Insulating attic and removing boards
While insulating the attic by foam airsealing and adding R30 rolls , I also removed some 1×6 boards which were nailed on top of the joists and were perpendicular-running the length of the attic. I wanted the insulation to sit as flat as possible.
Were these structurally important pieces?
I thought that they were used in the initial construction to stabilize the frameup, but now no longer necessary.
Replies
probably not
Maybe
is this stick framed?
Trusses?
Do you have strapping ?
What is the diagonal; bracing situation like up there?
When I was apprenticing, the carpenters put strong-backs on the attic joists, they were more or less 2x angles made with 2x6 and nailed to the joists. I think they were to keep the attic floor, and the ceiling underneath, even.
Other functions may have been to keep the joists from warping (should have been done with blocking or cross bracing) or just something to walk on. I had removed such 1x6 brace or flooring from old house attics before, but the spans were short and the wood bone dry. As a brace, 1x6 may have done its job, together with lathe and plaster, so if your joists are lacking blocks in the mid span, I would put the 1x6 back.
I would put them back.
They are either joist bridging or could just be something to walk on. Joist bridging braces the compression side (top side) of the ceiling joists from buckling sideways under load.
You can tell if they are bridging. If they were nailed at each joist, they are joist bridging. If they were just nailed at the ends, or in only a few places, they are just there to walk on.
The boards were there primarily to stabilize the joists until the drywall was installed. They're also often used by electricians to carry wires, but that's not their purpose. They are handy to walk on, but it's better to install an elevated catwalk if you need something.