I am sitting here watching a Decra steel roof being installed but they did not install any foam insulation under the steel like my previous aluminum roof? We are concerned about our energy costs rising - they are very low in this home. We also want to know if it should have some. thanks!
Guest User
2014-07-25 09:16:25.000000
Yes they laid batten and a plastic sheet under that. Not sure what that us. Sorry. I'm no expert. Thanks!
Guest User
2014-07-25 09:33:33.000000
Ug my roofer said this one would be more efficient. ??
Guest User
2014-07-25 09:55:10.000000
I'll go out and look. They are literally installing right now. Horizontal only.
Guest User
2014-07-25 10:08:51.000000
So I'lm attaching an image of the packaging so you'll know what we chose.
I'll watch our bills and see if there's a big difference. We are in the peak of summer in Texas so it should be interesting.
Thank you!
Guest User
2014-07-26 14:45:18.000000
I am considering a metal roof. Their practice is to install a synthetic material (plastic type feel to it) which is water proof
on the decking before the ag panel is installed. Is this enough noise barrier product or should it be an ice/shield or foam
product which is thicker?
When the ag panels are joined side to side shouldn't there be a lap sealant put underneath to keep moisture out? If they don't
use a sealant to join couldn't this be a problem for leakage?
Guest User
2014-08-12 13:07:36.000000
Deena, while the foam inserts did offer some energy efficiency, these products do have some efficiency without them. Is this a batten-mounted Decra product?
Todd Miller
2014-07-25 09:19:21.000000
The battened systems are pretty energy efficient. My guess is that your overall efficiency may decline a little but probably not a huge amount. Anytime you change any components of the roof system, you are at risk of this. The system you had was one of the more energy efficient ones available.
Todd Miller
2014-07-25 09:35:52.000000
Do you know by chance if they put down vertical battens first followed by horizontal battens, or only the horizontal battens?
Todd Miller
2014-07-25 09:56:58.000000
That is the normal method. The battens create a nice thermal break between the metal and the roof deck, which really is very similar to foam in terms of efficiency. There is a method of vertical battens first which allows for good passive ventilation airflow up the roof.
It will be interested to see how the roof performs. Please let me know once it's up. My email is todd@asktoddmiller.com
My hunch is that it won't be hugely different from your previous roof. I don't expect it to be quite as good but I do not expect it to be hugely different. Good luck.
Todd Miller
2014-07-25 10:21:23.000000
Some panels are designed for sealant in the side lap and some are not. You do not want to add sealant to a panel not designed for it.
The synthetic underlayment you described is not a noise barrier. Normally any additional sound from a metal roof is absorbed by attic space and insulation.
Todd Miller
2014-08-12 21:04:01.000000
Need some guidance on using foam board on top of roof deck beneath metal panels. This is an unheated, uninsulated barn barn with pine board roof decking. I would like to cut some of the heat coming through the dark color roof in summer. In winter I will occasionally run a heater on the second floor while working inside. My roof pitch is 7/12. I'm planning ribbed 29 guage panels with external fasteners. I'm thinking the roof is going to leak a little eventually in big wind and snow conditions and I would like to shed water that gets beneath the panels.
Should I use WIP over the foam board or beneath the foam? Any other options? I could use a foam board product recommendation as well. There are no valleys or dormers or cupula. Planning 1 x 6 nailers over the foam to screw down the panels. I'm not sure this 3/4 inch air space counts as roof ventilation.
I sincerely appreciate your thoughts on this.
Sid Hogan
2014-06-13 14:07:49.000000
Thanks
For the foam board, any recommendations or types to avoid?
Sid Hogan
2014-06-16 10:51:03.000000
Go with the above deck ventilation as you are leaning towards. Putting some foam across the roof deck should help with the surface temps in the winter and keep condensation issues to a minimum.
Use the underlayment over the foam board.
I would also look into sealing the pine boards by applying a peal and stick membrane. This will keep any of the air movement and condensation on the underside of the panels to a minimum.
Eric Novotny
2014-06-14 09:57:37.000000
No types to avoid. XPS and PolyIso are the most common.
Eric Novotny
2014-06-16 16:32:22.000000
Deena,
What panel did you select?
The thermal brake should be in tack and there will be some convective air movement.
Eric Novotny
2014-07-26 13:31:08.000000
Going with the shake they do have an Energy Star color but that does not appear to be in that color range. There is still a decent bit of air movement under that panel so you should be good.
