# Flat roof related questions



## Slyfox (Jun 13, 2008)

Make sure the roofers took a core sample of the existing system and made sure there was no rotted decking, etc.

It's not my experiences with either roof system that matters,
ask both roofers and any others you might 'should' call for proof of license, insurances and references of jobs they have done with that system.

I recommend getting estimates from a minimum of [3] three roofers.

Sky Lights can be installed on flat roofs.

Go to the Manufacturers website and read through the installment procedures your self and compare the roofers answers to that.

No matter what system you chose some type of recovery board should be properly fastened over the existing roof before installing the new.
You need to have a clean an secure surface for your new roof system.

The main thing you need in this adventure, is to trust the roofer you chose.


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## AaronB (Jan 29, 2005)

I see no reason not to tear off a roof that small, especially since it has already been leaking. Couple that with the fact that youre going to be installing a factory specified skylight and will need to get down to the framing, it will likely be more troublesome not to tear it off.

There are umpteen thousands of skylights on flat roofs all around the world. If your roofer doesnt know how to perform this installation correctly (hence the recommendation against it) then move on to another flat roofer.

Flat roofing is a whole other animal from residential shingle roofing. Not many shingle roofers are able to do the flat roofing properly, not to mention digging into your framing and installing the skylight properly.

I would not want to leave the old roofing in place for the aforementioned reasons. Tear it off and get the skylight you want.

In my neck of the woods, this job would run about 4K dollars.


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## christy123 (Oct 13, 2006)

I agree with your impression about the guy. he gave me a great quote though ($1275). I am not sure if he doesnt know how to do it or just wants to do a quick hassle free job before holidays.



AaronB said:


> I see no reason not to tear off a roof that small, especially since it has already been leaking. Couple that with the fact that youre going to be installing a factory specified skylight and will need to get down to the framing, it will likely be more troublesome not to tear it off.
> 
> There are umpteen thousands of skylights on flat roofs all around the world. If your roofer doesnt know how to perform this installation correctly (hence the recommendation against it) then move on to another flat roofer.
> 
> ...


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## AaronB (Jan 29, 2005)

I could do a recover job that size for that price too. I wouldnt though, because the customer wants a skylight and the existing roofing system has been leaking. I want to check the roof deck before I put a new roof over a problem.


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## ozzyj (Dec 9, 2008)

*Environmentally friendly flat roof system.*

Take a look at the Mirrorseal roofing system. You will find it at durapurecoatings.com or durapurecoatings.ca it is easy to use and doesn't stink. Good luck.


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## OldNBroken (Jun 11, 2008)

To start with, both are half right and half wrong to begin with. If you are going with a recover you should remove as much gravel as possible AND install a recovery board. As stated above though, for a deck that small you'd be best tearing it off and starting with a clean slate. As far as skylights go, that is an excellent idea and yes, we do them on flat roofs all the time. Last Walmart we did I believe there were 280 of them. 

Sorry, but I don't think the two you talked to combined equal a completely competent roofer. They appear to be just selling you what they know and not what is best for YOU in your situation. As far as the material choice, I am not a big fan of single-ply and would always recommend a BUR (hot or cold) or modified instead of rubber of any kind.


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## christy123 (Oct 13, 2006)

thanks guys...

Mirrorseal does look like an excellent product. I agree that i should get the roof stripped..they will need to strip 1/3rd of roof anyway to put in the skylight. I may have to postpone the project until spring because it is getting cold here in NE.

I have a question about insulation. I noticed that there is some sort of think silver colored sheet in the ceiling I noticed through the hole created by water damage ). if i end up stripping the roof completely what are my options as far as insulation in this vent less(?) roof is concerned?


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## Ed the Roofer (Jan 27, 2007)

A painted on coating material will not be an appropriate selection for an existing built up roof with a gravel surface.

For ANY flat roof system to function to the best of it's capabilities, it would be more prudent to create a positive drainage system, therefor shedding the water off as efficiently as possible.

A 1/8" per foot or even better, a 1/4" per foot tapered insulation system and a recovery board insulation, or thicker and higher R-Valued insulation can be used to beef up your R-Value for your insulation concerns and also to effectively create the positive drainage required.

If you were to installa tapered insulation system, then the optimum placement for a new skylight would be at the highes point of the insulation, where it could be constructed to crown at the center of the roof, thereby sheddin all potential water away from the skylight curb eliminating the likelyhood of leakage.

But, the best way to prevent future leaks, is to hire a contractor who has a lengthy background of experience with flat roofing systems.

Also, although I recommended the insulations systems and the recovery board, which "Could" be secured to a cleanly swept existing gravel surfaced flat roof, the more proper way would be to remove the existing roofing down to the decking and repair or replace the decking and wet insulation in the rafter bay cavities as necessary.

Ed


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