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 Tell me about foundation waterproofing
mikey_babaganoush  [Team Member]
4/16/2012 4:03:29 PM
So i need some input on how to keep the addition dry.

The old section of house has tar, and only tar as a coating.
This seems to have worked great as there is not a single wet spot in the whole house.

So i am thinking that tar over the newer section would be a good idea as it would probably adhere to the old stuff better than a different type of coating.
Can and should i use some sort of drainage mat over the tar on the addition, or is drainage mats not suggested over tar, or is it a bad idea to use it only on part of the foundation?

Going to be a DIY job so i am hoping i can find a product i can apply cold.

Thanks in advance for the help.

blwngazkit  [Team Member]
4/16/2012 4:26:58 PM
Check with some of the supply houses near you.

Many types of foundation mastics don't require any fabrics, some do. See what is available, and the salesmen will let you know what you need to have the system function correctly.
nhsport  [Team Member]
4/16/2012 7:01:52 PM
Any coating will reduce the general dampness but if you have any amount of water sitting against the foundation it is going to fimd a way in.

The real solution is to cut off the water before it gets up against the wall with dounspouts dirrected away from the house,drains and correct gradeing of the groung around the house.

Simple in theory,dificult in practise.

A drainage mat against the wall will help ground water move directly down into a proper footing drain but isn't worth much without a free flowing gravity drain and proper material along the footings

In my area (New England) most builders have gone to sub contractors spraying the product because it is cheaper than buying the product and haveing the low man mop it on . My viewpoint is 3 or 4 years old ,with lack of building I would guess there might not be any subcontractors left
at this point

Pretty much nothing getting built around CT the last couple of years
TheRealSundance  [Team Member]
4/16/2012 9:53:36 PM
Envirosheet FTW!http://buildingmaterials.cetco.com/LeftSideNavigation/PRODUCTS/WaterproofingProducts/Envirosheet/tabid/1588/Default.aspx



TheRealSundance  [Team Member]
4/16/2012 9:59:09 PM
Tar only is called damp proofing not water proofing. If it has a membrane between layers of tar it's waterproofing. What I linked to above is what is used on commercial buildings. There's a mastic for cracks and to seal the sheets. A primer and the water proof membrane and the drainage board. A nice drainage medium with pipe is recommended. It removes water and the pressure from the water on the wall.
mikey_babaganoush  [Team Member]
4/17/2012 9:44:02 AM
Footing drains have been part of the plan from the start, the excavator is going to put them in which is why i failed to mention it before.

When the old drains were removed to excavate for the addition i inspected all the old pipes, no dirt in any of them.
The soil near me pretty much clay which could be the reason. The yard is already graded well away from the house, no concern there.

i know the drainage board may be overkill but i like to go above the bare minimum when it comes to these sort of things.