DIY Home Improvement Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
I am redoing my basement and I see on the cement foundation walls there is what looks like waterproofing but not sure if it’s paint or waterproofing. How can I tell what it is?

also some spots water has penetrated the walls so I would like to reinforce these areas.
If it is water proofing membrane can I apply a second coat over it?

If it’s paint I know I have to strip it all before applying thoroseal.

Thanks in advance.
 

·
Registered
Joined
·
295 Posts
I agree with Chandler. You can't solve waterproofing issues from the inside. Correct the problem on the outside with proper drain tile, tar/waterproofing on the concrete wall, sufficient height of gravel, etc. Thoroseal on the inside is a band-aid. It works best when just used to reduce humidity passing through the walls. If you're trying to stop actual water penetration from the inside with Thoroseal, it is a losing battle. The water penetration will simply move to the path of least resistance, which typically is the joint between the floor slab and the concrete block wall.
 
  • Like
Reactions: Gymschu and mark sr

·
Registered
Joined
·
5 Posts
Discussion Starter · #4 ·
Yea I know real waterproofing is done on the outside but I don’t have access to outside. I have never had any water issues in the basement before so just want the extra protection of coating the inside. There is really only two places I can see water on the inside of the foundation. Here are the pictures of the foundation.
 

Attachments

·
Registered
Joined
·
295 Posts
Like I said, nothing wrong with coating the inside, it is helpful.
Looks like you could use a wire brush and try to brush away the old paint or coating. Regardless, you need bare block before you can apply any coating, because it is a moldy mess.
But to solve the core issue and not have it recur, you need to address the issue from the outside.
First, you need a positive grade away from the house for at least 6 ft out, all the way around the house
Dig several test holes down to your footing at both outside corners of your house, at the wall that has the issues.
You will learn a lot about how the house was (or wasn't) waterproofed, and how much gravel cover they used.
Take a garden hose and flow it through the drain tile and see if it drains properly, or collects and seeps into the house.
Then correct any issue you find. You could start with having Roto Rooter snake out the drain tile if they are clogged, to see if they are salvageable without excavation and replacement.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #6 ·
i decided to install a french drain system to rectify any water issues now and in the future.

Since i am doing a french drain do i still need a vapor barrier between insulation and sheetrock?
 

·
Naildriver
Joined
·
12,173 Posts
You do unless you use Rockwool (Roxul). The paper backing on insulation acts somewhat as a vapor barrier, however.
 
1 - 7 of 7 Posts
Top