Hi, If I am adding a large bay window with a rough opening of 8ft in a load bearing first floor of a two story home can I use 2x12s for a header? I would using douglas fir. Any thoughts are appreciated. Thanks
Assuming it's a 2x4 stud wall, you'll have to put a piece of 1/2" plywood between the 2x12's to make up the right thickness. You may also want to use double king-studs on the ends. If you frame it in right and the load you mentioned isn't out of the ordinary, you should be OK.
Visit the Canadian Wood Council's web site and online design tool, SpanCalc.
How long has that been there?
I would use Pine, and make them 2x10. Is it an upstairs window?
This is a two story house. The bay window will be on the first floor and will need to support the second floor and the attic. I measured the width of the house in the basement and it is 24' I have already framed this window in after initially looking in a few books that say
2x12s > On 27 Jan 2007 06:44:18 -0800, snipped-for-privacy@optonline.net wrote: >
Long time. They have some useful tools; a worthwhile site to poke around.
R
I thought I knew the site. They bombard me with snailmail all year long.
For a while I thought about buying their structural design program to save engineering fees, but then I realized if it weren't for engineers, I wouldn't see anyone except clients, contractors, immediate family and hockey parents ; )
if your getting a permit, I would think/hope the town permit office will require an engineers seal not just a page from a book
good luck kickstart
If you are certain that (2) 2x12s will handle a 7'8" span in your situation, then a single 4x12 should handle an 8' span. The 4x12 is
3.5" wide, rather than 3" wide, so it has 7/6 the resistance to bending moment and deflection. 8'/7'8" = 24/23, and bending moment scales as the square of span while deflection scales as the cube of span. Since (24/23)^2 < (24/23)^3 < 7/6, the increased resistance of the 4x12 exceeds the increased load effects of increasing the span from 7'8" to 8'.Yours, Wayne
You're scaring me, Wayne. :)
For a second I thought Nick's influence had possessed you.
But good on those calcs!
cheers Bob
Just go to your local lumberyard an tell them your sitation and you are looking for a couple 8'LVL's. You can look on a site like TrusJoist
For reference, the span table above shows for a 24' wide building, snow area (115%), supporting a single floor above(40LL/12DL) and an attic, with a roof load of 40LL/15DL (highest) you would require a 3 1/2" x 9
1/4" Microllam/LVL. Many places stock 1 3/4" LVLs allowing you to gang them. This would mean you would need two 1 3/4" x 9 1/4" LVLs however you could simply go with a pair of 11 1/4" if you already have the opening framed for a 2 x 12.It would be best to just let your lumberyard or their distributor call out the beam therefore eliminating any guess work.
Mark
I would talk to an engineer or architect
My first thought is why you're using douglas fir other than its convenience in cutting and weight vs. yellow pine.
Hi, I had this sized for me and it came out to be a 2.0E Parallam PSL 3
1/2 x 11 1/4 which will fit in the existing framing. Two jack studs are needed on both ends. Anyone know the calcuation/code for king studs? I know it falls between 2 and 3 but do not have the code sheet. ThanksHomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.