My daughter and her husband just purchased a house built in early 60's with an attached garage. It looks like sometime in the 70s (guessing by age of wood), someone cut a joist, boxed and installed an attic access ladder. Then they decked with lap&gap.

The original joists are only 2x6 #2 and the span is 22' on 16" - obviously not a match, especially with a load. (Not only does it have the decking on top, it has 1/2 inch drywall - and the cut joist is already failing)

My plan is to remove all the drywall and decking. Use 2x10 #2 joists joined to the existing (non-failing) 2x6s. Then use double 2x10 joist (and box) for the ladder.

I don't recall what the term is for the center L-shaped 2x4 (bottom) and 2x10 that runs perpendicular to the joists, but that will go in as well.

The ceiling will again be drywall (but probably the 3/8 or 1/4 inch).

The question is, "Will this support decking and a some weight?" I looked at a book that put the 2x10 at 19'11" span, no weight, by itself, but will the joining of the existing 2x6 provide extra strength to handle this?

TIA,

 

I'm sure the Pro's will answer about the framing...but you may need to rethink the thickness of the sheetrock. Not only will it sag at those thicknesses (even with 16" spacing)....I believe code requires at least 1/2" and maybe even 5/8" to meet fire code.

 

@Gunguy45 - good points. I will check with city on fire code and as you suggest, 1/2 may be minimum for sagging.

 

Can't speak to fire code but typically 1/2" drywall is the minimum thickness for 16" on-center spacing.

There is lightweight drywall on the market now, I think you should investigate it.

 

How about the joist/load question? Is this the correct subgroup (Walls & Ceilings) to ask this question?

 

You're fine, you just need to wait for the pros in this area to quit working on other people's walls and ceilings