I had this shop built a few years ago and at the time didn't think of how I was going to insulate the ceiling. Now it's time to do it and I realize I have a ventilation issue. It's a pole structure with metal roof and sides. The builder installed vinyl faced fiberglass. The purlins are 2x6.
How would you insulate this roof?
- Thread starter Boatman62
- Start date
readhead
Well-known member
It is insulated. Do you want more? Are you just trying to ventilate? I’m confused. Good looking place.
Yes more insulation. Both the lower and upper levels will be cooled and heated. What's up there now is basically ~R8 maybe R10. Would like to get between R30-38.
I'm a bit concerned about putting all that insulation up there with no ventilation in the roof structure.
The downstairs shop space will have a metal ceiling. The upstairs will have tongue and groove pine.
Marctrees
Well-known member
Contact your local office of Bay Insulation, send them phptp.
They will make recommendations... very fair pricing good folks.
Marc
http://www.bayinsulation.com/
Marc
They will make recommendations... very fair pricing good folks.
Marc
http://www.bayinsulation.com/
Marc
CombatNinja
Well-known member
- Joined
- Aug 24, 2013
- Messages
- 1,456
Is the roof a "hot deck" design? Meaning, no soffit vents? Zooming in on your picture, there might be a ridge vent?
bradpac
Well-known member
If you're going to keep the open stud bays. Either more vinyl back over what you have or spray foam it, either would be as fire resistant and durable as what you are currently working with. Being that the entire space is inside the insulated cavity, and you have doors that will let in some fresh air from time to time, I wouldn't worry about ventilation.
My Old Tools
Well-known member
50pascals
Well-known member
Spray foam.
Don't bother hanging fiberglass on the ceiling.
The metal will get enough airflow through the ribs and the existing fiberglass blanket that you won't have to worry about moisture buildup under the metal.
Don't bother hanging fiberglass on the ceiling.
The metal will get enough airflow through the ribs and the existing fiberglass blanket that you won't have to worry about moisture buildup under the metal.
I've had a couple spray foam contractors out here and the first thing they want to do is tear all the existing vinyl faced out. They say the foam won't adhere to the vinyl.
Here's a couple more pics. One showing the upper end of the roof as it meets the monitor. The other is the upstairs. The third is the soffit area.
Here's a couple more pics. One showing the upper end of the roof as it meets the monitor. The other is the upstairs. The third is the soffit area.
Attachments
There are no soffit vents at all on the lower level.
The upper level has vented soffits but are useless because the of the purlins. Only the first bay would ventilated. No ridge vent,,, same situation.
This will be finished interior. The lower roof will have metal and the upstairs will have tongue and groove pine.
The whole structure will have HVAC.
Soooo... here is idea I had. Yes it will be work.
1. Lag bolt 2x4 on edge to the existing 2x6 purlins.this will give me a 9" cavity.
2. Install R30 Rockwool
3. Sheet it with 3/4" foam
4. Install 1x furring
5 Install the finished ceilings. Metal lower level and t&g pine upper level.
This will get me ~R36. My concern is lack of ventilation. Maybe because the vinyl is already there it's not a concern???
1. Lag bolt 2x4 on edge to the existing 2x6 purlins.this will give me a 9" cavity.
2. Install R30 Rockwool
3. Sheet it with 3/4" foam
4. Install 1x furring
5 Install the finished ceilings. Metal lower level and t&g pine upper level.
This will get me ~R36. My concern is lack of ventilation. Maybe because the vinyl is already there it's not a concern???
My Old Tools
Well-known member
Where are you? It makes a difference.
rjacobs
Well-known member
XPS panels... R5 per inch.