Slab-on-Grade Construction Details

In this section, typical slab-on-grade foundation details are illustrated and described. Figure 4-9 shows exterior insulation applied to a grade beam foundation. A grade beam supporting a brick veneer facade is shown in Figure 4-10 with exterior insulation. Insulation applied to the exterior of concrete and concrete masonry foundation walls is shown in Figures 4-11 and 4-12. Figure 4-13 illustrates insulation placed beneath the slab perimeter.

The inside insulation case is illustrated for masonry foundation walls in Figures 4-14

and 4-15. A foundation wall supporting a brick veneer facade is shown in Figure 4-16 with interior insulation. Numbers that occur within boxes in each drawing refer to the notes on page 75 that follow the drawings (see Figure 4-8).

The challenge at this stage of design is to develop integrated solutions that address all key considerations without significantly complicating the construction or increasing the cost. There is no one set of perfect solutions; recommended practices or details often represent compromises and trade-offs.

No particular approach is considered superior in all cases. This section shows and describes a variety of reasonable alternatives.

Individual circumstances will dictate final design choices.

OPENING IN EVERY OTHER VERTICAL JOINT

FLASHING GROUND SLOPES AWAY FROM WALL AT 5% 3

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX. 4 RIGID INSULATION 6 INSULATED BLOCK SUPPORT FOR BRICK VENEER

4-IN. GRAVEL LAYER (OPTIONAL) 14 REINFORCING (OPTIONAL) 9 CONCRETE GRADE BEAM 10 BRICK VENEER

1-IN. AIRSPACE RIGID INSULATION PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

INTERIOR FINISH MATERIAL INSULATION IN 2 x 4 WALL

4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12 VAPOR RETARDER 13

Figure 4-10: Slab-on-Grade with Brick Veneer (Exterior Insulation)

Figure 4-9: Slab-on-Grade with Integral Grade Beam (Exterior Insulation)

EXTERIOR SIDING

RIGID INSULATION USED AS SHEATHING EXTENDS DOWN TO COVER GRADE BEAM 6 PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

TERMITE SHIELD PROTECTION BOARD OR COATING 2 GROUND SLOPES AWAY FROM WALL AT 5% 3

INTERIOR FINISH MATERIAL VAPOR RETARDER INSULATON IN 2 x 4 WALL 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12 VAPOR RETARDER 13

4-IN. GRAVEL LAYER (OPTIONAL) 14 CONCRETE

GRADE BEAM 10 SILL ANCHORS AT 6 FT. O. C. MAX. 4 RIGID INSULATION MAY

EXTEND HORIZONTALLY INTO THE SOIL, SLOPING AWAY FROM SLAB EDGE REINFORCING (OPTIONAL) 9

8-IN.

MIN.

Figure 4-9 illustrates a slab-on-grade foundation with an integral grade beam. The rigid insulation is placed vertically on the exterior face of the grade beam. Additional insulation may be extended horizontally around the foundation perimeter.

Figure 4-10 illustrates a slab-on-grade foundation with an integral grade beam. This differs from Figure 4-9 in that the above grade wall is wood frame with brick veneer. The rigid insulation is placed vertically on the exterior face of the grade beam and extends upward into the cavity between the wood frame wall and the brick veneer.

Figure 4-12: Slab-on-Grade with Masonry Wall (Exterior Insulation)

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX.

EMBEDDED 15 IN. INTO FILLED CORES 5 RIGID INSULATION OVER CONCRETE MASONRY WALL 6 8 EXTERIOR SIDING SHEATHING

PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

FLASHING COVERS TOP OF INSULATION PROTECTION BOARD OR COATING 2 GROUND SLOPES AWAY FROM WALL AT 5% 3

INTERIOR FINISH MATERIAL VAPOR RETARDER INSULATION IN 2 x 4 WALL ISOLATION JOINT 11 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12

VAPOR RETARDER 13 4-IN. GRAVEL LAYER (OPTIONAL) 14 REINFORCING (OPTIONAL) 9 CONCRETE FOOTING 10 8-IN.

MIN.

Figure 4-11: Slab-on-Grade with Concrete Wall (Exterior Insulation)

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX. 4 RIGID INSULATION 6 CONCRETE FOUNDATION WALL 7 CONCRETE FOOTING 10 EXTERIOR SIDING SHEATHING

PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

PROTECTION BOARD OR COATING 2 GROUND SLOPES AWAY FROM WALL AT 5% 3

INTERIOR FINISH MATERIAL VAPOR RETARDER INSULATION IN 2 x 6 WALL ISOLATION JOINT 11 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12

2-IN. SAND LAYER (OPTIONAL) 12 VAPOR RETARDER 13 4-IN. GRAVEL LAYER (OPTIONAL) 14 REINFORCING (OPTIONAL) 9 8-IN.

MIN.

Figure 4-11 illustrates a slab-on-grade with a concrete foundation wall. Rigid insulation is placed vertically on the exterior face of the foundation wall. The 2 x 6 above-grade wood frame wall overhangs the insulation. The foundation wall is designed to permit vertical movement of the floor slab.

Figure 4-12 illustrates a slab-on-grade foundation with a concrete masonry foundation wall. Rigid insulation is placed vertically on the exterior face of the foundation wall. The top of the insulation is covered by flashing. Because the floor slab rests on the ledge of the foundation wall, it is important to compact the soil beneath the slab to minimize settlement and cracking of the slab.

Figure 4-14: Slab-on-Grade with Masonry Wall (Insulation Under Slab) Figure 4-13: Slab-on-Grade with Concrete Wall (Insulation Under Slab)

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX. 4 CONCRETE FOUNDATION WALL 7 CONCRETE FOOTING 10 EXTERIOR SIDING SHEATHING

INSULATION IN 2 x 6 WALL PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

GROUND SLOPES AWAY FROM WALL AT 5% 3

INTERIOR FINISH MATERIAL VAPOR RETARDER

RIGID INSULATION IN JOINT 11 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12 2-IN. SAND LAYER (OPTIONAL) 12

VAPOR RETARDER 13 RIGID INSULATION 15 4-IN. GRAVEL LAYER (OPTIONAL) 14 REINFORCING (OPTIONAL) 9 8-IN.

MIN.

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX.

EMBEDDED 15 IN. INTO FILLED CORES 5 EXTERIOR SIDING SHEATHING

INSULATION IN 2 x 6 WALL PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

6-IN. CONCRETE BLOCK ON 8-IN. CONCRETE MASONRY WALL 8 GROUND SLOPES AWAY FROM WALL AT 5% 3

INTERIOR FINISH MATERIAL VAPOR RETARDER RIGID INSULATION JOINT 11 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12 VAPOR RETARDER 13

RIGID INSULATION 15 4-IN. GRAVEL LAYER (OPTIONAL) 14 REINFORCING (OPTIONAL) 9 CONCRETE FOOTING 10 8-IN.

MIN.

Figure 4-13 illustrates a slab-on-grade with a concrete foundation wall. Rigid insulation is placed horizontally under the slab perimeter and vertically in the joint at the slab edge. An optional sand layer beneath the slab is shown. The foundation wall is designed to permit vertical movement of the floor slab.

Figure 4-14 illustrates a slab-on-grade with a concrete masonry foundation wall.

Rigid insulation is placed horizontally under the slab perimeter and vertically in the joint at the slab edge. In order to permit vertical movement of the floor slab, 6-inch wide concrete blocks are used in the top course. This approach utilizes a 2 x 6 above-grade wood frame wall.

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX. 4 6-IN. BLOCK SUPPORT FOR BRICK VENEER CONCRETE

FOUNDATION WALL 7

RIGID INSULATION 15 4-IN. GRAVEL LAYER (OPTIONAL) 14 REINFORCING (OPTIONAL) 9 CONCRETE FOOTING 10 BRICK VENEER

1-IN. AIRSPACE SHEATHING

PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

INTERIOR FINISH MATERIAL INSULATION IN 2 x 4 WALL RIGID INSULATION IN JOINT 11 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12 VAPOR RETARDER 13 OPENING IN EVERY OTHER

VERTICAL JOINT FLASHING GROUND SLOPES AWAY FROM WALL AT 5% 3

Figure 4-16: Slab-on-Grade with Brick Veneer (Insulation Under Slab) Figure 4-15: Slab-on-Grade with Masonry Wall (Interior Insulation)

1/2-IN. ANCHOR BOLTS AT 6 FT. O.C. MAX.

EMBEDDED 15 IN. INTO FILLED CORES 5 CONCRETE MASONRY WALL 8 EXTERIOR SIDING SHEATHING

INSULATION IN 2 x 4 WALL PRESSURE-TREATED SILL PLATE (GASKET UNDER SILL PLATE) 1

GROUND SLOPES AWAY FROM WALL AT 5% 3

INTERIOR FINISH MATERIAL VAPOR RETARDER RIGID INSULATION JOINT 11 4-IN. CONCRETE SLAB WITH OPTIONAL W.W. MESH 12 VAPOR RETARDER 13

4-IN. GRAVEL LAYER (OPTIONAL) 14 RIGID INSULATION 16

REINFORCING (OPTIONAL) 9 CONCRETE FOOTING 10 8-IN.

MIN.

Figure 4-15 illustrates a slab-on-grade foundation with a concrete masonry foundation wall. Rigid insulation is placed vertically on the interior face of the foundation wall and extends into the joint at the slab edge. Because the floor slab rests on the ledge of the foundation wall, it is important to compact the soil beneath the slab to minimize settlement and cracking of the slab. This approach utilizes a 2 x 4 above-grade wood frame wall.

Figure 4-16 illustrates a slab-on-grade with a concrete foundation wall. The approach above-grade wall system consists of a 2 x 4 wood frame wall with brick veneer. Rigid insulation is placed

horizontally under the slab perimeter and vertically in the joint at the slab edge. Because the floor slab rests on the ledge of the foundation wall, it is important the compact the soil beneath the slab to minimize settlement and cracking of the slab.

NOTES FOR ALL DETAILED