Sealing/waterproofing basement walls from inside


  #1  
Old 01-17-17, 08:43 AM
I
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
Sealing/waterproofing basement walls from inside

The corner of my poured basement concrete walls had a hairline crack that I sealed using a polyurethane injection kit. This has worked well so far but I see efflorescence buildup through on one area of the patch - indicating water leakage.
Should I remove the epoxy sealant and re-inject foam again ?

I have also noticed minor seepage on another hairline crack that I plan to fix using polyurethane

Main question : Is there anyway to ensure that this problem does not re-occur and prevent further leaks using a product (or combination of products) like

- Penetrating concrete sealers (Lithi tek 9500, radon seal etc)
Ghostshield 1 gal. Invisible Penetrating Concrete Sealer, Waterproofer Plus Densifier-9500 - The Home Depot

- Interior masonry waterproofing paints like (Drylok or Behr brands)
 
  #2  
Old 01-17-17, 08:48 AM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 48,077
Received 398 Votes on 354 Posts
Drylok does a decent job but if there is moisture migrating thru the foundation wall it will gather and look for another way out. It's always best to waterproof on the exterior side!

Do you have downspouts piped away from the foundation? does the grade fall away from the house?
 
  #3  
Old 01-17-17, 08:56 AM
I
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
I have installed extensions on every downspout and have routed them ~2-3 feet away and the grade does fall away from the house, although not by much

I agree with you on Drylok etc not being effective if there is water pushing the paint from outside.
I was wondering if these penetrating sealers really work by sealing the concrete cavities/cracks and prevent water intrusion from the outside of foundation walls (as opposed to being a water repellant/sealant like a garage or drive way application)
 
  #4  
Old 01-17-17, 09:03 AM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 48,077
Received 398 Votes on 354 Posts
They work to an extent but it will only penetrate so far. It works ok for a wall that gets damp on rare occasions but isn't a fix all. I mostly use drylok as a primer prior to painting below grade masonry walls.
 
  #5  
Old 01-17-17, 02:07 PM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,630
Received 98 Votes on 86 Posts
I think in this case the real solution is likely digging out the foundation and fixing the crack that I believe is there on the outside.
 
  #6  
Old 01-17-17, 02:17 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 27,054
Received 899 Votes on 825 Posts
Stickshift is correct. Coatings applied to the inside are known to lead to erosion of the concrete.
 
  #7  
Old 01-18-17, 02:39 PM
I
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
"Coatings applied to the inside are known to lead to erosion of the concrete."

Interesting. How so? These coating companies claim to infact harden/densify the concrete. I know this is different from the water intrusion issue

Here is an excerpt of the product description :
"An industrial-grade, water-based, proprietary sealer designed to densify, strengthen and waterproof concrete: increasing abrasion resistance while reducing moisture and vapor intrusion. Lithi-Tek 9500 is the industries most innovative product. A proprietary blend of chemistries, this clear penetrating sealer not only densifies and hardens concrete making it up to 50% stronger, but its hydrophobic nature resists moisture intrusion and vapor transmission making it the go to choice to seal basements and driveways"
 
  #8  
Old 01-18-17, 02:41 PM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 48,077
Received 398 Votes on 354 Posts
The problem lies in the moisture that is behind the coating with no place to go.
 
  #9  
Old 01-18-17, 02:52 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 27,054
Received 899 Votes on 825 Posts
Marksr is correct. Painting the inside may make it look better for a short time, but it is not solving the problem and may even speed up the deterioration of the wall. (Flaking, spalling and efflorescence.)

Here is an article that mentions the drawbacks of interior coatings.

AND a video that shows the problems associated with interior coatings.

I can't say whether or not your product would cause the same issues. But hydrostatic pressure surely has the potential to make it fail. Most products like what you describe are applied to the EXTERIOR side of a foundation to help keep the moisture out of the wall in the first place. Once the moisture is in the wall, it will want to dry to the inside, since the ground is wet it can't dry to the outside.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: