I'm hoping to use 4x4 (nominal) wood beams as living room floor joists, but none of the online span tables/calculators seem to handle 4x lumber. Maybe an engineer type, carpenter, or internet sleuth can help me.
My clear span is 9'5", and I'd like the joist spacing to be no less than 16" o.c. Common lumber beams locally are Douglas fir and Spruce-Pine-Fir (SPF). I understand living room floors need to handle 40 psf live loads and 10 psf dead loads with L/360 deflection.
I'm willing to consider engineered wood beams and have seen 4x4 LVL, LSL, and PSL products. But those companies' span tables treat those beams as beams rather than floor joists. So, they aren't particularly helpful.
It's a tiny house on a trailer, so I want to keep the beam depth to no more than 3-1/2 inches (actual) to maximize headroom. These tiny houses are pretty much restricted to 13'6" in height (including trailer), so vertical space is at a premium.
The standard width of tiny houses on wheels is 8'6", and 4x4 SPF beams seem to cover their 7'10" clear span okay. However, from what I've been able to figure out so far, the extra 19" of clear span in our house rules out your typical 4x4 SPF or Douglas fir beams. Am I wrong? If not, then will any engineered 4x4 beams do the trick?
Another option I'm considering seems a little silly at first. Instead of laying a 4x6 SPF beam with the long edge vertical, I could lay the long edge horizontal. I realize that sacrifices lots of strength. Instead of being about 250% stronger than a 4x4 beam, it would be only about 150% stronger. But maybe that extra strength is all I need to get me the extra 19" of clear span while still preserving my 2 inches of additional headroom. What do you think?
Thanks in advance for any help you can offer.
My clear span is 9'5", and I'd like the joist spacing to be no less than 16" o.c. Common lumber beams locally are Douglas fir and Spruce-Pine-Fir (SPF). I understand living room floors need to handle 40 psf live loads and 10 psf dead loads with L/360 deflection.
I'm willing to consider engineered wood beams and have seen 4x4 LVL, LSL, and PSL products. But those companies' span tables treat those beams as beams rather than floor joists. So, they aren't particularly helpful.
It's a tiny house on a trailer, so I want to keep the beam depth to no more than 3-1/2 inches (actual) to maximize headroom. These tiny houses are pretty much restricted to 13'6" in height (including trailer), so vertical space is at a premium.
The standard width of tiny houses on wheels is 8'6", and 4x4 SPF beams seem to cover their 7'10" clear span okay. However, from what I've been able to figure out so far, the extra 19" of clear span in our house rules out your typical 4x4 SPF or Douglas fir beams. Am I wrong? If not, then will any engineered 4x4 beams do the trick?
Another option I'm considering seems a little silly at first. Instead of laying a 4x6 SPF beam with the long edge vertical, I could lay the long edge horizontal. I realize that sacrifices lots of strength. Instead of being about 250% stronger than a 4x4 beam, it would be only about 150% stronger. But maybe that extra strength is all I need to get me the extra 19" of clear span while still preserving my 2 inches of additional headroom. What do you think?
Thanks in advance for any help you can offer.