S
HEETW
ATERPROOFINGWhen faced with unstable substrates, crack risk, and possible high vapour pressures from inside (also in flooring subject to significant live or dead loads), one
cannot use liquid waterproofing. The alternative consists of non-base-bonded
waterproofing systems, in this documentation termed sheet waterproofing (though
such systems could also be called waterproof blankets or films).
Though base-bonded waterproofing can also be applied on to certain types of substrates, under particular conditions, such as various bituminous products [which may be liquid and be brushed on, reinforced with mineral fillers, modified with synthetic materials, contain different components, mastics, etc.], since these systems are not customarily used under modular rigid coverings, they have not been included in this documentation.
With sheet waterproofing, it is also common to find a decoupling layer beneath
the waterproofing and, in particular, to have a protecting layer on top, always
comprising a separating layer and a screed with a minimum thickness, depending on the expected stresses, in the case of flooring.
German standard DIN 18195 on waterproofing in building works, in its different
parts, constitutes a full, precise documentary reference. Part 5 (waterproofing against
water without pressure), Part 8 (waterproofing on movement joints), and Part 9
(penetrations, transitions, and terminations) are most closely linked to common modular
rigid coverings. Two other parts apply to swimming pools: Part 7 (waterproofing
against water that exerts pressure from inside) and Part 6 (waterproofing against water
that exerts pressure from outside) in buried basins and other underground installations.
Standard DIN 18195 (2000) presents a thorough classification of types of
waterproofing based on the construction element involved, type of water, water action, and place where water occurs. That classification and the waterproofing materials then allow the design and installation requirements of the waterproofing system to be drawn up. The following tables summarise those contents[1].
Classification of types of waterproofing according to standard DIN 18195 in relation to water stress or solicitation and type of floor
Nº 1 2 3 4 5 6
1 Type of
construction element
Type of water Incorporation situation Type of water action Required type of waterproofing according to 2 3 with drainage1 Damp from the floor and non-stagnant infiltration water
DIN 18195-4
4
Walls and base slab in contact with the ground above the water measurement level Capillary water Contact damp Infiltration water Very permeable floor8 > 104 m/s Less permeable floor8 ≤ 104 m/s without drainage2 Stagnant infiltration water Section 9 of DIN 18195-6:2000
5 Balconies and similar
construction elements in housing construction
Wet building areas3 in housing construction6 Water that exerts no pressure, moderate stress or solicitation Section 8.2 of DIN 18195-5:2000
6 Roof surfaces that are used5
Roofings with abundant green4 Wet building areas (excluding housing construction)6 Swimming pools7 Water that exerts no pressure, high stress or solicitation Section 8.3 DIN 18195-5:2000 7 Horizontal and sloping surfaces outdoors and in the ground; surfaces of walls and floors in wet building areas3
Rainwater Infiltration water Stagnant irrigation water4 Service water
Roof surfaces that are not used, exposed to wind and weather, without a fixed service or wear layer, including those with abundant green
DIN 18531
8 Walls, and deck slabs in contact with the ground below the water measurement level
Underground water Flood water
Every type of floor, type of building, and form of construction Water that exerts pressure from outside Section 9 of DIN 18195-6:2000 9 Construction elements that contain water, basins
Service water Outdoors, and inside buildings Water that exerts pressure from inside
DIN 18195-7
1) Drainage in accordance with standard DIN 4095
2) To foundations depths 3 m below the surface of the land, otherwise row 8
3) Definition of wet building area: internal building area with evacuation of floor water conditioned by use 4) To a stagnation height of about 10 cm with abundant green
5) For example roof decks, surfaces with abundant green, high-rise car park decks, patio cellar decks, and traffic areas subject to high stresses or solicitations by cleaning and service water, floor and wall surfaces in wet building areas, walkways or swimming pool surrounds, industrial kitchens
6) For example, balconies and similar surfaces in housing construction, floor and wall surfaces directly exposed to splashed water in wet building areas
7) Walkways or swimming pool surrounds, shower facilities 8) See standard DIN 18130-1
Bitumen sheets
Standard Designation Article Thickness Junction
overlap
Type of installation 52131 Bitumen sheet for fusion
welding with non-woven glass-fibre interlining
V 60 54 4 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52131 Bitumen sheet for fusion welding with non-woven glass-fibre interlining and aluminium
V 60 54 + AL 4 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52131 Bitumen sheet for fusion
welding with fabric interlining G 200 S4 4 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52131 Bitumen sheet for fusion welding with fabric interlining
G 200 S5 5 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52133 Bitumen-elastomer sheet for fusion welding with fabric interlining
PYE-G200 S4 4 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52133 Bitumen-elastomer sheet for fusion welding with fabric interlining
PYE-G200 S5 5 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52133 Bitumen-elastomer sheet for fusion welding with non-woven polyester-fibre interlining
PYE-PV 200 S5 5 mm 80 mm Sheets = loose installation Junctions = hot gas welding
52133 Cold-adhered elastomer sheet KSK 2–4 mm 80 mm Sheets = Primer across
the entire surface in accordance with the manufacturer’s instructions Junctions = fulled
SOURCE:[1]
Synthetic sheets
Standard Designation Article Thickness Junction
overlap
Type of installation 16729 Bitumen sheet with ethylene
copolymer E.C.B. 1.5+ 2.5+
3.0 mm
50 mm Sheets = loose installation Junctions = hot gas welding
16935 Polyisobutylene sheet P.I.B. 1.5+
2.0 mm 50 mm Sheets = loose installation Junctions = solvent welding
16937 Polyvinyl chloride – soft
compatible with bitumen PVC.–P. 1.2+ 1.5+ 2.0 mm
50 mm Sheets = loose installation Junctions = solvent welding
The standard also addresses the efficiency of the waterproofing materials in relation to their ability to close or restrict the passage of water vapour. The resistance to water vapour diffusion is expressed through the factor µ and the diffusion-equivalent air
layer thickness Sd, since µ expresses the number of times that a material is more
resistant than air at the same thickness.
Sd = µ xS Sd: Diffusion-equivalent air layer thickness, in m µ: Water vapour diffusion resistance factor
S: Waterproofing layer thickness, in m
In the case of waterproofing systems that receive screeds (as protection layers), other specialised layers and/or modular rigid coverings as finishes, the design rule is
always observed that the waterproofing Sd value must be higher than that of the
overlying covering, and be the sum of the different Sdvalues of the layers involved. The following tables provide the Sd values for the waterproofing materials and for the materials that are part of outer layers, either as protection or finish.
SdVALUES OF DIFFERENT WATERPROOFING MATERIALS
Waterproofing materials in accordance with DIN 18195 Thickness in mm
Approx. Sd
value1 in mm
(1) Bituminous waterproofing (fusion welded sheet)
4 120–250
(2) Bituminous waterproofing
(brush-on emulsions) 3 30
(3) Bituminous waterproofing Polymer bitumen emulsions (brush-on emulsions)
3 80
(4) Coarse bitumen covering modified with synthetic materials 3–5 80–125 (5) Bituminous waterproofing
(Elastomer sheet for fusion welding and cold self-adhering elastomer sheet
4 100–350
(6) Asphalt mastic 3–10 100–1500
(7) EPDM sheets 2 1000
(8) Bituminous waterproofing with metal strengthening 4 ∞
(9) Waterproofing sheets of synthetic materials – PVC 1.2 30 (10) Waterproofing sheets of synthetic materials – PVC 1.5 35
Alternative waterproofing Thickness in mm
Approx. Sd
value1 in mm
(11) Rigid waterproofing (slurries) 2–5 0.5–1.25
(12) Dispersed synthetic resin waterproofing,
Dispersed acrylate waterproofing 2–3 1.5–2.55
(13) Semi-rigid waterproofing (elastomer slurries)
2–5 1.5–3.75
(14) Synthetic resin waterproofing 2–6 100–300
1) The most unfavourable value for the construction structure is the determining value. Source: [1]
SdVALUES OF COVERINGS OVERLYING THE WATERPROOFING
Overlying coverings and auxiliary materials Thickness in mm
Approx. Sd
value1 in mm
(0)2 Adhesive + plasters 1 1.0
(1)3 Thin bed or intermediate bed 2–5 0.2–2.5
(2) Punched non-woven fabric 4–6.5 < 0.2
(3) Woven carpeting 5–8 0.2–3.0
(4) Natural cork covering 2–6 < 0.2
(5) Carpeting with compact foam/woven back 5–8 3.0
(6) Carpeting with TR back 5–7 0.2–3.0
(7)4 Installed, glazed or unglazed tiles 7–15 0.4–4.5
(8) Parquet 8–22 1–6
(9) Cork coverings, with a 0.3-mm layer 2–6 8–15
(10) Linoleum 2–4 11–20
(11) Laminate 8–11 20
(12) Cushion vinyl (CV) coverings,
(Top coverings with soft foam and waterproof mass) 1.5–4 18–50
(13) Polyolefin (PO) coverings 2–3 20–60
(14) Semi-flexible slabs (similar to mastic slabs) 1.6–3.0 32–64
(15) PVC floor coverings 2–3 50–80
(16) Rubber coverings 2–10 20–2000
(17) Synthetic resin layers 2–6 100–300
1) The most unfavourable value for the construction structure is the determining value.
2) For overlying coverings that are adhered on top, it is always necessary to add the Sd value of the adhesive and of the plaster
material to the Sd value of the covering.
3) For ceramic tiles fixed in an intermediate or thin bed, it is always necessary to add the Sd value of the intermediate or thin bed to
the Sd value of the covering.
4) See the diagram: this depends on the joint proportion. Source: [1]
In modular rigid
coverings with impervious tiles, water vapour diffuses through the tile-to-tile joints (the same also occurs with glazed ceramic tiles, whether they are impervious or not). The water vapour diffusion resistance factor is deduced from the tile-to-tile joint surface area in relation to the total tiling surface area, and from the type of grout, from the graph shown:
μ = grouting material μ joint proportion
Sdis calculated from grout thickness S (tile thickness) and from the calculated µ [Sd = µ x S].
To this, it is further necessary to add the Sd value of the adhesive or bond mortar
and, where appropriate, of the screed (floating floor screed as protection layer).
For example, in a ceramic tiling with 200x200x10 mm glazed tiles and tile installation with 3-mm-wide open joints, the proportion of the joint grid in the total surface is:
Proportion (%) = 100 200 200
203 203 100 100 97 07 3%
− ×
× × = − . ≅
If a waterproof grout [µ=15] is used, the tiling water vapour diffusion resistance factor will be about μ= 15 ≅
0 03. 500, and with a grout thickness of 10 mm, Sd = µ x S = 500 x 0.01 m = 5 m.
To this Sd it is necessary to add the adhesive Sd (Sd = about 0.5 m for a 3-mm layer), so that the waterproofing Sd will need to be larger than 5.5 m in order to observe the principle mentioned previously.
Sheet waterproofing installation
Most standards and instruction sheets contain the following recommendations and conformity requirements:
► The waterproofing shall be installed under a minimum ambient and
installation surface temperature of 5ºC
► The construction element that receives the waterproofing shall be dry, sound, well-cohered, level or with a regular slope, and also exhibit optimum flatness (without open cracks, cavities, and steps)
► In concrete floors that house installations and ducts, where waterproofing
against rising damp is planned, it is also recommendable to damp-proof the bottom of the channel before installing the pipes and the surface waterproofing [Figure 1]
► It is sufficient for the waterproofing system Sd to be >200 m in order for the waterproofing, screeds, and tiling ensemble to perform well on exposure to water vapour diffusion. The consideration of systems that are waterproof to water vapour requires Sdvalues >1500 m
► The waterproofing is assumed to be able to bridge crack formation to a
certain extent (see chart). When those bounds are exceeded, a construction solution is required that decouples the waterproofing system from the underlying substrate.
MAXIMUM ADMISSIBLE CRACKING IN SHEET WATERPROOFING
► 0.5mm wide when crack formation starts
► Maximum 2 mm wide at the end of the cracking process
► 1 mm maximum displacement of the crack edge with respect to the
waterproofing plane
► In line with the foregoing point, the principle shall be observed that the
waterproofing system cannot be assigned any transmission of forces, whatever their origin [instability of the underlying substrate, thermal oscillations, hydrostatic pressure caused by water build-up, etc.]
SOURCE:[1] Figure 2 SOURCE:[1]
Figure 1
► It is vital to place water run-off and evacuation on top of the waterproofing.
The normative references establish minimum slopes of 1% and most
construction solutions include an appropriate drainage layer for the necessary evacuation.
► The insulation layers located under the waterproofing must be compatible
with the requirements for stability and absence of stresses in the waterproofing system. In certain situations, this insulation requires installation of a barrier that closes the passage of water vapour towards the insulating layers [Figure 2].
► Not only shall the surface run-off be assured, but so shall also the evacuation of the water that runs through the drainage or condenses on the layers on top of the waterproofing, which shall be appropriately connected to the drains [Figure 3].
► The junctures with abutting construction elements, from the alignment and slight curvature (about Ø 45 mm) of the right angles, up to the ascent of the waterproofing in outdoor terraces or wet internal building areas, also need to be carefully executed2 [
Figures 4, 5]
As may be observed in the construction cross-section, both the condensation water, from the vapour migrating upwards through the deck and the slope layer, and the water filtering through the compression layer converge unhindered in the water drainage.
1. Ceramic tile 7. Soundproofing
2. Bonding material 8. Vapour barrier
3. Compression layer with reinforcement 9. Geotextile
4. Drainage (prefabricated system + geotextile) 10. Compressible material
5. Double layer of waterproofing 11. Soundproofing material
6. Thermal insulation Figure 3 SOURCE:[1] Figure 4 SOURCE:[1] Figure 5
2 The German documentation defines a
wet building area as an internal building area in which the
► The choice of waterproofing system is also made as a function of the stresses to which the system will be subjected (in the case of flooring) and of the incidence/intensity of the action of water. Every standard and technical document offers a list of materials and installation requirements, including the number of layers, thickness of each layer, overlaps between sheets, join sealing, etc. Particularly to be noted is the information provided
by the German standard DIN 18195-5 (2000) and the French standard NF
DTU 43-6 (2007) [Parts 1-1 and 1-2].
► In most construction solutions and all those that envisage drainage and a
modular rigid covering as finish, sheet waterproofing requires the
installation of a protecting layer, comprising a non-woven blanket and a
mortar screed. The first layer serves to protect/decouple the waterproofing from the mortar screed that acts as a rigid protection element and base for
the modular rigid covering. That is, a floating floor screed with the
characteristics described in the section on screeds.
Sheet waterproofing systems require installation design and skilled labour. The specification must be accurate, with careful installation, and thorough control. The repercussions of non-quality in this part are of great importance. In most cases, one needs to work with subcontractors who will assure appropriate waterproofing installation and the subsequent satisfactory performance of the waterproofing.
The informative document closes with key data, taken from the standards, on the materials involved in standard waterproofing, comprising the following sequence of layers:
1.Decoupling layer
2. Waterproofing and drainage 3. Protection layers
Decoupling layer
► Blanket of (non-woven) glued glass fibres, with a minimum surface density
of 100 g/m2 [VV 100], whose mechanical characteristics are evaluated
according to EN 29073-3:
– (Longitudinal and transverse) tensile rupture strength ≥ 300 N/5 cm – (Longitudinal and transverse) elongation in tensile rupture ≥ 1.2 %
– Tensile strength after water immersion (24 h and 50ºC) ≥ 210 N/5 cm
► Kraft paper of at least 70 g/m2
► ‘EdsF’ paper (two sheets of 60 g/m2 Kraft paper glued with 20 g/m2
Waterproofing
Those described in the initial tables. The (SBS) elastomer-modified asphalt sheets are governed by standard EN 13707
Protection
Made up of a blanket or sheet and mortar or concrete screed, with the following characteristics:
► Non-woven geotextile or synthetic material of at least 170 g/m2, which
conforms to the requirements of standard EN ISO 9864 or, alternatively, a polyethylene film at least 100 µm thick.
► Cement or concrete mortar screed proportioned in 300 to 400 kg/m3,
water/cement ratio about 0.5, chosen from common cements of resistance
class 32.5 MPa [EN 197-1]. Screed thickness never less than 50 mm, which
increases as a function of service loads and, where appropriate, of insulation compressibility and thickness.
These protection screeds on the waterproofing can be fitted with load distribution or strengthening reinforcement, whose mass shall be at least
0.250 kg/m2, electrowelded with a maximum mesh aperture of 100x100 mm.
Screeds are handed over under the flatness conditions specified by the standards.
