Is it called "scratch coat"? How do you do it?

Hi. I have a cinderblock foundation on a log cabin. On the exterior of the foundation it has a rough concrete coating covering the cinderblock. Is this called a scratch coat? I'd like to learn how to apply it. Any advice? If I want to apply it over exterior plywood (with housewrap), do I add wire mesh first?

Thanks.

 

it sounds like you have stucco.

scratch coat is what you put on before adhering stucco, tile, or veneer stone. it isn't needed when adhering to block walls, because they're porous enough to make a good bond with stucco or veneer.

but, yes, to stucco or veneer over sheeting of any kind, you need to first apply tar paper with a mechanical stapler, then staple (preferably with an air stapler) diamond mesh lath to the surface, making sure there are no "bubbles" or voids behind it. i.e. it's tight to the sheeting, flat, and it doesn't move.

i'm not a stucco guy, but i'm sure someone else here can advise you on the proper materials. most stucco is just cement, sand, and water applied with a flat trowel. scratch coat is similar, except a notch trowel is raked across it before it's cured, making it look like someone took a dinner fork to it, and, i assume, for the purposes of giving that coat more surface area to bond with.