Garage Guide

How do you strengthen ceiling joists in a garage to support overhead storage?

Exist gable roof with 2x8 rafters 16" oc. 2x10 joists 16" oc -24' span.

Public Comments

1. We build an "L" on top of joist to strenghten them think of the verticile part of the L as a 2x8 and the bottom part of the L a 2x6 nail the 2x6 to the top of the joist and then nail a 2x8 to the side of the 2x6 breaking the joints. This will keep the ceiling strong and very straight, you would not believe it, it simple but will work, trust me
2. It Sounds plenty strong for storing junk. If you were going to suspend a car or something, you might need to beef it up. Look at the construction of the floors you walk on in your house. It is very similar, and those floors can hold a grand Piano, or a water bed.
3. With 2x10 ceiling joist on 16 centers , I wouldn't think you would need to strengthing them unless your planning a LOT of weight. If thats the case I would install a beam.
4. For spans as wide as 24 feet, I always split the difference with an appropriately sized structural beam (like a glu-lam). 24 feet is a significant span. The easiest solution would be to install a beam underneath the joists. Really, more information would be needed.
5. 24' spam of 2x10 it has allowable uniform loads for approximately MAXIMUM 5 lbs/sf .This zone is when you secured and support joists with two 4x4 one on top and one in bottom of the joists on two side of storage (if use hanging storage) . If using attic as storage a sheet of ply wood nail or screw to joist and divide weight all cross of the sheet.
6. To be honest, you may want to ask this in the engineering section under science and math. You need to provide a bit more information. First, the design load. The load criteria for living space is usually 40 psf live load, 10 psf dead load. Psf is pounds per square foot. But this is unfinished storage so the design load will be lower. The other thing is the depth. The span of the 2x10's is 24' 16"oc, right. But if you use a beam to split the distance of 24', then you need to know the length of the beam. If you sister more lumber on the 2x10's, that isn't necessary. The other thing is a beam even possible. If the beam were to end over the overhead garage door, will it interfere with the door operation? Then you are stuck with adding 2x10's. This could be sister 2x10's on or adding them so it is 2x10's 8" oc. Or you may find that the design criteria for unfinished storage is low enough that you only need to deck with 3/4" To put some perspective on it, at 40 psf live load, 10 psf dead load, a 2x10 can span 16'. You can call the local inspector and see what the design criteria for unfinished storage is. Also the local lumberyard can size the lumber, whether adding 2x10's or splitting the span with a beam, like a LVL. This may help: http://www.raisedfloorliving.com/spantables-1.shtml Span tables for various loads, spacing, spans. Another practical point, are the walls and ceiling finished. The beam will be probably be cheaper either way, but getting joists up there will be difficult. And with a beam you need to have solid bearing, meaning it needs to sit on studs that run to the bottom plate.