The entrance to my basement has two joists that end over it and is supported by the rim joist and three 2x4s under the joists. The entrance is about 3 feet wide and with a concrete wall on one side of entrance and the foundation on the other side. The rim joist and the three 2x4s rest on the concrete wall and foundation. I would like to remove the 2x4s to gain a bit more height for the entrance and was wondering if the rim joist is strong enough, on its own(with joist hangers), to support the two joists that end over doorway.
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How tall is the rim joist?
The rim joist is 2x8 but it's the older dimensions so it's wider and thicker than today's 2x8 dimensions.
You're probably good, if there are no unusual loads overhead. It would be ideal to double up the rim joist, but that's a lot of work.
I'm thinking I will double up the rim joist. A bit of a pain, but better safe than sorry.
thanks.
Depends to some degree on how much roof load that particular wall carries. Plus the span of the floor joists that bear on it.
Not enough info to even come close to giving you an answer.
You gotta crib up the joists, cut them back, then slide the new piece in, getting 6" or so bearing on both ends. After that it's easy.
As said above, just be sure there's no big point load coming down on it. Can't tell you how many times a 3' beam started to fail because there's a 4-2X4 post above and resting on that is a 40' girder truss carrying half of the roof.
Also, another solution is to add a metal plate to the outside face od the rim joist. Sort of a modified flitch beam. Again, no idea as to loads, but a 1/8"x 8" plate, lag bolted so prevent seperation from the rim board under a load, wouldn't ad much to the thickness of the wall and you're not having to mess with the floor joists.
Doug
It's a header
Look at the requirements for a header on a 3' span in your building code for this span - you'll likely find that it requires (2) 2 x 8's or (2) 2 x 10's <eta, correction - (2) 2 x 4s or (2) 2 x 6s>. I don't see another way to look at it, so no, sorry, one 2 x 8 won't cut it.
Jeff
Building Codes (like the IRC) allow up to 4 foot spans for headers without them being 'doubled'.
So I don't agree with Jeff Clarke's advice on spans and sizes of the headers.
That said, I would not attempt to do any of the aforementioned structural alterations without a design professional's stamped and sealed plans and a permit issued by my local code office....or do so at my own peril...
Single headers
You may be thinking of R502.10 (2009 IRC) which allows a single header for openings in floor framing for openings less than 4'-0".
If you look at the header schedule (as mentioned) at R502.5(1) (again 2009 IRC) you'll find only double, triple and quadruple headers at exterior wall openings (see attached).
Jeff
Jeff
Doea one 2x12 equal the rating of a dbl 2x6 header?
Thanks
You answered my question. It is assumed that the rim is in place. So, if by chance there is a splice in the rim at that point in the wall you wish to open up, then I suppose the minimum header would not be appropriate, or you'd have to span the opening with another 2x member of equal ht as the rim-with proper support below.
And in a balloon framed wall, you couldn't just insert a properly sized header for a two story w/rim joist.
In the case of the original post-I'm going to assume again, that adding to the original rim, spanning across and bearing on that foundation/masonry wall, hanging any joists that run into that orig. rim with proper joist hangers, would work. Whether one or two more members needed to be added, you'd have to tell me.
thanks again.