Thoughts on metal a roof

DRS

Old Mossy Horns
DRS, no way to say for sure without seeing it but your problem may be as much due to warm air from inside the living space getting into the attic as lack of ventilation. Kinda like a glass of tea, when warm air hits cool metal it will cause condensation(sweating). I've pulled rolled metal roofing off of 100 year old farm homes and put the metal right on the existing purlings, no barrier at all, with no sweating problems.... but..... if there's a way for warm air from the living area to get into the cold attic it'll drip in that area...

The contractor is ranked on of the best in the country. We have had air quality professionals and engineers look at the problem. We have had the walls sealed to the attic, more insulation added to the attic and under the floor sealed. We monitor the temps and humidity of the living area and attic, recording these daily. It has everybody stumped. I have to say the contractor has tried to help solve the problem. Now we are talking with the contractor about providing the labor and us the material to tear off the entire roof and replacing it all. Might try insulating the under side of the roof between the rafters, first though. One problem is there is only a few months out of the year to tell if the work done helped. Heck, the roof/structure may last my lifetime. Just really don't know what to do, that is what makes it so frustrating.
 
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SlickRick

Four Pointer
My background is 15yrs of commercial construction. I think the metal roof SYSTEM is great. When I replaced my residence's roof a few years ago, though......I went with shingles for one reason.

I don't know anyone I trust to install the metal roof the way it should be done. Two of my neighbors' 20-something sons have roofing companies and install metal roofs. Their credentials are:

1. They have an F-250
2. They have a dump trailer
3. They have their business name on the side of #1


This could not have been said any better / get a warranty that is good and someone that will stand behind it. Lots can go wrong with a bad install on a metal roof!! If done right you will love it.
 

crittergitter

Ten Pointer
DRS have you thought about closed cell spray foam between rafters? They have been doing it up north for some time. They do it to keep the roof and roof decking cold during the winter months to prevent ice damning. I guess they are thinking if they keep the roof frozen nothing will melt so no refreezing issues on the roof which might apply to no frost under the roof. I wonder if that would work for your situation, might be worth further investigation? Tiger foam makes a DIY kit you can order and do it yourself. http://tigerfoam.com/
 

DRS

Old Mossy Horns
Crittergitter, we have thought about that. Actually I haven't seen the DIY kit. Thanks for the link. We thought of doing the entire underside, but then if you do have moisture problem from roof leakage, that would be catastrophic. Haven't thought of just spraying just between the rafters. We had thought about foam insulation sealed to the rafters and joints so it could be removed in case of roof leakage.
 

Longrifle

Old Mossy Horns
Contributor
LOL! NC, unlike Florida, has some seriously lax requirements for installing metal roofing. I went to the local building department when I first moved back home to ask. The inspector told me that all I had to have was a pickup truck, a strong back, and a weak mind! Hey! I qualified!

After Andrew went through South Florida they got purely anal about codes for installing and who could legally do it. You have to have a State Contractor's license down there and you'll face massive fines, even go to jail if they catch you bootlegging.....
 

trybowfishin

Button Buck
all great info for metal roofs, first I will be doing my shed roof, hopefully build up confidence and tackle the house roof!
 

Southside

Ten Pointer
We have an older house built in the late 50's with a hip/valley roof. The roof does not have a solid substrate but slats some butted, some with small spaces in between, not tongue and grove. We had the thickest standing seam gauge available put on the house. Felt paper under metal and no air space. Metal super chills the roof when temps drop in the 20's, frost forms on the ceiling of the attic. It has been blamed on moisture problems under the house, had work done on that. Air quality guys say that there is no problem with moisture any more, frost is still on really cold mornings. A majority of the roof is a 3:12 with a ridge vent. We have added more soffit vents to the point it was ventilated 100% around the house. Added turban fans closed most of soffit vents, better but still think not enough air flow. It has been an absolute nightmare. Kicker is if we had got a building permit, they would have had to have taken the roof back off. This came from a conversation with a county inspector, due to the fact on a 3:12 roof the manufacturer require two layers of felt paper or ice and water shield. Contractor argued roof was over 3:12. Ok 3.2, 3.1, 3.4 to 12 using a slope App on a tablet, 3:12 using a 4' level and a tape. Due to the fact we did not have a permit the county won't do anything, lawyers want take the case. We are in year 6 now.

This is not the only case where metal roofs have caused problems, there are plenty examples that can be found while on the net.

Longrifle, I think has got it right. Some sort of moisture barrier and putting strips on the roof to secure the metal, that forms an air barrier between the the substrate and metal.
DRS, how much did the roofing job cost? Not exact but roughly. I ask because there is another course of action you could take if the job was over x amount of dollars. That is if your sure the contractor did something wrong.

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Banjo

Old Mossy Horns
My dad had one put on a few years back and he is happy with it.


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croatankid

Guest
I intend to put a metal roof on this year. I saw on YouTube where the contractor put Styrofoam in the spaces between the perlins. So instead of dead air space you would have Styrofoam which is kinda the same thing. Is that a good idea? Also, I think I'll put in a ridge vent. I already have gable vents. I think the Styrofoam would also help with preventing damage to the metal from walking on it.
 
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