Concrete Wall Repair

Q: "How do I unplug the floor drain outside my basement door?"

Concrete Wall Repair Crack
Photo by Brian Wilder

The floor drain outside my basement door is supposed to drain rainwater to the sump pump inside the basement. However, mud is getting in through cracks in the stairwell and the drain has now plugged. How can I prevent this from happening?

—Irvine Jones, Danville, KY.


Tom Silva replies: First, clean out the crack to ­remove any debris and loose cement, then scrub off any dirt using a stiff brush and a small amount of water. If you really want to do a good job, undercut the sides of the crack slightly using a masonry chisel and a hand sledge or ball-peen hammer. Don't use a claw or mason's hammer; they can chip when striking the ­chisel and send sharp pieces of metal flying. Also, be sure to wear safety glasses when chiseling.

Next, mix up a small batch of hydraulic cement, force it into the crack, then smooth the surface with a trowel. Work quickly; hydrau­lic cement sets up fast.

That should prevent mud from coming through the wall. Now you can dig out the mud in the drain with a scoop or a spoon, whatever works. A drain auger might be able to break up any clogs farther down the pipe. In some cases, we've had to break up the concrete around drains like this to reach the clog and then pour a new floor. But hopefully you won't have to do that.


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