Roof Insulation systems for Timber Frame
JamesT
| Posted in Energy, Heating & Insulation on
G’Day;
Constructing a timber frame, and still have not finalized roofing system… oh boy…
Options:
1. Structural Insulated Panels (SIP’s)
2. Built-up roof system
- 2×6 T&G Pine decking screwed to horizontal purlins at 4 ft. centres
- 6 inches of polyisocyanrate foam – 4″ + 2″ cross piled to stager joints
- joints taped, edges foamed
- 2×4 furring strips on flat, screwed thru to rafters & purlins
- 3/4 T&G plywood top
- ice & water membrane
- standing seam steel roofing
Tentative plan is to go with a built-up system, due to SIP’s cost.
1. Looking for comments on Option 2 – Built-up roof system.
2. Looking for technical information on insulation options for the roofing system…
- polyisocyanurate
- polystyrene
- blown in celulose
- fibre batt
3. Primary concerns:
- insulation longevity of polyisocyanurate
- finding leaks in roof
Replies
What I'm using -
SIPS, 6" EPS, premade with T&G on inside, OSB outside, 3/4" furring strips and second layer of OSB, 30# felt, I&W shield, asphalt shingles. The air space created by the furring strips gives a "cold roof", good if you have snow and ice in your area. Otherwise, omit it.
Thank you.
That basically confirms my plan, and we need the airspace with minus 30 for two months in the winter...
Jim