I just bought a new house. The basement is mostly concrete slabs, except for under the porch steps: there is a single row of cinder blocks. It's leaking water from a corner (at eye level) in that area.

They had already injected (something: foamy to touch) through the visible holes and it even came out from the porch steps outside. However, when there was a day-long heavy rain, I could still see liquid water on the wall. There was only 1 day-long heavy rain since I bought the house, so don't have much more observations. We didn't really have heavy rainfall other than that 1 day.

The contractor said that since there are hollow cinder blocks, they will always collect water, and I need to install a weeping tile. He says it's just as efficient inside and outside.

But my question is: if I install the weeping tile inside, then water is still going THROUGH my basement walls, doesn't that create the risk of water freezing and making cracks even bigger?

2 Answers 2


Controlling water infiltration after it comes through the wall is only advised if that is your only course of action. ALWAYS stop it before it comes in.

If water comes in from the outside, it will bring in silt and possibly other things may come in as well depending on how big the holes are.

The foam you added may have slowed it down, but it will not seal the hole if there is dirt on the surface or even moisture. from the water coming through.

As mentioned already, concrete is a sponge, and like a sponge, water will release if there is a large enough concentration of it. The best course of action is to apply a membrane on the outside, complete, continuous from the ground level to the footing to seal the wall to the footing. Basements usually have this, how well it is done is always a consideration. Holes in the waterproofing is the biggest issue, whether it is from a lazy installer or bumping into with hard items like shovels and such during the construction phase.

You can install a drain (weeping) tile, and there should be one already at the footing on the outside, and perhaps there is one on the inside too, under the slab. It does not matter all that much if it is there and you still have a leak. The grade or slab needs to pitch away from the house so the rain does not concentrate against the wall, The water that is left at the wall after the majority has run away from the wall can be handled by the membrane on the wall, whether it is liquid applied or a roll of material. Most are liquid applied. This membrane, along with other things like fiberboard or dimple mat as I call it, expedite the water's fall to the footing where the presumed drain tile is.


Concrete is porous. Consider it a sponge. Any water that comes in contact with it will be drawn in via capillary action.

If water is coming into your basement, it's likely because it's the easiest route for the water to take. Ideally, you'd slope/grade your yard away from the wall to get the water away from the block wall as soon as you can.

Freezing water in concrete is a concern, but that usually requires a frequent freeze/thaw cycle. Something of concern on say a driveway in cold climates, but likely won't have too much of an effect on a wall.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.