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Attic Stairs - Sistering joists?

16 years ago

So I need to install my attic stairs in a frame running PERPENDICULAR to the attic joists (not parallel which is the easier way). So I'll be cutting through 2 joists.

If you look here:

Read Step #2, specifically the last sentence which refers to Figure 3 (that's basically what I need to do), where it states "The double joist sections shown in Figure 3 must be long enough to be supported by a load bearing wall at both ends."

Here's my issue, the stairs will be installed in the middle of a hallway, lined by 2 walls. Only ONE of those interior walls is load bearing (supported by beams in the garage). The other wall is non-load bearing (nothing supports it in the garage). So the only way I can make the doubled up joists long enough to reach TWO load bearing walls is to make it go ALL the way to the edge of the house so it reached an exterior wall (that would be the 2nd load-bearing wall). That requires a 14' joist.


I can't get a 14' joist up into the attic.


-Is it possible to construct a 14' joist by somehow joining an 8' and a 6' joist? How? Assume that there is no way to support the 14' joist except at the far ends of it, which will be resting on load-bearing walls...

Of course, I may just say this is all way overkill since I'm only using a folding aluminum staircase which really doesn't weigh much (compared to the heavier wooden version) and I can probably get away with doubling up the joists but just having it span two walls where only ONE is load-bearing, and the other is just a regular non-load bearing interior wall.

Any opinions on this?

(After all, my neighbor has a wooden one and he didn't double-up anything, and he's been using it for 15 years...)

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