.
3.1.9.6
The main roof must be securely fixed to the ring beam and ridge beams and details for achieving this are shown in figures A1-9, and A1-10 and A1-11.
3.1.10 Windows and doors
Special attention must be paid to the installation of doors and windows, since the loss of a door or window during a hurricane will greatly alter the internal pressure of the building, thus adversely affecting its safety. For this reason, glazed windows and doors may be fitted with shutters.
Fig A2-1a Basic 1 or 2 level house type
Ground floor slab suspended Shear panel
Masonry
Suspended ground floor slab with crawl space
Ground floor slab suspended or on grade
Suspended first floor slab Masonry
or on grade Masonry
Ground floor slab suspended or on grade
Columns, beams & shear panel structure Framed structure or on grade
Ground floor slab suspended Columns, beams & shear panel structure
Suspended ground floor slab with crawl space
Columns, beams & shear panel structure Suspended first floor slab
Ground floor slab suspended or on grade
Suspended first floor slab Ground floor slab suspended or on grade
Suspended ground floor slab with crawl space
Framed structure Framed structure
Fig A2-1b Mixed 1 or 2 level house type
Ground floor slab suspended or slab on grade Suspended first floor slab
Ground level columns, beams & shear panel structure First level masonry
Ground floor slab suspended or slab on grade Ground level framed structure
First level masonry Suspended first floor slab
Crawl space framed structure Suspended ground floor slab Crawl space columns, beams & shear panel structure
First level masonry Suspended ground floor slab
First level masonry
Sloping site Flat site 2 levels
Fig A2-1c 1 or 2 level house, other combination
Suspended ground floor slab Crawl space framed structure First level metallic structure Ground level framed structure First level timber
Suspended first floor slab
Crawl space columns, beams & shear panel structure Ground level columns, beams & shear panel structure
First level cold formed steel Suspended ground floor slab First level timber
Suspended first floor slab
Suspended ground floor slab
One level timber Ground floor slab suspended or on grade
Shear panel with crawl space
First level timber Suspended first floor slab Ground floor slab suspended First level timber
3.2 Design criteria
3.2.1 Conventional design
Buildings and structures, and all parts thereof, shall be constructed to support safely all loads, including dead loads.
Where different construction methods and structural materials are used for various portions of a building, the applicable requirements of this part for each portion shall apply.
3.2.1.1 Conventional building
Conventional construction shall be considered as building with acceptable shape of the figures A2-1 (a to c) “1 and 2 level house type”.
All conventional construction shall be designed in accordance with this code.
3.2.1.2 Irregular building
Irregular buildings shall have an engineered lateral-force resisting system designed in accordance with accepted engineering practice.
A building shall be considered to be irregular when one or more of the following conditions occur: a) When exterior shear panels or reinforced frame is not in one plane vertically from the foundation to
the uppermost story in which they are required. (See Framed structure)
b) When a section of floor or roof is not laterally supported by shear panel or reinforced frame on all edges.
c) When an opening in a floor or roof exceeds the lesser of 3.60m or 50% of the least floors or roofs dimension.
d) When portions of a floor level are vertically offset.
e) When shear panel or reinforced frame is do not occur in two perpendicular directions.
f) When shear panel or reinforced frame are constructed of dissimilar bracing systems on any one-story level above grade.
3.2.1.3 Limit of this code.
When a building of otherwise conventional construction contains structural elements, which exceed the limits of this code, those elements shall be designed in accordance with accepted engineering practice.
3.2.2 Engineered design.
3.2.2.1 General
Buildings shall be constructed in accordance with the provisions of this code as limited by the provisions of this section.
3.2.2.2 Wind design.
The requirements in this document are based on design wind speed over open water at equivalent elevation of 10m average over 10 minutes with a recurrence of one in 50 year. (See figure A2-2 Trinidad and Tobago Winds)
Table 1 Design pressure for winds
Design pressure Trinidad
Central
Trinidad Coastal
Tobago
Basic wind speed
Km/hr 72 92 101
Wall (horizontal load) kN/m2
0.70 0.90 1.00
Roof (uplift) kN/m2 1.00 1.30 1.45
3.2.2.3 Seismic design.
All buildings shall be constructed in accordance with the provisions of this section.
3.2.2.3.1 Seismic design category.
3.2.2.3.1.1 Ground acceleration
The requirements in this document are based on maximum ground acceleration associated with 10% probability of occurrence in 50 years.
For Trinidad & Tobago 0.3 g
3.2.2.3.1.2 Amplification factor
Where the soil is 100% saturated (low land, reclaimed land, etc.) an amplification factor of 2 shall be applied to the ground acceleration. See calculation for shear load.
3.2.2.3.1.3 Soil liquefaction
To prevent any soil liquefaction on the same type of land than above a special attention shall be carried out with an engineer specialist for the choice of the appropriate type of foundation. See calculation for shear load.
3.2.2.3.2 Weights of applied finishes
Dead load finishes shall not exceed 1 kN/m2for roofs or 0.5 kN/m2for floors. Dead load finishes for walls above grade shall not exceed:
a- light-frame walls 0.75 kN/m2 for exterior 0.50 kN/m2 for interior
b- masonry walls.
2.50 kN/m2 for 150mm thick masonry wall. 3.80 kN/m2 for 200 mm thick masonry wall.
c- concrete walls.
4.10 kN/m2 for 150 mm thick concrete walls.
3.2.2.3.3 Height limitations.
The design applied to any construction is limited to two stories with a maximum of 9m to the top of the building.
3.2.2.4 Flood plain construction.
Buildings and structures constructed in flood prone areas as established in Fig. A2-1 shall be designed and constructed in accordance with Clause Flood resistant construction and Clause Coastal high hazard areas of Part "Minimal requirements".
3.2.3 Dead load.
The actual weights of materials and construction shall be used for determining dead load with consideration for the dead load of fixed service equipment.
3.2.4 Live load.
The minimum uniformly distributed live load shall be as provided in Table 2. Table 2 Minimum uniformly distributed live loads
Use Live loads (kN/m2)
Exterior balconies 5
Domestic floor / All rooms, stairs and corridors 1.5
Office floor 2.5
Small industrial and storage 5
Use Horizontal loads
(kN/m)
3.2.5 Roof load.
Roof shall be designed for the live load indicated in Table 3.
Table 3 Minimum roof live loads (kN/m2)
Tributary loaded area for any structural members
Area (m2) Roof slope
0 to 20m2 20 to 55m2 over 55m2
Flat or rise less than (20°) 33% slope
1 0.75 0.6
Rise (20°) 33% to (45°) 100% 0.75 0.7 0.6
Rise greater than (45°) 100% 0.6 0.6 0.6
3.2.6 Lateral load design
3.2.6.1 Preamble
Wind and earthquake introduce horizontal loads in the superstructure that are transferred to the foundation. We have to consider 2 steps:
a) Transfer of the horizontal load from - wind to vertical wall and roof
- acceleration of mass located everywhere in the superstructure to the appropriated wall or framed structure.
b) Transfer of the load from the top to the bottom of the wall or superstructure and the foundation. According to this code
- horizontal transfer is done by horizontal diaphragm or horizontal beam - vertical transfer is one by shear panel, cross, or framed structure
3.2.6.2 Diaphragm
Floor, roof or ceiling assemblies may be constructed with the necessary stiffness and load path continuity to distribute lateral loads (wind and earthquake) to lateral support subsystems. In this role, floor, roof or ceiling surface act as horizontal beams (also called a diaphragm) spanning lateral supports points.
Use of floor, roof or ceiling assembly, as a diaphragm requires both strength and stiffness properties and development of connections to transfer the diaphragm force.
Fig B6-1 Shear panel - Vertical core blocks
Part plan Part elevation Part elevation In situ concrete In situ concrete 400 In situ concrete ground level 1 800 4 0 0 1 0 0 0 1 6 0 0 Minimum 8002 diam. 12 every 2 rows 5 diam. 12
Shear panel
in 2 parts
Shear panel
in one part
1 5 0 m m m inFig B6-2 Shear panel - Horizontal core blocks
Part plan Part elevation In situ concrete In situ concrete ground level 1 800 1600 max 2100 min 250mm minRing beam concrete and reinforcement 500
1 1 5 200 4 dia. 12mm Part elevation ground level
Ring beam concrete and reinforcement
Part elevation ground level 150 min Limit of opening location 6mm stirrup each 150mm
Shear panel in two parts
Shear panel in one part
L1 = 1000 min L2 = 2400 mm - L1 1 5 0 m m m in
3.2.6.3 Shear panel
3.2.6.3.1 Concrete wall
A shear panel (see figures B-6-1 and B-6-2 Shear panel) is a portion or section of a 150mm exterior wall that performs the function of resisting lateral earthquake or wind forces.
3.2.6.3.2 Timber
See paragraph "Wall bracing".
3.2.7 Load factors.
All structures shall resist combined loads as follows;
3.2.7.1 Gravity 1.40 D + 1.70 L 3.2.7.2 Earthquake a) 0.75 (1.40 D + 1.70 L +/- 1.87 E) and b) 0.90 D +/- 1.43 E
3.2.7.2.1 Shear load calculation
A simplified formula, for this code is
V = 0.05 x S x W total shear in kN
Whereas :
The 0.05 coefficient integrated the Z = ground acceleration, C = amplification factor due to structure frequency, I = Importance factor =1 in this code and Rw = Ductility factor related with respect to the column design reinforcement used in the normal practice formula.
S = site factor
S = 1 For good soil (rock, gravel) S = 1.2 For softer material (clay, fill ) S = 1.5 For deep alluvial deposits
S = 2.5 maximum for reclaimed land and saturated soils (due to the amplification factor)
3.2.7.3 Wind 1.40 D + 1.70 L + 1.75 W Note: D = dead load L = live load E = earthquake load W = wind load 3.2.8 Deflection.
The allowed deflection of any structural member under the live load shall not exceed the following values in Table 4
Table 4 – Maximum deflection authorised.
Rafters and purlins L/180
Interior walls and partitions H/180
Floors and ceilings L/360
All others structural members L/240
NOTES:
3.3 Minimal requirements
3.3.1 Location on lot
3.3.1.1 Exterior walls.
Exterior walls with a fire separation distance less than 1.25m shall have not less than a one-hour fire-resistive rating. The one-hour fire resistive rating of exterior walls with a fire separation distance less than 1.25m shall be rated for interior and exterior exposure. Projections beyond the exterior wall shall not extend more than 300mm into the fire separation distance. Projections extending into the fire separation distance shall have not less than one-hour fire-resistive construction on the underside. The above provisions shall not apply to walls, which are perpendicular to the line used to determine the fire separation distance.
3.3.1.2 Openings.
Openings shall not be permitted in the exterior wall of a dwelling with a fire separation distance less than 1.25m. This distance shall be measured perpendicular to the vertical plane of the opening.
3.3.2 Light
3.3.2.1 Habitable rooms.
All habitable rooms shall be provided with an area to allow natural light to enter not less than 10 percent of the floor area of such rooms.
3.3.2.2 Adjoining rooms.
For purpose of determining requirements of light, any room shall be considered as a portion of an adjoining room when at least one-half of the area of the common wall is open and unobstructed and provides an opening of not less than 10% of the floor area of the interior room but not less than 2.50m2.
3.3.2.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with an area to allow natural light to enter not less than 0.25m2.
3.3.2.4 Stairway illumination.
All interior and exterior stairways shall be provided with a means to illuminate the stairs, including the landings and treads.
Interior stairs shall be provided with an artificial light source located in the immediate vicinity of each landing at the top and bottom of the stairs.
Exterior stairs shall be provided with an artificial light source located in the immediate vicinity of the top landing of the stairs.
3.3.3 Ventilation
3.3.3.1 Natural ventilation
3.3.3.1.1 Habitable rooms.
Natural ventilation shall be provided in all habitable room through windows, louvres or other natural openings through the external wall to the outdoor air.
The minimum area of ventilation shall be not less than 15 percent of the floor area of such rooms.
3.3.3.1.2 Adjoining rooms.
For purpose of determining ventilation requirements, any room shall be considered as a portion of an adjoining room when at least one-half of the area of the common wall is open and unobstructed and provides an opening of not less than 15% of the floor area of the interior room but not less than 2.50m2.
3.3.3.1.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with a ventilation area not less than 0.25m2.
3.3.3.2 Mechanical ventilation
3.3.3.2.1 Habitable rooms.
All habitable rooms shall be provided with the minimum ventilation rates of 30m3/hr for continuous ventilation for every 12m2of the floor area or part of such rooms.
This ventilation shall be through windows, doors or other natural openings through the external wall from the outdoor air through a special 30m3/hr-air regulator.
3.3.3.2.2 Kitchen and bathrooms
All the air introduced into the house through the habitable rooms must be extracted in the rooms e.g. kitchen, bathroom, toilet, washing room and other similar rooms have to be maintained in depression to create an air flow through the house.
The minimum exhaust airflow for each room is as follows
Kitchen 120 m3/hr
Bathroom 60 m3/hr
Shower 60 m3/hr
Toilet (WC) 30 m3/hr
Washing room and store room 30 m3/hr
This ventilation air shall be exhausted permanently and directly outside.
3.3.3.2.3 Internal doors
All internal doors have to be provided with air passages not less than 150 cm2.
Note: These passages can be provided with a bottom gap of 2 or 2.5cm under the door.
3.3.3.2.4 Minimum global ventilation
For each house or apartment the minimum ventilation rate is one volume of the habitable part of the house per hour.
3.3.4 Minimum room areas
3.3.4.1 Minimum area.
Every dwelling unit shall have at least one habitable room (living, sleeping, eating or cooking room), which shall be not less than 12m2of floor area.
3.3.4.2 Other rooms.
Other habitable rooms shall have a gross area of not less than 7.50m2.
3.3.4.3 Exception:
Kitchen not less than 5m2
Bathroom not less than 3m2and not less than 2m2 for the second one
Shower not less than 1.5m2
Toilet (WC) not less than 1m2
See figure A3-1 Minimum room sizes, A3-2 Typical furniture arrangement and A3-3 Typical
Fig A3-1 Minimum room sizes
2500mm minimum 3000mm 3464mm square 4800mm 4000mm 3464mm 3000mm 2500mm minimum 2739mm square 2739mm 1800mm min 2778mm 2143mm 1400mm min 900mm min 750mm min 1667mm 1333mm 1732mm square 1732mm 2236mm 2236mmMain room
12m2 min
Other room
7.5m2 min
Kitchen
5m2 min
Bath.
3m2 min
Shower
1.5m2 min
WC
1m2 min
800mm 1250mm minFig A3-2 Typical furniture arrangement
1333mm1m2 min
12m2 min
Main room
4000mmWC
2143mm 1800mm min5m2 min
Kitchen
2778mm 1667mm 750mm min1.5m2 min
Shower
900mm mini 1400mm minBathroom
3m2 min
3000mm 890mm 785mm 685mm 685mm 685mmEntrance
Fig A3-3 Typical furniture arrangement - 7.5 m
2room
2500mm minimum 3000mmOther room
7.5m2 min
2500mm minimum 3000mm3.3.4.4 Minimum dimensions.
Habitable rooms shall not be less than 2.50m in any horizontal dimension.
Exception: minimum
Kitchen 1.80m wide.
Bathroom 1.40m wide.
Shower 0.90m wide.
Toilet (WC) 0.75m wide and 1.25m long.
Corridor 1.00m wide.
Stair 1.00m wide.
3.3.4.5 Height effect on room area.
Portions of a room with a sloping ceiling measuring less than 1.50m or a furred ceiling measuring less than 2.15m from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required habitable area for that room.
3.3.5 Ceiling height
3.3.5.1 Minimum height.
3.3.5.1.1 Habitable rooms
Habitable rooms (living, sleeping, eating or cooking room) and basement shall have a ceiling height of not less than 2.40m. See figures A3-4 Habitable room area
3.3.5.1.2 Other rooms
Other rooms e.g. corridors, bathrooms, toilet rooms and laundry shall have a ceiling height of not less than 2.15m.
3.3.5.1.3 Measurement
The required height shall be measured from the finish floor to the lowest projection from the ceiling.
3.3.6 Minimum passage
The minimum passage for the access to the dwelling and each room shall be as follows
3.3.6.1 Main entrance
Almost one access door from outside shall be not less than 900mm wide and 2000mm high.
3.3.6.2 Habitable rooms and secondary rooms e.g. Store and laundry
All passage for the access from another room or from the corridor shall be not less than 785mm wide and 2000mm high
3.3.6.3 Other rooms e.g. Bathroom and toilet
All passage for the access from another room or from the corridor shall be not less than 685mm wide and 2000mm high
Fig A3-4 Habitable room area
2400mm1500mm minimum Habitable area
2.40m area
Room total area
2150mm lowest habitable part
3.3.7 Sanitation
3.3.7.1 Toilet facilities.
Every dwelling unit shall be provided with a water closet or privy, lavatory basin, and a bathtub or shower.
3.3.7.2 Kitchen.
Each dwelling unit shall be provided with a kitchen area and every kitchen area shall be provided with a sink.
3.3.7.3 Sewage disposal.
All plumbing fixtures shall be connected to a sanitary sewer or to an approved private sewage disposal system.
3.3.7.3.1 Septic tank
The capacity of the septic tank shall be calculated on the basis of 500 litres of sewage per person, full time user.
The minimum capacity is 2,500 litres
The water table must be a minimum of 1 metre deepest than the septic tank. See figure A3-11 for 2500 litres and A3-12 for 3200 litres septic tank.
See also "Code of Practice for the Design and Construction of Septic Tanks and Associated Secondary Treatment and Disposal System" TTS 16 80 400: 1986.
Note: The above figures complied with this code.
3.3.7.3.2 Soak-away pit
See figure A3-13
The water table must be a minimum of 1 metre deepest than the soak-away.
3.3.7.3.3 Draining trench
Where is impossible to make a soak-away, a draining trench shall be used See figure A3-14
3.3.7.4 Water supply to fixtures.
All plumbing fixtures shall be connected to an approved water supply.
Kitchen sinks, lavatory basins, bathtubs, showers, bidets, laundry tubs and washing machine outlets shall be connected to the water supply system.
3.3.8 Toilet, bath and shower spaces
3.3.8.1 Space required.
Fixtures shall be spaced as per Figure A3-5 Toilet, bath and shower spaces required.
3.3.8.2 Bathtub and shower spaces.
Bathtub and shower floors and walls shall be finished with a smooth, hard and non-absorbent surface. Such wall surfaces shall extend to a height of not less than 1.80m above the floor.
Fig A3-5 Toilet, bath and shower space required
min 50mm Clearance min 600mmLavatories
Shower
Tub
Tub
Tub
Water closet
or bidet
Wall
min 375mm min 300mm Clearance in front of 900mm min min 900mm clearance mini. 600mm min 100mm opening 600mm min min 100mm min 100mmFig A3-11 Septic tank 2500 litres - 5 persons maxi
Ventilation pipe 100mm Cleanout 100mm Sewage inlet slope 2.5% (1 in 40) dia 12mm every 200mm dia 12mm every 200mm both directions 8 dia 10mm 6 dia 10mm 7 5 590 10 0 1210 900 2 1 5 0 1 5 0 100 2059 2365 9 0 0 4 5 ° 408 9 0 0 1 2 1 0 9 0 04 dia 12x 2400mm every 2 rows
All concrete blocks filled with concrete
16
0
0
inside waterproof liner
500 1462 1 1 9 2 4 0 0 Outlet Tie beam
and tie beam
or boundary min 1500mm/building m in 1 5 0 0 m m Inspection dia 300mm
Fig A3-12 Septic tank 3200 litres - 8 persons maxi
16 0 0 40 8 45 ° 9 00 1 5 0 21 5 0All concrete blocks filled with concrete 100
and tie beam
4 dia 12x 2500mm every 2 rows both directions dia 12mm every 200mm Tie beam Outlet 1 0 0
inside waterproof liner dia 12mm every 200mm slope 2.5% (1 in 40) Sewage inlet 9 0 0 11 9 2 550 1657 75 40 0 8 dia 12mm 6 dia 12mm Cleanout 100mm Ventilation pipe 100mm 1072 1376 2295 2600 1 3 7 6 1 0 7 2 550 950 950 652 Inspection dia 300mm m in 15 0 0 m m min 1500mm/building or boundary
FIG A3-13 Soak-away
FIG A3-14 Draining trench
Inlet
Natural sand vein
25mm stone
50mm flat silica stone dia. 1400mm 1700 square 1100 (porous layer) min 1000mm/boundary min 2500mm /building
Top soil and vegetation
Inlet
Top soil and vegetation Perforated 100mm pipe
1 2 0 0 1 5 0 4 0 0 6 5 0 10 metres minimum Natural sand vein
25mm stone
general slope 2% (1 in 50)
500
3.3.9 Glazing
3.3.9.1 Identification.
Each pane of glazing installed in hazardous locations shall be provided with a manufacturers or installers label, designating the type and thickness of glass and the safety glazing standard with which it complies, which is visible in the final installation. The label shall be acid etched, sandblasted, ceramic-fired, embossed mark, or shall be of a type, which once applied cannot be removed without being destroyed.
3.3.9.1.1 Identification of multipane assemblies.
Multipane assemblies having individual panes not exceeding 0.10m2in exposed area shall have at least one pane in the assembly identified. All other panes in the assembly shall be labelled.
3.3.9.2 Louvered windows or jalousies.
Regular, float, wired or patterned glass in jalousies and louvered windows shall be no thinner than nominal 4.80mm and no longer than 1.20m. Exposed glass edges shall be smooth.
3.3.9.2.1 Wired glass prohibited.
Wired glass with wire exposed on longitudinal edges shall not be used in jalousies or louvered windows.
3.3.9.3 Human impact loads.
Individual glazed areas including glass mirrors in hazardous locations such as those indicated shall pass the test requirements of CPSC 16-CFR, Part 1201.
3.3.9.4 Hazardous locations.
The following shall be considered specific hazardous locations for the purposes of glazing: 1.Glazing in ingress and means of egress doors except jalousies.
2.Glazing in fixed and sliding panels of sliding (patio) door assemblies and panels in doors including walk-in closets.
3.Glazing in storm doors.
4.Glazing in all unframed swinging doors.
5.Glazing in doors and enclosures for hot tubs, whirlpools, saunas, steam rooms, bathtubs and showers. Glazing in any part of a building wall enclosing these compartments where the bottom exposed edge of the glazing is less than 1.50m measured vertically above any standing or walking surface.
6.Glazing, in an individual fixed or operable panel adjacent to a door where the nearest vertical edge is within a 600mm arc of the door in a closed position and whose bottom edge is less than 1.50m above the floor or walking surface.
7.Glazing in an individual fixed or operable panel, other than those locations described in Items 5 and 6 above, that meets all of the following conditions:
7.1 Exposed area of an individual pane greater than 0.80m2. 7.2 Bottom edge less than 450mm above the floor.
7.3 Top edge greater than 900mm above the floor.
7.4 One or more walking surfaces within 900mm horizontally of the glazing.
8. All glazing in railings regardless of an area or height above a walking surface. Included are structural baluster panels and non-structural in-fill panels.
9. Glazing in walls and fences enclosing indoor and outdoor swimming pools where the bottom edge of the poolside is (1) less than 1.50m above a walking surface and (2) within 1.50m horizontally of the water’s edge. This shall apply to single glazing and all panes in multiple glazing.
3.3.9.5 Wind and dead loads on glass.
3.3.9.5.1 Vertical glass.
All glass sloped 15 degrees or less from vertical in windows, window walls, doors and other exterior applications shall be designed to resist the wind loads specified in Clause 2.3 Design criteria Table 1 Design pressure for winds. Glazing designed in accordance with these provisions shall be firmly supported on all four edges.
3.3.9.5.2 Sloped glazing.
All glass sloped more than 15 degrees from vertical in skylights, sunspaces, sloped roofs and other exterior applications shall be designed to resist the most critical combinations of loads.
3.3.9.5.3 Thicker glass.
Allowable loads for glass thicker than 6.4 mm shall be determined in accordance with ASTM E
1300.
3.3.9.6 Skylights and sloped glazing.
3.3.9.6.1 Definition.
Any installation of glass or other transparent or translucent glazing material installed at a slope of 15 degrees or more from vertical. Glazing materials in skylights, solariums, sunspaces, roofs and sloped walls are included in this definition.
3.3.9.6.2 Permitted materials.
The following types of glazing may be used:
1. Laminated glass with a minimum 0.40mm poly-vinyl-butyral interlayer for glass panes 1.50m2 or less in area located such that the highest point of the glass is not more than 3.60m above a walking surface or other accessible area; for higher or larger sizes, the minimum interlayer thickness shall be 0.80mm.
2. Fully tempered glass. 3. Heat-strengthened glass. 4. Wired glass.
5. Approved rigid plastics.
3.3.9.6.3 Screens general.
For fully tempered or heat-strengthened glass, a retaining screen shall be installed below the glass, except for fully tempered glass.
3.3.9.6.4 Screens with multiple glazing.
When the inboard pane is fully tempered, heat-strengthened, or wired glass, a retaining screen shall be installed below the glass.
3.3.9.6.5 Screens not required.
Screens shall not be required when fully tempered glass is used as single glazing or the bottom pane in multiple glazing and either of the following conditions is met: