How Much Will A 2x4 Roof Joist Support

Span calculator for wood joists and rafters also available for the android os.

How much will a 2x4 roof joist support.

They re designed to support your roof not your junk. Such calculations would hold if for instance the load is square. Here you can operate by assumptions that there is no wind or it is not as strong. How much weight can a 2x4 ceiling 16 on center hold.

But if you ask engineers what they do in their own garages you ll get a different answer. Such calculations would be valid if for example the load is quadratic. I used your formula backwards to calculate the max psf of a ceiling with 2x4 ceiling joists spanning 12 and spaced 24 o c. Here you can work on the assumption that there is no wind or the wind impact effect is not too strong.

If the bottom chord of a roof truss functions as a floor joist such as in an attic room it carries a live load that also varies by use but a typical live floor load for a residential space is about 40 pounds per square foot. You are correct in that a 1x would not provide much support for your roof s ridge line. An syp rafter can span 8. Assuming the fb of hemfir is maxxed at 1275 psi and i came up with 12 737 psf.

But i doubt this was the intention. So if your ceiling is unfinished you have some excess carrying. That a 4x8 sheet of 3 4 plywood with 2x6 joist on the edge and 2x4 joist in the middle can support. The fact that your ceiling joists span 15 feet and are only 2x4s and are holding up plaster and lath it makes more sense that the 1xs were trying to support the ceiling joists below.

It will make less sense to use 2 4. Ceiling joists of the first floor of a two story structure often serve as floor joists for the second floor. That seems like it would support a lot of dead load. Each ceiling joist is one 12 foot 2x4 turned on end and total answered by a verified structural engineer.

However if there is no strong wind measure 2 4 at least 8 feet can carry at least 1000 pounds vertically. Joist span tables use these tables to determine lengths sizes and spacing of ceiling joists. The horizontal bottom chords of most garage trusses are designed to carry the weight of drywall and insulation. Also available for the android os.

If there is no strong wind a 2x4 measuring at least 8 feet can support at least 1 000 pounds vertically. However it is highly advisable not to push the 2x4 material up to its limit. If you live in an area that requires a shed roof rafter to support a heavy load then an spf rafter can only span 7. How much weight can a 2 4 support vertically.