Torch on roof membrane on deck

canada55

I have suspended wood frame (two story) deck built to stand the weight of 2" of concrete finished surface - the deck frame was sheeted with plywood and I had a torch on membrane installed and then we poured a 2" concrete cap on it - nice to walk on, low maintenace and protects the membrane from damage. I love it. but.....

Within days of having the torch on (before concrete) I found seams lifting, air bubbles, edges lifting and leaks (it rained a day later), I contacted the building inspector to come out and he said "don't pour concrete on it yet" it was not installed correctly and the roofer must come back to fix it. The roofer returned and retorched the areas that were an issue. It was February and temp was very close to freezing when he did it.

We went on to pour the concrete and now the deck membrane is leaking again (yes, under the concrete), when I contacted the roofer he said he would never have used a granular touch-on membrane if he knew that concrete was going to be poured on top he said we told him that we were going to install wood on top of it (liar)....and said he is not to blame. He said he would have used a smooth surface membrane, the reason is because the concrete shrunk and pulled the torch-on seams open...BS or not?

The torch on membrane was only one top layer torch directly to plywood (no base)..do we have a professional roofer here that can comment please....I'm in trouble here.

OldNBroken

1. Should have nailed a base then torched to it. Doesn't matter if it was being covered with anything. One of the many reasons for this is that that decking is moving, especially with pouring concrete on it.

2. We use granulated all the time under concrete, stone, tile etc. Never have any problems.

I'm guessing your main problem is the torchdown being adhered directly to the sheets of plywood. Any roofer out there worth his salt in torchdown knows that's a no-no. I guess as an extension of that would also make your installer your main problem also.

Sorry to hear it.

canada55

This give everyone a better idea of the install

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OldNBroken

Got a picture of a roll or label? Can't see much detail from that picture. Why does that look like an SA?
Do you have any evidence this guy has ever done a torchdown?
Either way, should absolutely have a nailed base under that.

canada55

Sorry no picture of a roll or lablel

Sorry, what is an SA?

No evidence that he done torch-on just was told by another contractor he could do it.

attched is a photo of one of the corners that lifted, you can see it just wasn't sticking..

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OldNBroken

The guy has no business holding an open flame on your job.
Done properly that membrane should basically be melted and fused to the substrate. That membrane doesn't look like it had any heat put to it whatsoever.

You need to find someone experienced in torchdowns. It's the last type of roofing you want a novice doing on your building.
You need to make sure they nail a base, then torch to the base.
The system is proper, the installer is pulling your leg.

SA is a self-adhering membrane. It would have a plastic backer on it they would have peeled off prior to installation. Tell me it didn't please.

federer

yea you need a base. for my roof i am doing a firestone 180 granular cap sheet, with a firestone base SA undeneath that will be mechnically fastened. then when it gets torched they fuse together

johnk

Yeah that roofer was an idiot.Looks like he just torched(tried anyways) the seams and spot torched the rest.Smooth,granulated doesn't matter,it shouldn't leak!!

federer

john wanna give me more input in my thread please :P

canada55

Thanks Guys, your comments are very helpful in understanding what went wrong, I trusted that my roofer was experianced and knew what he was doing.

I invite others to make further comments as they will be helpful in educating myself in trying to resolve this major screw up with the roofer.

The roofers defense is that you "can't" use granular top layer under poured concrete capping. Comments to that issue would be VERY helpful...

This is what I have today a completley finished deck that leaks

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canada55

If others here have actually done a granulated torch-on under a poured concrete capping I would like to hear about - it just a quick comment if you had or heard of any problems like mine.

If anyone knows of a manufactures document that describes how-to do granulated torch-on under poured concrete capping that would be HUGE gift. Thanks

OldNBroken

already told you, have used it under tile, stone and concrete on several jobs and have never had any issue. Someone else on here may have a rational argument to back his story but I can't think of any.

Slyfox

Can't say anything more then OldNBroken and Johnk.
There simply is no excuse for the roof to be leaking other than the roofer installing it improperly.

You should how ever be thankful he did not attempt to properly torch the material because if he had he probably would have burnt your home down being that he did so with out a base sheet. The base sheet serves as more than just an underlayment, it's also a fire barrier to prevent direct exposure of the torches flame on the roof & wall sheathing.

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Grumpy

LOL nice primer job. That's a good one for sure.


The installation of something on top of my roof without my direct supervision would violate my guarantee as well as 99% of other roofers. Reason being in most cases, probably not this case, but in most cases the surface applied over my roof might be what actually caused the damage and further more I have no way of inspecting.

Something also not being said but even with a base sheet, even with a double base sheet, when I am torching I always put down a 1/2" fiberboard over the wood, then a double base sheet.

For future refrence... Hire the Right Contractor!

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-Grumpy

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Sometimes the savings that comes from doing it yourself can be blown away with one mistake.

The information found in this post is not to be considered legal advice. All information should be considered relative, not specific. Never attempt any repairs you are not comfortable with. Always maintain safety! The author of this post takes no responsibility for any losses that occur. Use at your own risk.

OldNBroken

Grumps, Nothing wrong with a little extra protection from doubling the base sheet but you can't put recovery board down under something heavy like that. The compression and/or deterioration if it got wet would end up destroying the slab.

A competent installer doing it properly is what you need.