Hi All,
I am currently designing a Cape Cod style home. The span from front exterior wall to rear exterior wall is 36 feet with the parallel interior load bearing wall is approx 18 feet from front and back. My questions is about the floor joists I will need. Can I use conventional 2×12 joists or should I use and engineered I-joist.
Thanks in advance!
Jay
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Replies
If you're doing your own design to the point of specifying floor joists, then I assume you're drawing your own plans. If this is the case, I suggest you educate yourself about construction methods and access the library for some residential construction information.
One resource that I rely on when I'm designing or drafting working drawings is a current building code manual. The CABO code book or the Uniform Building Code book will provide the answer to your floor joist question....and a lot more.
Kinda hard to give structural advice without a lot more info. Like local codes, loading requirements, etc. But a few thoughts come to mind.
No way should 2X12s span 18'. (In my opinion) I-joists can comfortably do it, depending on the depth, manufacturer, spacing, and series of I-joists.
But what concerns me is the other framing. If it's a cape cod style, that means story and a half. What holds up the 2nd floor? What holds up the roof?
You need someone to design a framing system that can actually see your blueprint, and is familiar with your local situation. No way can we do that here. Everything from the roof down needs to be dealt with.
Yesterday I went fishing with dotted line. I caught every other fish.
just did one like that, 2x12's almost 20', but these were 12"o.c., blocking helped a lot, but, it fills the cieling up with wood, if you try to line up recessed lights on windows, cabinets, fireplace, etc, hahaha.
no turn left unstoned
Check with your local building department. Ours has a four page xeroxed handout full of spans and nailing schedules and all sorts of useful info. Stick to what's in the handout, and they're happy. For anything beyond, they require an engineer's wet stamp.
-- J.S.
I don't know how your lumber is but here it is ####. Go with I Joists. Longer spans and a lot better floor.
According to the UBC table 25-U-J-I you could do it at 16" OC if you used #1 Douglas Fir, you could span up to 19'11"
This is standard wood frame construction and you would not need engineering like with trussjoists (ie:cheaper)
You'd only need to block this in the middle once but twice would be better
Edited 8/22/2002 10:05:35 AM ET by EXLRRP
Edited 8/23/2002 9:01:23 AM ET by EXLRRP