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How to seal painted basement cinder block walls that are essence

I bought a house that the basement was painted mint green (I think its regular interior paint)  The basement is damp smelling wall also have cracks. I have a dehumidifier and remove about 2-3 gallons of water daily. First can I pant over the flat painted walls. If so what do I need to do to do that. What kind of paint should I use. I know I need to repair the cracks first. (Hydrostatic patch repair )  which is the best to use 

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Posted 2017-09-19T23:59:32+0000  by House pour House pour

Howdy House pour,


Water damage and stains on drywall are usually the result of a leaky roof or plumbing fixture. Your idea of using a de-humidifier is good, it would be an even better idea to have your basement checked out by a licensed home inspector. Sometimes a damp basement can mean problem so please don’t hesitate to take this into consideration.



The next point is “what are you walls made of?” Are they cement, cinderblock, brick, drywall, lath and plaster etc? There are compounds for cement, drywall and other surfaces. Each type of wall should be addressed a bit differently.



Lastly, using a waterproofer paint is what should be used before painting to keep a moisture barrier intact. There are various types of waterproofing paint which are for different surfaces.





happy painting,

Coach Dave

Posted 2017-09-21T16:12:12+0000  by Dave_HD_OC

Hello House poor and welcome to the Community.


The most effective way to seal your basement cinder block wall is from the outside, preventing the moisture from coming in at all.  This is usually a professional type job.  You may start by getting several estimates, and learn exactly how they will approach this job.

That being said if you choose to DIY and want to apply a waterproofer to the inside you will have to start with preparation.

As with all projects, proper preparation is the MOST important step!  Before a protective treatment can be applied, any non-compatible existing sealers, paints or coatings must be removed and the surface completely cleaned and de-greased to ensure adhesion and penetration.

Since your block is painted or has an existing sealer that has failed or is incompatible with the new sealer you want to use, you will need to remove the old sealer or coating before re-sealing.

UGL latex base Drylok Masonry Waterproofer may be applied over previous coatings in sound condition but the warranty is void.  See Surface Preparation by clicking HERE.


Follow the installation instructions, which includes chiseling the crack to create a “v” groove. Use a wire brush, clean off the area around the crack, and then patch it with DRYLOK FAST PLUG, or QUIKRETE HYDRAULIC CEMENT. 


Then a good cleaning with a wire brush and their etching compound should suffice for the rest of the area. Nothing you do will remove all the paint out of the pores in the blocks, so get what you can and forget about the rest.

If you want to take a chemical approach to removing the paint, the very non-toxic product called READY-STRIP may be a good choose.


Now you are ready for the DRYLOK masonry waterproofer.


Thank you for your inquiry.



Posted 2017-09-21T16:19:48+0000  by Char_HD_CHI
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