I'm building a 20x30 single story with 10' side walls and I want to put a loft over the bedroom and bathroom area.
there will be a wall 14' away from the outside wall for the bathroom, what size floor joist and what spacing would work for this?
I will be using this area as a bedroom.
2x10 16 inch on center, #2 or better spruce.
This calculator is handy -
http://www.awc.org/calculators/span/calc/timbercalcstyle.asp (http://www.awc.org/calculators/span/calc/timbercalcstyle.asp)
It would tell you that a 2 by 10 would work for 24 in. spacing as well, but that is the limit. I usually feel better about going a notch or so above the minimum so I vote 16 in centers also.
Thank you
I didnt mention that the wall 14' away is not a load bearing wall just an interior wall.
the total span is 20' without the wall, can i still use a #2 df 2x10?
Not without turning it into a load bearing wall. The span is ~19' or you need to support that wall to the ground.
Thank you Don_p, what is normaly used for a loft in the 20x30 plans? I have the single story plans.
I know the floor joist are a 2x12 but i was looking at the head height lost, which is not that much I know.
if i use 2x12s for a loft do the need 16" o/c spacing or will 24 o/c be ok for a loft bedroom?
I don't have a plan.
It looks like you need #1 Dougfir or SYP 2x12's at that span or Select Struc SPF lumber at 16" on center.
If I understand your plan the lower floor girders are slightly inboard shortening their span as compared to this span from wall to wall.
Yes Don_P these joist would span over the top plate of the bathroom wall.
Thank you for the info for the 2x12
You can safely use the same floor joists that are called out for the main floor. They would have the same span. I show both high quality 2x12's and engineered I-joists.
Thank You John
is there a more decorative beam i could use for the loft, these beams will be exposed.
4x8?
I am using rough sawn 4 by 8's for my loft but I have a supporting wall at the halfway point (10 ft.). To span the whole distance I think (not sure though) you would need 4 by 12's. The beams I got were not graded so if you are dealing with inspections they would not be an option. Probably there are alternatives though.
20 ft. is a large span and a 4 by 12 or better that length will be very heavy!
Usually large beams are spaced farther apart and have heavier (2 by 6) decking which looks nicer
Thank You dug, That is what i would like to do is have larger o/c spacing and a hardwood floor on top.
What species are available to you in heavy timber?
Is there any way you can back up and make that midwall load bearing?
I've been planing 6x8x12' locust this morning... I don't feel real good at the moment.
Hey Don_P not a lot of options i have found so far other than #2 doug-fir around here.
QuoteIs there any way you can back up and make that midwall load bearing?
I second that thought. Seems like you might not be too far along to provide support for a load bearing wall there. It would be some work but might make things easier in the long run.
dug,in your opinion could i use deck blocks and an additional 2x12 built up beam just running the 10'8" under the bathroom wall? (20x30 single story plans)
i dont think i could dig at this point for a footer.
I got to thinking after I posted my comment, I would guess you would have to have footers on the supporting piers or else you may experience uneven shifting during a freeze.
It probably would be pretty difficult to do since you already have the joists (sheathing also?) down.
You may have to do a little research to find out what sort of beam would handle that span using the spacing you have planned (3 ft?).
I will probably just span the under 20' distance with 2x12x20' on 16" centers.
I do thank you for your help!
I'm going to say this very quietly, if there is no water there is no frost heave potential. I have cut the handle off of a shovel and dug where I couldn't turn over before. Makes for a long day but can be done. A shallower footing can be frost protected somewhat by covering it with foam insulation and earth.
A 4x12 #2 Dougfir with just under a 20' clear span and 30/10 psf load just squeeks by at 32" centers.
thanks Don_P