loft help please

[slamin81]

guys I'm building a loft in my pole, barn it older, size is 30x40 I am going to do a loft on one side 15x40, my question is with it going to be 15ft across should I use 2x10 or 2x12s and how far apart, my apologies if there is a post already, I done a short search with no results.. thanks amos

 

[GMCGarage]

guys I'm building a loft in my pole, barn it older, size is 30x40 I am going to do a loft on one side 15x40, my question is with it going to be 15ft across should I use 2x10 or 2x12s and how far apart, my apologies if there is a post already, I done a short search with no results.. thanks amos

It depends on the load you want to support. Best bet is 100 psf LL, which is generally a storage load

2x12's, 100psf, max span is 14'-10" for #1 Southern pine, 12" o.c.
2x10's, 100psf, max span is 12'-6" for #1 Southern pine, 12" o.c.

Thats based on L/360 deflection too, so max deflection would be 1/2" for the 2x12. That might be a bit extreme. Maybe could go down to L/240.

That should give you some insight on how to proceed.

 

[DividedAttention]

I used this site last fall when building a heat-able room in my Morton pole barn. The top of my room serves as a storage loft.
My span was 14' and I went with 2x10's on 16" centers.
http://www.awc.org/codes-standards/calculators-software/spancalc

 

[The Tool Tyrant]

guys I'm building a loft in my pole, barn it older, size is 30x40 I am going to do a loft on one side 15x40, my question is with it going to be 15ft across should I use 2x10 or 2x12s and how far apart, my apologies if there is a post already, I done a short search with no results.. thanks amos

Here's a link that should be of help... http://www.wclib.org/pdfs/simpspantbls.pdf

 

[cj7jeep81]

I also used the awc.org link to calculate joists. I'm building a similar sized loft, roughly 15.5'x40' I'm using 2x12' SYP on 16" center. Using that calculator, the max span for the numbers I used was 16' 1". I'm using doubled up 2x12's as the beam at the back, and a framed 2x6 wall at the front, so my true span is really about 15' (3" bearing at the front and rear). I used 50psf live load, 20psf dead, and L/480 deflection.

 

[GMCGarage]

I also used the awc.org link to calculate joists. I'm building a similar sized loft, roughly 15.5'x40' I'm using 2x12' SYP on 16" center. Using that calculator, the max span for the numbers I used was 16' 1". I'm using doubled up 2x12's as the beam at the back, and a framed 2x6 wall at the front, so my true span is really about 15' (3" bearing at the front and rear). I used 50psf live load, 20psf dead, and L/480 deflection.

Good point, take into account the span of the beams at the front and back, they are collecting 7.5' tributary width of the loft.

What span for those were you looking at? At 100psf, 2-2x12 are good for about a 10' span.

 

[cj7jeep81]

16'1" span, but not using 100psf for the load. Using 50psf live, and 20psf dead. I'm not planning on storing engine blocks up there. My uses will be an office/gunsmithing/reloading room, and an open storage/TV/card table room. So very little will be actually going up there.

 

[GMCGarage]

16'1" span, but not using 100psf for the load. Using 50psf live, and 20psf dead. I'm not planning on storing engine blocks up there. My uses will be an office/gunsmithing/reloading room, and an open storage/TV/card table room. So very little will be actually going up there.

I would then use 2x12 @ 16. Will be a stiffer floor. Dont forget some blocking too in the joists.

 

[cj7jeep81]

Like I mentioned in my first post, I am using 2x12 SYP on 16" centers

Will definitely use blocking as well.

 

[slamin81]

Thanks guys for the responses, its main use will be light storage, the reason for building the loft is under,it I'm wanting to section it off and make a smaller are that I can box in and have nice area to do car detailing and different stuff.