Skylight in 2x Roof Decking
Skylight in 2x Roof Decking
(OP)
Question I'm struggling with that I was hoping someone could assist that has run across it before. How do you typically frame a skylight in 2x roof decking with exposed dropped beams (like an eichler)? Typically, the decking and beam network is exposed so I don't see how you frame out the opening without introducing a bunch of ugly beams around the skylight (which is not usual from what I have seen). There is 4" of rigid insulation above the roof decking. Is it common to put the header framing above the decking around the skylight in the rigid insulation layer? Or is the decking typically just designed as a cantilever at the skylight (I haven't calced to see if this would work).
Just curious what others have seen so I don't come up with a totally unique detail for a relatively common problem.
Just curious what others have seen so I don't come up with a totally unique detail for a relatively common problem.






RE: Skylight in 2x Roof Decking
Mike McCann, PE, SE (WA)
RE: Skylight in 2x Roof Decking
Depending on the layup and span of the decking, you may not need headers. I have run across many of these without them and they have worked fine.
RE: Skylight in 2x Roof Decking
This takes a bit more work.
1. Run two supporting angles across the deck span, spanning from the main roof beams that support the decking.
The angles are placed between decks in routed/widened joints.
2. Angle leg would not extend below the deck surface so from below you don't see them.
3. Run two cross angles between the supporting angles - again - one leg flat and the other turned down.
4. In these cross angles install screws downward into the top of the cut-off deck ends.
5. The cross angles are welded to the supporting angles (in the shop probably).
6. The size of the angle you can use depends on the deck thickness - so for a 3" deck you can use a 2 1/2" angle.
This is a lot more work and money - getting the deck to support itself would be preferred.
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RE: Skylight in 2x Roof Decking
RE: Skylight in 2x Roof Decking
RE: Skylight in 2x Roof Decking