susansingh•1d ago

Read an old building code book from 1978 and found out they used to allow a 1/2 inch mortar joint for foundation walls. That's huge compared to what we do now.

4 comments

4 Comments

faith_shah881d ago

Wasn't that for block, not poured walls?

kai_webb911d ago

Yeah the block vs poured thing, I used to be right there with you. But I saw a job last year where they used it on a poured foundation and it held up way better than tar. The key was prepping the wall right, cleaning off all the form release stuff. After that winter there was zero moisture in the basement.

rowanhernandez1d agoMost Upvoted

Hold on, tar's been failing for decades and you saw one good job?

smith.nancy1d ago

Remember how they used to say tar was the only way to go? @faith_shah88 is right to ask, because the prep work is everything now. My uncle's place from the 90s has a poured wall they just slapped tar on over the form oil. It's weeping like crazy. But the new stuff, the liquid applied membranes, they bond right to the concrete if you clean it right. It's like the difference between painting a greasy wall versus a clean one. That old tar just sits on top and cracks.