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Last Updated: , Created: Tuesday, September 14th, 1999

Getting a poorly constructed concrete veranda to work

Lisa in Markham Ontario has a real water problem because her contractor did not follow the architect's plan for the construction of a concrete veranda around most of her house. The architect had planned a membrane below the concrete as well as a curb between the deck and the house wall. None of that was done, not to mention a bad slope, and in addition the concrete was poorly mixed and began to crack. So water come right into the house. Dealing with the contractor is one question. Getting the veranda to work is another.

Where the concrete curb should have a permanent barrier against surface water reaching the wall, the contractor put a little decorative flashing and some caulking. That means that Lisa will have to check and maintain the caulking every year as unfortunately the caulking is her primary line of defense, rather than just a backup to good flow-off design. I would recommend PL Polyurethane caulking as it sticks very well to concrete and stays flexible for many years. Put on properly, and if there is not too much movement she might not have to do much but check it for a long time.

The cracks in the deck will have to be patched, and if she is worried that it might move some more she should use the flexible polyurethane sealant again. But if it has stopped cracking she could fill it with concrete patching, like Top'n Bond.

Then to remove some of the standing water from the efforts to seal the cracks, I would recommend using a masonry blade in a circular saw and cutting a little irrigation ditch about 2 inches from the wall -- about 1/4 in deep by 1/4 in wide, all along the veranda. This should help to run off most of the water that flows towards the house and will look almost like a decoration. The only problem here is she will have to keep it swept clean.

Those are all patches and not nearly as good as following a good design in the first place. The sorry thing about Lisa's problem is that she did have an excellent plan, but the contractor just didn't follow it.


Keywords: Porch, Veranda, Concrete, Leaking

Article 265