Sealer recommendations for cinder block walls

[Handyalexander]

Gentlemen,

We will be remodeling a basement in a house with a hollow cinder block foundation. The basement has no water issues, but the wall sections that are underground have deteriorated to some extent. The homeowner wishes to have the walls sealed to keep out any moisture, and we do not wish to trap moisture between the walls and the vapor barrier.

The deterioration looks almost like foam on top of a beer in a lot of places and crushes into a fine powder in your hand.

Any recommendations as to what product would be best to seal this foundation? We used to use a product made by Porter years ago on bricks but I don't know if Porter Paints even exist anymore.

Any thoughts are appreciated, thanks.

( I also posted this in drywall and finishes, so we'll see how that goes. )

[[email protected]]

Re: Sealer recommendations for cinder block walls

It's been a long time since I messed with concrete blocks but there used to be a product that was new about 38 years ago called "block bond". It was used to coat dry stacked blocks, and had chopped fiberglass in it. Here's a link to something that sounds like the same stuff.

http://www.thenaturalhome.com/drystackblock.htm

If they say this stuff will work, I would in turn coat it with thoroseal mixed with acryl 60 on the outside.

You do realize that this is the interior trim forum don't you?

Good luck.
jimc

[always-learning]

Re: Sealer recommendations for cinder block walls

Handy,

You say that you don't have any water issues.

You may wish to re-think that because your description "The deterioration looks almost like foam on top of a beer in a lot of places and crushes into a fine powder in your hand."

Cinder Block or CMU's do not naturally deteriorate unless there is water or moisture infiltrating somewhere. Before you apply any type of coating you may want to unearth the exterior of the home directly opposite this deterioration that you speak of to see what's happening in the earth exposed areas of the block. If there's damage on the interior, what is happening below grade?

[Bill Robinson]

Re: Sealer recommendations for cinder block walls

That foam sounds like efflorescence to me.

"salt deposits left behind by water"

Bill R

[Handyalexander]

Re: Sealer recommendations for cinder block walls

Yes, I know this is the interior trim forum, I am here a lot, just a question for the experts that have been around a long time. Who would you expect me to ask this of? Framers? Please........... Before we do the trim, we make walls and before we do that we insulate, do a vapor barrier, etc. Some of us don't have the luxury of just cutting crown all day.

As far as digging up around the house, that isn't an option here, ideally the house would be waterproofed from the outside, and the blocks would be filled in not left hollow. I need to deal in reality here.

Thanks for the word efflorescense, all I could think of was spalling, and that is something different than this

I appreciate all the help.

[dgbldr]

Re: Sealer recommendations for cinder block walls

Who would you expect me to ask this of? Framers?

No, actually this belongs in Building Science. I don't mind you posting it here, but no need to snap at Jim. He was correct.

Yes, you do need to deal in reality here. And the reality, as Chuck suggested, is that there IS a water issue if you can see efflorescence inside, and there is no such thing as sealing hollow block from the basement side. If you paint a sealer on the basement side, water will simply pool inside the cinder blocks. That's not a solution.
Water needs to be kept out of the blocks by sealing the outside.

DG

[whiskytangofoxtrot]

Re: Sealer recommendations for cinder block walls

No, actually this belongs in Building Science. I don't mind you posting it here, but no need to snap at Jim. He was correct.

Yes, you do need to deal in reality here. And the reality, as Chuck suggested, is that there IS a water issue if you can see efflorescence inside, and there is no such thing as sealing hollow block from the basement side. If you paint a sealer on the basement side, water will simply pool inside the cinder blocks. That's not a solution.
Water needs to be kept out of the blocks by sealing the outside.

DG

Yeah, what he said. Preventing the transmission of moisture needs to occur BEFORE it exists inside the building material.

Then you hang the crown.

[[email protected]]

Re: Sealer recommendations for cinder block walls

Well, I guess I misunderstood your question on more than one point. It never occurred to me that you were trying to fix the problem from the INSIDE. As everyone has pointed out, this would be a pointless exercise in futility.

If, in fact, the block wall is structurally sound enough to hold up the house, and if you wanted a quick, stop gap measure, I would investigate block bond on BOTH sides of the block (as per manufacturer's directions) followed by thoroseal on the OUTSIDE as I indicated in my first post, all followed by drain tile, crushed stone etc. - also on the outside ;>)

[OGR8ONE]

Re: Sealer recommendations for cinder block walls

We used to solve this problem from the inside with an internal drain system and boring holes through the bottom block cells which drained into the system. "Dry Lock" or FRP panels could then be attached to the walls. Much cheaper than external excavation and a lifetime guarantee.

[Handyalexander]

Re: Sealer recommendations for cinder block walls

Thank you all.

OGR, that sounds like the best plan, and should be within the budget, I appreciate it.