[philS]

I'm working on a house with terracotta block foundation walls, built maybe 1920. Anybody know if Thoroseal products will work to seal terracotta from the outside? Surprisingly Google got me nowhere so I'll call the company tomorrow but if anybody's had any experience I'd appreciate hearing about it. Thanks.

 

[concretemasonry]

Thoroseal is really not a DIY products although it has been used for commercial and induatrial and restoration for decades but they usually do not guarantee it as a "waterproofer" (like other products do) althought it has been used for decades for that purpose. I first used it on a dam restoration about 40 years ago. It is not a paint-like material and it is cement based.

The materials in Thoroseal are cementitious just as mortar that is used from block brick and clay tile for construction, so it is compatible.

Since you apparently will be excavating to expose the buried wall, why not also put in perforated drain tile before backfilling? The Thoroseal application is sloppiy to work with and the proper mixing can be a time problem. The good thing is that it is suggested to mist the wall prior to the application to make the spreading of the "pancake batter" material easier and get a better bond.

Dick

Dick

 

[philS]

Dick -- Thanks. All that is helpful. I've got a fair bit of experience working with concrete pours, block wall construction, and mortar. I wouldn't try to do finish mortar work, though I've gophered for pros. I gather getting the right mix is really important but nobody's going to see this, so as long as it sticks and cures properly I can't see that appearance matters. All that said, I picked Thoroseal only because it was recommended to me. If there's a more user-friendly product that can be just painted on, I'm all ears. But the terracotta will be very damp once I expose it. I suspect it'll take at least two weeks to dry (max temp here is 80 though humidity is low). I really don't want the trench sitting open any longer than necessary.

As for a drain, I've thought about it but there's no way to daylight it. I'm toying with the idea of putting in perf pipe, gravel, and garden cloth with a sump box of some sort at one end and a riser to the surface so if we ever get any significant amount of water we can install some sort of pump. But I haven't researched this yet. (I've also heard of pipe that comes pre-wrapped somehow, which apparently can save some money.) But it's a gable end of the house and, as long as nobody lets the hose bib leak, there really shouldn't be any significant amount of water to collect.
Further thoughts? Thanks again.

Phil