Can you explain the difference between waterproofing on a roof and the waterproofing on a foundation?

Q:

Can you explain the difference between waterproofing on a roof and the waterproofing on a foundation?

A:

There are many different types of waterproofing out there, but I believe what you are asking is what is the difference between a product like Grace Ice and Water Shield (which is installed on top of your roof as a waterproofing layer under your shingles) and a product like BlueSkin VP 200 which is made to be installed on a foundation as a waterproofing.

It’s a good question, both products look a lot a like, they are installed in the same way and are both trying to achieve the same goal, which is to stop water from entering your home. They are both installed by removing the protective back paper which exposes the adhesive, then the product is stuck to the surface that you wish to protect and smoothed out. The self-adhering material on the backside does not require anything else to help it hold on to the surface that it has been applied too.

The differences come when you look at what they have been manufactured to do.

I will start with the Grace Ice and Water Shield, that product is made to protect your roof;

This product is manufactured so that it is soft and pliable. Once it’s installed on a roof shingles are installed over top of the material, as the shingles are installed with nails the product bends and coats the nail as it penetrates through the product. This helps stop any water from running down the nail into the building. The surface of this product is also made with some grip so that the installer doesn’t feel like they are walking on a skating rink. The product is not engineered to be left exposed to the elements for a prolonged period of time; it is engineered to have another material installed over top of it to protect it from the natural elements.

BlueSkin VP 200 which primarily is made too waterproof foundations is installed the same way as Grace but is made to be installed on a vertical surface. The product has a more rugged exterior layer that holds up to exterior pressures and impacts. BlueSkin will not coat a nail like Grave when it penetrates through the surface of it.
The outside layer is also made to be extremely slick. It is not advised to walk on it if it’s placed on a surface because it will be a safety hazard. The reason that the outside layer is like this is because it helps shed water, rocks and roots that might come to rest against it when underground. BlueSkin will survive underground without anything to protect it but it is still recommended that a dimple board be installed over it just encase a large rock impacts the foundation.

If you are thinking about using a foundation waterproofing on your roof or vice versa to save money because one product is cheaper than the other I caution you, by doing this you are taking a large risk. These products have been engineered for the purpose that is stated on the package and you will be voiding any warranty that comes with them by applying them somewhere else.

Thanks for the question

Rob Abbott
Operations Manager
Village Builders Inc.