Tempo:
Floor-Wall Intersections
Control Joints
A good seal is necessary between foundation walls and floor slabs to prevent radon gas from entering the basement (Figure 41). The polyethylene moisture barrier underneath the slab should extend at least 100 mm (4 in.) up the inside of the foundation walls and be sealed to the foundation.
Cracking in concrete slabs and walls can be minimized by using steel reinforcing rods or control joints (Figure 42) formed by nailing bevelled wood strips to the inside of both interior and exterior wall forms. Their purpose is to create a weakness in the wall that will predetermine the location of shrinkage cracks.
41 Typical floor slab/wall isolation joint polyethylene sheet joint filler
42 Control joint in basement wall caulk outside face of wall at joint
12 mm (1⁄2 in.)
control crack 19 mm (3⁄4 in.) 19 mm (3⁄4 in.) bevelled 19 mm (3⁄4 in.) strip nailed to inside and outside form face to make grooves
Note: The combined thickness of inner and outer strips should equal approximately one-fifth of the wall thickness. This example is for an 200 mm (8 in.) thick foundation wall.
Control Joints
A good seal is necessary between foundation walls and floor slabs to prevent radon gas from entering the basement (Figure 41). The polyethylene moisture barrier underneath the slab should extend at least 100 mm (4 in.) up the inside of the foundation walls and be sealed to the foundation.
Cracking in concrete slabs and walls can be minimized by using steel reinforcing rods or control joints (Figure 42) formed by nailing bevelled wood strips to the inside of both interior and exterior wall forms. Their purpose is to create a weakness in the wall that will predetermine the location of shrinkage cracks.
41 Typical floor slab/wall isolation joint polyethylene sheet joint filler
42 Control joint in basement wall caulk outside face of wall at joint
12 mm (1⁄2 in.)
control crack 19 mm (3⁄4 in.) 19 mm (3⁄4 in.) bevelled 19 mm (3⁄4 in.) strip nailed to inside and outside form face to make grooves
Note: The combined thickness of inner and outer strips should equal approximately one-fifth of the wall thickness. This example is for an 200 mm (8 in.) thick foundation wall.
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