Hey Everyone
Got a question I am thinking about building a garage 24 x 24 putting in insulation as well as drywall on the ceiling and light storage upstairs. I picked up a plan I like in the plan it uses 2×10 12″ on center with solid blocking every 8 feet it also has a knee walls upstairs tieing the roof to the ceiling. Now my question is will I run into any problems spanning 24 feet with 2x10s will it support the load. Also I live in the northeast and do have snow loads. Thanks for any info
Replies
24 feet with 2x10s
To clarify, are you talking about the floor joists here?
yes I am talking about the floor joists my roof rafters will be 2x12s 16 on center
"yes I am talking about the floor joists my roof rafters will be 2x12s 16 on center"Since you said floor joists and not ceiling joists there's no way you can clear span 2x10's 24' without a girder mid span or using I-joists that are the proper size to clear span 24' which you can use without a girder mid span. If your talking just ceiling joists then you can use 2x10's 24'.Joe Carola
Thank you Joe maybe I miss spoke it is the ceiling joists I was questioning thank you all for the information
no john ... you didn't misspeak... they are floor joists.... a ceiling joist supports only a ceiling.. no floor load above..
if you use the center stick ( beam ) or the i-joists.. either way you will not need 1-2x12 rafters @ 16" oc....
you can use 2x8's @ 16"
the design you are looking at is trying to make a truss out of the rafters the knee walls and the floor joists
it will work.. but you won't get it by a building inspector without a PE calling our all of the calcs and connections..
IE.... each set of rafters will be tied by the "kneewall " (hangers ) to the corresponding set of joists below... it means that your flooring will not be continuous
the "kneewall " hangers will go thru and get nailed to the side of each rafter and each joist..
if you are going to do that ... you might as well have it framed with attic trusses designed for a 40# load
and you have to design in a stairwell thru the trussesMike Smith Rhode Island : Design / Build / Repair / Restore
We used 24 and 26ft 2x10s as rafters. They were finger-jointed though.You'd might want to compare price vs. TJIs as those 2x10s will be steep.
I didn't do it....the buck does NOT stop here.
Hello John:If you have the 2x10 floor joists at 12" OC and the 2x12 rafters at 16" OC -- then the vertical struts in the knee wall wouldn't work...Things to do to stiffen the floor:Your struts/knee wall studs should be clinch nailed at the top (to the side of the rafter) and you'll need a gusset of some sort on the side -- I'd use some 5/8" or 3/4" plywood triangles. (Remember the joists are on one side of the rafter, and the strut is on the same side -- so it is in the same plane as the joist...)Put good collar ties at least 32" OC (2x8's?), and a 24' 2x12 ridge (or an LVL?)Glue and screw the 3/4" plywood storage floor, and if things still are too bouncy, then you could sister some 14-16' 2x4/6's onto the bottom edges of the joists, to form a bottom chord. These would be best to span between the struts.Or, you could just use some I-joists...or a steel beam at mid span, though obviously that makes two 9' doors the best/only option. :-)my 2p,
Neil
First, if you can find nice 24' 2x10's, let me know. I know they exist, but don't like what I've seen. (ASSUMING THE 2X10'S ARE CEILING JOISTS--) Why not trusses? A lot less time spent in framing and everything else. Why the kneewall if it is just for storage?
in the plan it showed it as a way to tie the roof and second floor I assume for strength and possibly to stiffen up the floor
that's a pretty springy floor
2x10 @ 12" oc .. assuming you can get #1 ( bet you can't ) and they're Hem-Fir , they'll have a modulus of Elasticity of 1.3
a 30# / design load will limit them to 18'6"...
you'd have to go to 2x12 @ 12" oc with an "E" of 1.6 in order to span 24' and it would still be a 30# load
i'd run a center beam with one lally column.... now your spans are ony 12' for the joists... 2x8 @ 16" oc
one lally column is really not that big a deal...unless you have teen-age drivers
are you going to do one door or two ?
mike no teenage drivers and one large door and one scary wife when she's behind the wheel
john... personally i like two 9' doors... they'e harder to do now with the shear wall requirements
but with two doors , the lally column becomes mootMike Smith Rhode Island : Design / Build / Repair / Restore
Why not run a glue-lam down the middle and hang the 2x10's of the glu-lam. He would only be spaning 12' with the joists. The right size glu-lam can span 24'.
I did a garage where the ceiling was bowed pretty bad and the owner wanted light storage above. Garage was 12x24 with 2x4's running the length with sheetrock and plaster on it. Sagged 4" in the middle.
I ripped it all out and installed a double 2x10 across the garage and ran 2x8's from the beam to the top plates. Worked out well. Ceiling is flat and he got that big car top carrier off the floor.
More info please.....from the plan!
"Knee wall" as in ballon framed or as in platform framed?
How is the roof to be framed?
Is there a center beam and post in the ground floor?
Can you buy 2x10-24'? and what species of timber?
There is no "light storage" ...plan for a minimum of 50 psf load.
The span sounds very "iffy to me" given the limited data!
.........Iron Helix
knee wall as in platform the roof will be 2x12 16 oc and no center beam