For Professionals | Member Login
Find a Professional
Sign Up Log In Add New Topic

TOPIC: Installation Process

metal roof

Return to Installation Process

Return to Archive

Return to Forum

We are building a new house and have just had a metal roof installed. I am worried the installers were amatuers and instead of 3 weeks it has taken 13 weeks and they have scraped off a lot of the paint by rough handling and the metal joints look rough and there are excessive areas of rippling in the strips signifying screws placed too tightly. The ridge tops are wavey and do not look right. I think they have spray painted some of the scarring to hiide it. How bad is that and how do I check it out?
Guest User

1/8/2005
Many of your concerns are rather subjective. However, I would strongly suggest that you contact the manufacturer of your roofing and get their input. As far as the touch-up -- I would be veyr concerned that the spray painted areas will fade rapidly and look very bad within a couple of years.
Guest User

1/9/2005
we are going to have a metal roof put on top of our shingles and the contractor says that we have to apply felt before applying the roof, but cant we just have perlins put in instead?
emmy blair

12/8/2009
I always recommend a new layer of underlayment, even if purlins are used. Not all products need purlins. Todd Miller
Todd Miller
Isaiah Industries, Inc.

12/11/2009
Perlins are fine, however they are not as good and to use them you should check the code in your area. They form an area of trapped air, which is a fire hazzard. The International Building Code requires that you put a layer of insullation or gypsom board between the perlins. A layer of felt is better anyway if you are not on shakes, the felt is only for scratch resistancy to the underside of the pannel as it expands and contracts.
Steven Tuttle

4/18/2010
Hi My son had a metal roof installed last May, and I recently had one installed last month. Both our roofs were installed by different contractors, but the Galvalume was purchased at the same manufacturer. Both roofs were installed directly over the shingles, no strapping or underlayment. Can there be a problem with the rough shingles causing the galvalume to rust from the the inside out due to the movement caused by expansion and contraction with temperature changes?. The contractor and steel manufacture (where the steel was purchased) said this is the way they install these roofs all the time. Other than that both roofs look great. How long do you think the galvalume will take to rust through if this is indeed a problem? Am I worrying needlessly or will I have to reroof in the near future, due to me not being educated BEFORE I had the roof installed?? Thanks Ron Lalonde Nova Scotia, Canada
Ron Lalonde
Metal Roof

1/6/2011
Ron, The fact that the manufacture says it's no problem is the most important thing. Some manufactures allow for install directly over shingles, while others do not. Personably I would prefer there be a layer of 30lb felt or synthetic underlayment between the shingles and new metal roof. I would say in the worst case it would be 15-20 years minimum before you would really have to worry about this. (probably a lot longer) The other thing is, new more reflective metal roofing paints such as those that are Energy Star rated don't absorb as much heat, lessening the expansion and contraction tremendously.
Nate Libbey

1/7/2011