# Attic stairs - Sistering joists?

• posted on December 3, 2006, 7:46 pm

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: http://www.memphisfoldingstairs.com/instructions.htm
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.
My problem....I can't get a 14' joist up into the attic.
My question: -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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• posted on December 3, 2006, 10:20 pm
Need clarification: "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)."
This hall is in the second story of the house above the garage. Is that right? And is cannot be made to transfer a load to the foundation because it's just some framing and drywall secured to the subfloor and the ceiling joists. Is that correct?
Let's say that the left side of the RO can transfer weight via the adjacent LB wall. The right side of the RO just rests on some framing that's over the open space in the garage, so it could sag down the ceiling of the garage. I have 3 ideas:
1. Down. Does not work to have a post in the middle of the garage. 2. Across. Probably not much shorter to put a strongback over the NLB wall. 3. Up. Connecting to the roof framing may put a depression into the roof decking.
What are your other options to locate the disappearing stairs other than over the garage? I know that halls are preferred.

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• posted on December 4, 2006, 12:09 pm
Tom- thanks for the reply. You are 100% correct in your assumptions. And that's exactly the problem I foresaw, the POTENTIAL sagging of the garage ceiling, which I doubt would EVER happen from the amount of weight being put on it by 1/2 of an aluminum pull-down ladder, but then again, building codes are building codes and I'm about as anal as they get.
First, RO & LB?
1. Down -> I already have 2 posts in the garage to bear the load of that one interior wall, may eventually one day convert garage into livable space, so, no more posts :-) 2. Across -> Correct, not much shorter...one guy at another forum suggested putting up the 8' and 6', letting their ends butt up, then securing them together with another 8' beam glued & lag screwed together, to make it like a single piece, with the ideal solution being to instead connect them with a 1/4" steel flitch lag bolted in a staggered pattern... 3. Up -> Correct, I'd rather have to one day jack up the garage ceiling and repair, rather than repair any roof damage in a worse case scenario
Hallway is preferred since I already have a scuttle hole there. Every other room is a bedroom, kitchen, diningroom, or livingroom where it would be unsightly and I'd get whipped by my wife.
Any other ideas? If no, just the abbreviation clarification :-). I can try & break out my pythagorean theorem and see if I get somehow get a 2x6 14' long into the attic through the scuttle hole or through a 54" hole since I need to rough-cut that anyway for the opening. I have 8' ceilings, the attic is about 4' high before I'd hit a rafter, and at the diagonal, a rafter is about 6' from the scuttle opening....I may be able to squeeze it in....now comes the question of fitting it in my camry, is it illegal to drive with the trunk open and about 6' of wood sticking out? Otherwise about 8' sticking out a sunroof?
@yahoo.com says...

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• posted on December 4, 2006, 12:51 pm
Andy writes: Here's an off the wall suggestion , not knowing the exact layout.
Build a triangular truss in the attic which rests between two load bearing walls and use it the way #3 solution was proposed -- to stabilize the joist from above.....
Such a truss would not be as high as the attic ceiling and would be a simple triangle, but I don't know the layout or if the idea is even practical....
Just an idea.
Andy

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• posted on December 4, 2006, 1:56 pm
RO - Rough Opening LB - Load-bearing
First of all, a 14' 2x6 laid on its side will curve quite a bit, so avoid any pieces with knots to do the following:
Transport: put a few blankets on the roof of the car. Lay the board on the 5.5" face centered on the roof and centered on the length of the vehicle. Front rope connects each end of the front bumper to the end of the board. Rear rope connects each end of the read bumper to that end of the board. Drive home slowly and no quick turns. Attic insertion - With a helper in the attic, cover the far end of the RO with plastic in the attic, add a little plastic on the ceiling side of the near end of the RO to help the board slide. Use a 14' piece of string to see how it's going to work. Helper will bow down the leading end of the 2x6 as it enters the attic to avoid the rafters. Good luck.

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• posted on December 4, 2006, 3:28 pm
G wrote:

You are making a very basic error in your assumptions. The doubled joist is not there just to support the fold down stairs. It will be supporting the entire load that will be placed anywhere in the attic above the joists you cut off.
Yes, you can make a built up joist. Takes more than one thickness, really requires 3 (minimum) unless you make it a much larger (in depth) one. You fasten a series of shorter 2x framing lumber staggering the joints. I have done it. If your joists are 2x8 (say), the first run would be a 6 & 8 laid end to end. Next would be three pieces cut so you overlap the joint in the first one by a good margine (minimum 2ft offset but more is better). 3rd layer is back to 6 & 8 but laid opposite of the first one. Even better is to sandwich 3/8 or 1/2" ply between each layer. Of course it also requires that you make liberal use of construction adhesive and nail the p*** out of it.
Harry K

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• posted on December 4, 2006, 3:33 pm
Harry K wrote:

Ooops. 2nd layer doesn't have to be 3 pieces. It can by two as long as you can make a good lap on all three layers.
I was thinking of the one we built for my neighbor - 30 ft long supporting the middle of a garage floor. Had the same problem of getting long sticks into the basement.
Harry K

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• posted on December 4, 2006, 4:21 pm
Got it, basically sandwich the 8' and 6' joint (where the ends meet) with two additional, figure about 4' long, 2x6's (same size), and liquid nail and then 16d nail the crapload out of it from both sides.
Thanks for correcting my error, now that I understand it will be supporting anything I store up there (and me when I walk around up there to store things on the plywood floor I'll be laying down up there above the insulation), I will make SURE to get either the 14' up there with the excellent suggestions from Tom (thanks!), or build one up with your suggestions. Thanks again!!!

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• posted on December 4, 2006, 5:22 pm

There's no windows, skylights, or gable vents in the attic?