Basement walls, care to try?

[TomB]

Here's the deal: I'm in an 88-year old Philadelphia row-home. The basement, basement wall consists of about 2 feet of bluestone underneath and a double course of bricks on top. The brick had a skim coat of some type of morter or plaster at one time, but moisture and plant roots have taken most of it off.

I've chipped away whatever was left of the top coat, ground the brick joints, and gotten off all of the loose stuff. I'm not looking to tuckpoint the bricks. It isn't an exterior wall.

My question is what do I use to recoat and seal the surface before I paint? can I use a float and a sand cement mixture to seal it? Thickset mortar? Plaster? Bondo? What do use in an application like this?

A couple of pictures are available at:

Many thanks, -Tom

[mark Ransley]

Use mortar mix, but the white is effloresence, you need to use muriatic acid to remove it . Nasty stuff.

[TomB]

Thanks, Mark. Do I have to neutralize the acid before I apply the mortar? Also, is there a particular mortar I should use? How thick do I want to get it? How long does it need to cure before I can paint it (with oil or latex)?

I'm really out of my area of knowledge on this one.

-Tom

[mark Ransley]

Neutralize no , just wash off completely with a hose. But acid is toxic you need good ventilation outdoors, a big fan. A cartrige respirator , old clothes and gogles. It will burn lungs. You use a stiff plastic bristled brush on a pole to scrub down after it stops foaming, about 5 minutes. You also apply acid with the brush. Just use mortar mix. How thick no more than 1/2 inch, but im not sure on that, maybe a little thicker. Paint over with latex. Or if you have moisture comming through and with effloresence you do use UGL. a Portlant cement , rubber based paint. Wait time , read the ugl can or 30 days or more for latex. The key is cleaning bad mortar from the joints even if its deep. Old stuff turns to sand if its continualy water damaged.

[TomB]

Thanks again Mark. Most informative. I'll let you know how it comes out. BTW, if I handle the effloresence, but don't handle the moisture that caused it in the first place...

Well anyway, I'll let you know how it comes out.

-Tom

[mark Ransley]

Then Ugl is your best bet up to 7 coats