2

I inadvertently chipped away too much mortar bed, exposing the bituthene waterproofing underlayment, while replacing a slate tile on my deck. I'm not sure whether to repair with additional thinset mortar when I lay the new tile or apply a silicone roofing sealant before the thinset.

enter image description here

  • "exposing?" or "cutting a hole in?" - kinda makes a huge difference here. – Ecnerwal Jul 7 '17 at 14:49
  • The tarpaper wasn't torn, but rather I was able to remove the loose mortar, exposing the tarpaper below. – Grant Jul 7 '17 at 15:00
1

If you have not punctured/pierced the membrane, fill it with mortar/thinset and tile away.

  • I noticed that the membrane had inflated due to the hot weather. A little bit of oozing of tar was noticeable too. Wouldn't it be safe to cover the membrane with a silicone roofing sealant before laying the thinset? – Grant Jul 7 '17 at 18:36
  • If doing anything with a bituthane installation (which is not tarpaper) your best, most compatible, bet would be to carefully expose a larger area, clean it carefully, and apply a patch of bituthane, rather than tossing some sort of silicone sealant at it that probably won't bond nearly as well. Bituthane is designed to stick very well to itself. – Ecnerwal Jul 8 '17 at 13:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.