Should I Water Proof The Foundation When I Raise The Grade On My House?

A reader of my blog asked me a question the other day and I thought it was worth writing about.

The question was as follows;

"I am raising the grade on one side of my house, do I really need to extend the waterproofing up that side of the building? The grade will have good slope away from the house."

The simple answer is yes you should, you should always waterproof foundation walls below grade even though you don't think that there will be a lot of water in the ground.

Adding a waterproofing to the wall like a blueskin or something else is not that expensive and in small area's can be done by yourself or a contractor that is doing the raising of the grade. All that you have to do is the following;

• Makes sure you clean the foundation wall of any dirt, rocks or mildue. The adhesive on the back of waterproofing needs clean surfaces to stick too.
• Make sure the foundation wall is dry, better adhesion for the waterproofing.
• You can add a dimple board in front to give the waterproofing some protection from rocks and debris.

When your contractor back fills over the waterproofing makes sure there aren't any large stones or stumps that will be pushing on the foundation. This can damage the waterproofing.

The reason that you should waterproof the are isn't just to stop any kind of flooding into your foundation its also to keep all the moisture out of the foundation. When water saturates either block or concrete overtime it will start to break down the foundation, especially with freezing and thawing. This will crack and shift the foundation until it starts to crumple and then you are into a big repair bill.

A little bit of waterproofing goes a long way.

Rob Abbott
Village Builders Inc.

We Have A Crack in Our Block Foundation, Do You Think The Waterproofing Failed?

Q:

We had our foundation wall replaced, a couple of years later we now see a vertical crack near the corner of the wall do you think the waterproofing has failed?

A:

Most likely the crack is not caused by the waterproofing failing. The only way that you would end up with a crack in the wall like your describing is if the waterproofing failed, water penetrated the block cavity, the temperature dropped, the water froze and broke the block wall.

My question would be why did you have your foundation wall replaced to begin with, if the last wall failed and you had it replaced maybe the real issue was never addressed.

It’s more likely that something has shifted or moved in your foundation. Either the footing has moved underneath the block wall or the backfill is heavy and is pushing on the wall and that is causing stress cracks in the wall.

Because it is a vertical crack near the corner of the building it makes me lean toward that something has moved or shifted in your foundation, either the footing or the wall it’s self.

Before you go and have the foundation excavated or re-waterproofed or have the crack in the block repaired you should have someone investigate why the crack has occurred. This will probably require you to have the foundation dug out around the crack but there are other ways to diagnose foundation issues.

Talk to an expert, you will probably have to pay someone to find out the problem and pay more to have it fixed.

Rob Abbott
Village Builders Inc.