# Torch down roofing over metal



## Polecat (Jan 20, 2011)

Howdy,
I'm looking for some advice on torch down roofing. I am a metal building erector by trade so this is a bit out of my area of expertise. This is the situation:

I have a customer/client that I have done several projects for. I am pleased to say that, apparently, they are satisfied with the quality of work we have done and now call on us, regularly, for nearly anything they need done. Their latest request is that we do some roofing repairs to two mobile homes on their property. With my past experience in owning mobile homes and dealing with the roofing issues that I have had, along with the customers request that we keep the cost of repairs to a minimum, I advised that they go with "Torch Down" roofing. (Of course I feel that a metal roof on a post frame structure, over the mobile, would be by far the best:thumbup:, unfortunately they aren't able to afford it at this time.:sad
I have applied torch down roofing before. The conditions were ideal and I had no problems at all. Everything went without a hitch. But that was a DIFFERENT situation. THIS time, it is the middle of winter and the weather is unpredictable. In the daytime,the temperature outside ranges from 35 to 50 degrees (F). At night it can drop below freezing. Not usually, but occasionally. Also, the condition of the roof on one of the mobile homes is very poor. It has leaked for (who knows HOW long) quite some time. There are some areas where it has rusted almost to the point of rusting-through. There are several former repair jobs where someone has done some "patching" using any number of roofing materials. (Black Jack, Snow Roof, Caulking, etc..) I am concerned about getting the torch down to adhere to the roof. My immediate questions I have are these:
1. Is it possible to get torch down roofing to "stick" in temperatures this low, or what is the LOWEST temperature outdoors that one can apply torch down roofing??
2. Should I remove all the previously used materials prior to applying the torch down roofing.?
3.Will it stay adhered to the "rusty" areas on the roof??
4. Is there some kind of product that can also be applied, along with the torch down roofing, that would insure it's adhere-ability???

And... one last issue: The mobile home's roof has been battered by wind and weather for quite some time (Many years*) Anyone with any mobile home experience could tell you that mobile homes sometimes act as a sort of "Wind-Bag" in that when the wind blows and depending if there are doors or windows that are open, the mobile home tends to expand and contract. (Somewhat like the bag on an old Kirby Vaccum does when you switch it on and off!) <-  Due to this, the roof is rather "loose" in areas and rises and sags as you look down the roof from one end of the mobile home to the other.
QUESTION #5. Will this cause some problems inthe future where torch down roofing is concerened?

ANY tips or advise that anyone can give me, I will be extremely grateful 
for! Thank you for your valuable time and cinsideration.

Polecat
in Washington State


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## OldNBroken (Feb 8, 2008)

I would say DO NOT EVEN CONSIDER IT for many reasons ranging from safety to quality. You having to come and ask for advice is reason enough to not do it. It's nothing personal, most of us on here feel that anything torchdown should only be done by very experienced installers. There are numerous examples out there of people regretting attempting to do torchdowns. 

IF you are going to play roofer for these people consider laying 1/2" recovery board and covering with epdm. Torching to those trailers is completely insane.


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## JWilliams (Nov 11, 2008)

yes i agree. youd be better off installing epdm in my opinion. i wouldnt take any open flame up on that roof.


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## flatroofing (Nov 22, 2010)

Tell owner, you're way with a warranty or the owner his way with no warranty
Diff strokes Diff folks.


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## PrestigeR&D (Jan 6, 2010)

*The First thought ....*

that puts out a red flag is- Does your liability insurance include "Torch roofing applications" ? :blink:

installing Modified Bitumen over metal- NEVER even consider this for an option-:no: If that is a wood sheathing it is a HUGE gamble. This application should have a ISO insulation/fiberboard and then a base sheet mechanically fastened. Here in NY you have to have a insulation factor of R30 / 3" ISO on commercial buildings,,,residential is different. The only time that MB is applied to metal are at the edge-the drip/rake edging members and a primer applied to all before the MB is applied to the roof... I would NOT apply it this way..:no:..

Personally... your situation is perfect for a EPDM application....


B.


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## MALCO.New.York (Feb 27, 2008)

That is what Insulation Board and Base Sheet is for.

Done it at least 100 times on corrugated metal roofing. My only complaint was the tear-off of the existing built-up and aggregate roofing! All else was a simple and safe breeze!









http://www.jsroofing.com/images/acfoam_96z3_a04u.png


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## Grumpy (Oct 8, 2003)

You can install flute fill insulation and go over with a single ply TPO or EPDM.


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## 1985gt (Dec 10, 2010)

Yes flute fill, your choice of insulation on top of that. Ie Densdeck, coverboard or ISO. Glue down a EPDM or TPO or better yet mop on a 3 or 4 ply and gravel that sucker.


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## Tom Struble (Mar 2, 2007)

hi Grumpy...how the hell ya been:notworthy


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## Grumpy (Oct 8, 2003)

tomstruble said:


> hi Grumpy...how the hell ya been:notworthy


Grumpy

What else would you expect?


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