in my unfinished basement, there is white paint on the walls. how can i tell if its drylock or some type of waterproofing agent?

also, on two areas where water seems to be leaking in from the floor/wall joint, the paint about 3' above the floor is yellowish and bubbled. what does this mean? the walls have always been dry whenever i find a water issue. what do u suggest i do? thank you.

 

Drylok and block fill are the 2 most common paint materials applied to masonary walls. Since the walls are dry I would tend to think you have drylok [or similiar product] The stains you see above the wet area are probably where water is trying to penatrate. Bubbling? Are they bubbles you can pop? I would first check outside and make sure water isn't being directed to the foundation. Might be a loose downspout [or not directed away from house]. You might caulk the joint at the floor/wall but stopping the water before it gets to that point is the best solution.

 

what i meant by bubbling is the paint had bubbled up and u can peel it off. its dry paint. like i said, the walls are dry and the water comes from the floor. the outside area where the water seems to be coming in is a concrete patio slab which goes up to the foundation. there is that normal space gap the between the concrete and the foundation wall. should i put cement in there and fill it in? is it possible that it is somehow dripping down the wall in the middle of the cinderblocks and coming out the floor? i do have a high water table. i had this same issue on the otherside of my basement, but by putting a gutter and leading the downspout away from the house, i have only seen a small spot of water one time in the year since i've done this.

 

Close the potential leakage area where the slab meets the basement wall. Do not use concrete or any hard material. Water will still go through a crack.

If it is over 1/4" put in a backer rod (closed cell foam) and force it so it is about 1/4" or 3/8" below the level of the slab. Caulk with a suitable concrete and latex or polyethelene caulk (HD has this type of stuff). True to big box philosophy, you may have to hunt for the rod that is recommenced on the side of the tube they sell.

If you solved the problem by correcting a moisture condition on one side, then correcting a moisture problem on the other side should work.

If you continue have more problems. you can always apply Drylok. The "bubbles" may be from vapor pressure or efflorescence crystals forcing the coating off. If you apply any new coating, remove as much of the existing as necessary. Unfortunately, Drylok requires almost everything to be removed since it must penetrate to form a barrier and does not work as a coating (according to Drylok).

Good luck!!

Dick

 

could u try to explain the whole backer rod thing? i never heard of this so im not too sure what u r talking about.

do u have any knowledge/thoughts on that basement gutter system i have seen?

 

A backer rod is put in to fill the joint and have something to push the caulk against when you apply it. Without a backer rod, the caulk just loosely fills the gap and really does a poor job of sealing. You want the rod to be below the surface so there is a good coating of the caulk over the backer.

The new way is to use closed cell foam that is made for that purpose. Years ago, they used rope or anything that was the right size.

Dick

 

are u talking about putting this rod on the outside where the patio cement meets the foundation or down inside the basement? if in the basement, i guess i would have to make a small trench because the wall and floor seem to meet flush, with no gap.

 

I believe Dick is referring to the outside where the patio slab meets the foundation. By stopping any water infiltration you effectively dry the wall below. Backer rod is used to give the caulk more surface area to seal to [when the crack is too wide] The same caulk should work in the basement without needing backer rod. Just make sure the crack is clean. IMO drylok will work ok over paint - they just won't warrant it.

 

that's what i thought. what exactly should i look for as a backer rod? is it actually a rod like rebar? and what would the exact procedure be?

 

Picture a piece of foam rebar and that is what they are talking about, it is just a piece of solid foam that is shaped like a rod. This is foam like the pipe insulation foam and not the foam that expands when you spray it out of a can.

If you can't find that, sometimes you can use the foam insulation that builders use under the rim joist of houses. Cut it and roll it or fold it so that once you force it in the crack, it won't take a bead more than maybe 3/8" thick to fill the crack - it should tell you on the tube the max depth of a crack you can fill.