Thoroseal in Basement?
I have received conflicting opinions about applying Thoroseal to basement walls after repointing. One contractor recommended doing this, while the other contractor said that it would trap moisture behind the Thoroseal and hasten deterioration of the mortar. He said Thoroseal should only be used above ground. I would appreciate advice on this matter.
I have received conflicting opinions about applying Thoroseal to basement walls after repointing. One contractor recommended doing this, while the other contractor said that it would trap moisture behind the Thoroseal and hasten deterioration of the mortar. He said Thoroseal should only be used above ground. I would appreciate advice on this matter.
If you have no problem to see dupm walls than just pointing is good enough.to see clean and bright walls than you can use thoroseal.If there is an issue fandation wall leakage than take care from outside by digging and waterproofing.The brick post at middle shuld keep clean and better have pointed.If you need another free estimate call M.Hamid Construction co. 718-633-1500/917-684-2428
All things equal, best to leave masonry unsealed – especially in a basement, where dirt/grit naturally occurring on the surfaces of the walls or pillar is not necessarily a problem (unlike, say, in a kitchen where cleanliness is an issue).
Thanks. Any thoughts about covering the brick pillar wall in the middle of the basement? Since it it is in the center of the basement, I wouldn’t think moisture would be much of an issue.
Our inspector said never cover rock/rubble/boulder basement walls with waterproofing as it will cause mortar to fail — same advice OP got. “Renovating Old Houses” by Nash says the same thing.
Rubble walls by definition let moisture in, even if your basement doesn’t feel damp. Same with dirt floors.
Thanks for everyone’s advice. I have a corner lot with bolder/mortar walls on three sides. The basement walls only get damp after heavy rains, so I don’t think it makes sense to pay what it would cost to dig up the exterior to improve drainage. I am having a new floor with vapor barrier put down and will be also have a dehumidifier draining into a sump pump. I find it difficult to believe that the bolders can be damaged, so my only concern is what effect Thoroseal will have on the mortar.
I also have a brick pillar wall in the middle of the basement that had some sort of material put on it that is flaking off. The contractor also doesn’t think it should be painted with Thoroseal.
it makes a difference if the wall is damp. if the wall is dry, it probably doesn’t matter either way. unpainted, the moisture is able to evaporate into the basement. this isn’t ideal, but it’s better than a crumbling foundation.
I have basement with the bolder/mortar walls. The walls were painted with some sort of waterproof paint maybe 50 or 100 years ago and nothing happen to them.
I painted them with Thoroseal 2 years ago and nothing happened to it as well.
Theoretically yes, water will be trapped in the wall and it will freeze/expand many times and it supposed to crash mortar. But I am not sure how much difference between sealed and unsealed wall. The wall is thick so sealing wall inside does not change much the amount of the moisture of the outside part of the wall. And inside of the wall never freezes since it faces warm basement.
you would definitely trap moisture in the wall which would lead to damage over time. Think about it–the walls get damp now, where will that moisture be when the thoroseal is on? Better to work on improving drainage options on the outside if you’re looking to dry the walls. consider whitewash instead of paint or thoroseal.
The main reason I am asking is because I would like have the walls look nicer and Thoroseal comes in many colors. The walls don’t leak but do get slightly damp after a very heavy rain. From what I have been told, Thoroseal is very resistant to flaking. So, the issue is whether the one contractor is right in his opinion that it would cause deterioration of the mortar by preventing moisture from escaping into the basement.