Need advice/options on flat metal roof.

Plasbot · 01-12-2012, 07:35 PM

My house has an add-on in the back. I think it was some sort of pre-fab thing, it has thin metal exterior and a metal roof. We had the interior walls redone and re-insulated, and new vinyl windows put in , but it's still way colder in winter and hotter in summer. I just had a new a/c and furnace installed and they ran a vent into that room. But even with the interior door and window to it left open it's 10 degrees colder than the rest of the house. (and that's with a space heater in there) So I'm thinking it must be that the roof has poor insulation.

I didn't know you could get pvc or foam put on these roofs (are they the same thing?). Seems like it would fix the insulation problem. The room is 13 feet by 17 feet. I live in Fort Worth, TX and would appreciate any recommendations.
Here are some pics:

DonaldC · 01-12-2012, 08:00 PM

Did the furnace guy install a return also, the roof appears to be a foam insulated steel roof

Plasbot · 01-12-2012, 09:08 PM

He mentioned that they would probably need to do that, but he didn't. I called a couple times saying the airflow was not enough for the room. the first time they installed an air scoop to divert more. Didn't do much. The second time they increased the size of the duct from 6 inches to 8, that helped a bit but still even with all other vents almost all the way closed it doesn't blow very hard. Finally the third time I called him a woman answered and said he was in the hospital in critical condition. She didn't specify from what so I'm waiting about a week to call again.

DonaldC · 01-12-2012, 09:29 PM

In a room which has many of the attributes of a three season, run a return vent with a damper (flapper) to control intake for seasonal adjustment, on a 6" return run a tee so you can have one return on the floor and one located 2-4" below ceiling. open the top in the summer and open the bottom in the winter & close the top, some will even incresee the time on the return cycle on there furnace, get the bad air out so that the good air can do its job.
Don

Plasbot · 01-13-2012, 08:35 AM

Wow thanks I will definitely discuss that with him when I talk to him next. It's a really tough area to access. They had to drop a metal tube through the ceiling of the kitchen to get the vent in there, and the guy said he had a hard time getting through the wall.
So do you think some foam insulation on the roof would help? The main part of the house seems to hold it's temp very well now that we added several inches more insulation to the attic.

DonaldC · 01-13-2012, 05:37 PM

If there is no inslation sure, my experience with these roofs is they normally are high density foam applied directly to the metal surface, but if you do not currently have insulation, this would help smewhat. Remember from a HVAC. perspective 70 degrees controled air mixed with exitisting degrees will give you your actual temp, give or take because the actual temp at the register will have some bearing

BornaRoofer · 01-18-2012, 10:43 PM

Thats identical to the sunroom on my dads house. Last fall I installed two staggered layers of 2"iso insulation and a adhered epdm. It has to be run under the shingles at least 2'.
In your area one layer would work but more is better. And white Tpo in place of black epdm.