CONCRETE SLAB SUBFLOORS
Ensure the cement (concrete) slab in the shower pan area is level. Use SLU as needed, in order to level the shower pan area.
Begin by breaking the concrete around the waste pipe to produce a hole that is roughly 5 1/2-in to 6 1/2-in in diameter, around the waste pip. The hole should be centered with the waste pipe. Use a tape measure to ensure the hole size is within this range, measuring in several locations.
Using a speed square and tape measure, continue to dig out the depth of the hole around the pipe. The recommended depth is 3-in while the recommended diameter is 5 1/2-in to 6 1/2-in.
Continue breaking the concrete around the pipe and remove debris as needed with a shop vac. The hole is complete when 3-in depth is achieved at the required hole diameter range.
Using a speed square and permanent marker, mark the exact slab height onto the pipe. Using a hack saw or other means, cut the PVC waste pipe above the subfloor elevation mark you made with the permanent marker. To prevent debris from entering the waste pipe, stuff a cloth inside and below the cutting area. Once the cut is complete, vacuum out the debris and remove the cloth.
Using an inside hole saw and tape measure, carefully mark waste pipe exactly 1 5/8-in below the slab elevation. Cut through the pipe slowly to produce a level cut around the perimeter. Using a file, debur the pipe and clean out all of the remaining debris around and inside the waste pipe.
Without adhesive, place the GoBoard Point Drain onto the waste pipe ensuring the square clamping collar rests on the concrete slab and the waste pipe is securely inserted into the drain body. Using a tape measure, properly align the square clamping collar so the edges are parallel with the adjacent walls. Once the drain is positioned properly, mark the proper location by tracing a square around the camping collar with a permanent marker.
Using a margin trowel, apply modified thin-set mortar around the perimeter of the hole leaving enough space for application of the PVC cement (or ABS). Apply modified thin-set mortar to the drain body such that the mortar approximates the volume of the hole around the waste pipe. Use excess mortar so that it will squeeze out as the drain is installed. Modified thin-set mortar with peanut butter consistency works best to prevent sag. Make sure the waste pipe and drain body bonding surfaces are clean.
With all bonding surfaces cleaned, apply PVS (or ABS) cement on the outside surface of the waste pipe and then on the inside bonding surface of the drain body, following the manufacturer's instructions.
Carefully align the drain body with the waste pipe and slowly push the drain body onto the waste pipe. As the drain body is slowly pushed down onto the waste pipe, excess thin-set mortar will begin to squeeze out. At the same time, rotate the drain body such that it is positioned squarely within the square permanent marker outline. Continue pushing the drain body down until the square clamping collar firmly rests on the concrete slab. Remove all excess thin-set mortar from around the perimeter of the drain body.
Unfold the integrated waterproofing membrane to look inside the drain body and double check that the waste pipe is securely inserted inside, such that the pipe is near the fins.
Make sure the waste pipe cannot be pushed downward during the GoBoard Point Drain assembly installation. There are numerous methods to secure the waste pipe, but the simpest method is to place blocking underneath the drain pipe to achieve the correct distance from the subfloor.