Carrying on from my last post, this post will cover the remainder of the framing details for the sunroom.
In my last post on the sunroom, I mentioned that the roof framing is all 2x8 joists - 24" o.c. spacing at one end and switching to 12" o.c. spacing over the longer span. The joists bear on the top plate of the 2x6 wall below and on hangers where they meet the 2x12 ledger. Because of the variable spacing of the joists, the 2x6 wall below was framed with a double top plate.
Once the joists were in, I added shims to the top of each joist to create a very shallow slope away from the house. Instead of using shims, I considered ripping 2x10s into "2x8"s with the slope built in, but there are a couple of big disadvantages to that approach; it would have cost more and measuring and marking each joist for the cut would have been tricky - any mistakes would have been costly.
To make the shims I built a jig by screwing down some 2x4s to some plywood, leaving enough space between the 2x4s to insert one pressure treated 2x2. I snapped a chalk line from one corner of the 2x2 to the approximate centre of the 2x2 at the other end, then ripped along the chalk line with my circular saw. The result was 16' of shim per 2x2 tapering from ~0" to ~1 1/2". Each new shim was then touched up with some brush-on preservative before installation.
Ensuring a consistent slope across all joists was easy using the shims - I started by measuring from the rim board back towards the house, then cut the shims as required to fit. To secure the shims to the joists, I used adhesive and a few brad nails to hold the shims straight while the adhesive cured.
After the shims were in, it was simply a matter of nailing down the pressure treated plywood sheathing. I hand nailed the sheathing over adhesive using 2 1/2" galvanized ardox nails, and I even put a few green deck screws in to boot - just to make sure everything would stay tight under the EPDM membrane.
Dirty Old Town - The Dubliners
| Image may be NSFW. Clik here to view.  |
| Looking east over the roof joists towards the leafless trees of the Slate River Valley in May. |
In my last post on the sunroom, I mentioned that the roof framing is all 2x8 joists - 24" o.c. spacing at one end and switching to 12" o.c. spacing over the longer span. The joists bear on the top plate of the 2x6 wall below and on hangers where they meet the 2x12 ledger. Because of the variable spacing of the joists, the 2x6 wall below was framed with a double top plate.
| Image may be NSFW. Clik here to view.  |
| Adding blocking between joists. The vent space between the top of the blocking and the underside of the sheathing will be screened before the ceiling assembly is closed in. |
Once the joists were in, I added shims to the top of each joist to create a very shallow slope away from the house. Instead of using shims, I considered ripping 2x10s into "2x8"s with the slope built in, but there are a couple of big disadvantages to that approach; it would have cost more and measuring and marking each joist for the cut would have been tricky - any mistakes would have been costly.
To make the shims I built a jig by screwing down some 2x4s to some plywood, leaving enough space between the 2x4s to insert one pressure treated 2x2. I snapped a chalk line from one corner of the 2x2 to the approximate centre of the 2x2 at the other end, then ripped along the chalk line with my circular saw. The result was 16' of shim per 2x2 tapering from ~0" to ~1 1/2". Each new shim was then touched up with some brush-on preservative before installation.
Ensuring a consistent slope across all joists was easy using the shims - I started by measuring from the rim board back towards the house, then cut the shims as required to fit. To secure the shims to the joists, I used adhesive and a few brad nails to hold the shims straight while the adhesive cured.
After the shims were in, it was simply a matter of nailing down the pressure treated plywood sheathing. I hand nailed the sheathing over adhesive using 2 1/2" galvanized ardox nails, and I even put a few green deck screws in to boot - just to make sure everything would stay tight under the EPDM membrane.
| Image may be NSFW. Clik here to view.  |
| Shims... |
| Image may be NSFW. Clik here to view.  |
| Ventilation gaps cut out from shims - for cross ventilation between joist bays. |
| Image may be NSFW. Clik here to view.  |
| This photo is supplementary to my last post - a shot of the conduit that feeds into the sunroom wall. Note that it still needs to be flashed for "air-tightness". |
Dirty Old Town - The Dubliners
