- I would take the Durock down everywhere, besides, Durock is inexpensive and easy to replace. You need to get the full picture of what is going on behind the scenes and make repairs as necessary.

- Re: "we would have tiled it already" - Were you going to tile without a waterproofing system in place? Durock is not waterproofing. IMO, the gold standard is the Schluter system, Kerdi for the walls, Ditra for the floors. It costs more up front, but it will last.

"IMO, the gold standard is the Schluter system, Kerdi for the walls, Ditra for the floors."

But with a Schluter shower, Kerdi on the walls, but no Ditra on the shower floor, right? Just Kerdi on a sloped bed of mud, or Kerdi over a Kerdi Tray.

Ditra is fine for the remainder of the bathroom floor, meaning for the floor outside of the shower.

@formulaross20 thanks. the plan was to waterproof the Durock with Redguard.

I'll take everything down this weekend and will see what the tiler wants to put back up when we get to that stage.

You don't take down cement board because it got a little wet. Make sure the roof leak is fixed and proceed please.

@Joseph Corlett, LLC I'm more so worried about the insulation in the wall cavities than the cement boards themselves. I can't see how the dense soundproofing bats (3" rockwool) are going to dry out back there if they are wet making them a breeding ground for mold. Would you not share the same concern? I put a dehumidifier and a fan in as soon as I noticed but I really don't know how long it's been wet for.

@chispa Great suggestion. Your comment is what scares me, as you are absolutely right - who knows if my pinhole was one of many.

I would take the cement board down and possibly move the insulation to allow the area to fully dry before putting things back together.

And I think if you do that and get it all dried out (think maybe dehumidifier to help) the rockwool should be fine - one of it's benefits is that it is inert / doesn't support mold growth.

and as chispa says - find that leak!

Thank you @just_janni, that is REALLY good to know about the rockwool. I have the dehumidifier cranked to the max in there. My task for today - up on the roof to hunt for holes!!

I think its time for a roofer to come and check things out, and it just may be time to have the roof redone. Better to be safe than sorry. It could get a lot more costly if the roof isnt taken care of.

@cat_ky We are on the same page. This is my second leak after my general contractor "fixed" the areas before undertaking this reno. Unluckily for me, he clearly didn't do a good job. I came to my sense and called an actual roofer out earlier this week when I saw the wall. It was the weirdest thing, but he had a look around, said the roof is in reasonably good condition, then told ME what to do. He pointed out some areas to repatch, then suggested I put a silicone roof coating to fill in any missed pinholes. He said the task is easy enough that I could save some bucks doing it myself. Go figure!!

I think you got a lazy roofer, might be time to call one that actually works, and is good at what he does. Roofs are not anything, to mess around with. Water damage isnt fun. I had storm damage last summer, and had to have a whole roof replacement. I am still repainting things, after repairs on the inside.

Or maybe the roofer has a full slate of jobs lined up and can't get to it for six months. As well as possibly a labor shortage problem. There are 'Help Wanted' signs all over my town.

Roof is in 'reasonably good shape'--i.e., not replacement time. Detailing how to & what materials to use is something I would see as a Good Will gesture. And it is a flat roof, too, so not scary and super dangerous.

@ci_lantro I read it exactly the same way. He stayed with me for at least an hour - over which period of time his phone continued to ring non-stop. I think he was a busy guy (highly recommended by the local roofing supply store) and what he viewed to be the fix for the job wasn't worth his time to do. He walked me through everything very slowly, answered a million of my questions, and also offered to pop back around if I got into any trouble. Though I found it unusual to have called in a professional and have him leave with a list of things for ME to do, he was a refreshing change from the usual NYC f*#$^ers I regularly encounter. If only we had got him in from the start instead of a GC who gave the impression he knew what he was doing. Well you live and learn.

I spent the day yesterday crawling around the roof and went through nearly 3 gallons of flashing cement. Maybe I went overboard filling every and anything, but I suppose in these situations too much is never enough. Today rain is on the cards, so we shall see. Pray for me folks!

Love your attitude - good for you for tackling this all!

Good luck. Hope you stay nice and dry.

I opened up the wall (with my Gumby physique this was not as easy as I anticipated) and I certainly no longer have to worry about reusing the boards as I made a mess of them in the process. Mystery of mysteries, it was not wet back there AT ALL. No sign of water anywhere directly behind the wet part of board. The batts were dry. There were no dried drip marks running down the inside of the walls. I don't get it?! The water must be somewhere for the wall to have been wet (captain obvious). At least now I can get air circulating back there, so I have the fan and dehumidifier running and called it a day.

As long as the leak was stopped, it would have dried out anyway. Sometimes you get really excellent advice here; whether or not you take it is another story.

Indeed! I took the advice of the majority and can now rest easy knowing what is going on behind the wall. At the end of the day, for my peace of mind, it was worth both the cost and inconvenience.

"I spent the day yesterday crawling around the roof and went through nearly 3 gallons of flashing cement."

Not trying to throw a scare into the situation, but you mentioned you have a flat roof, but I never saw mentioned what type of roof you have as a membrane material.

Seeing as you had someone on site and that person gave you advise, I'm sure all is well. But do be aware that if, for example, you have an EPDM membrane roof (which is what we typically use in my area), that asphalt-based roofing cements are not compatible with EPDM.

Some modified bitumen roofs can take a simple asphalt patch as a temporary repair.

Just wanted to toss that out there.

Thanks @MongoCT. Nothing scares me any more!

I have what I believe is a modified bitumen roof (Firestone APP 160 is the roof paper used). The roof coating on top of that is fibered aluminum. The areas that my contractor "repaired" not that long ago are still exposed roofing paper yet to be covered with a coating, so in those sections, I was putting the flashing cement directly on the asphalt paper. I did scan the rest of the roof for any spots of concern and went over some of the seams in areas with the fibered aluminum coating with the flashing cement. Any thoughts on compatibility there?

As to making these patches more permanent, the roofer suggested painting a silicone coating over the top. Is that how you would make it permanent?

My apologies, but I'm not knowledgeable enough about modified bitumen to offer repair advice.

There is no such thing as "flashing cement". There is mechanical flashing and there is roof goo. You can't goo your way out of a proper mechanical flashing detail.