How Much Will A 2x4 Roof Joist 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.

How much will a 2x4 roof joist support. How much weight can a 2x4 ceiling 16 on center hold. Here you can work on the assumption that there is no wind or the wind impact effect is not too strong. However if there is no strong wind measure 2 4 at least 8 feet can carry at least 1000 pounds vertically. Such calculations would hold if for instance the load is square.

If there is no strong wind a 2x4 measuring at least 8 feet can support at least 1 000 pounds vertically. Also available for the android os. Span calculator for wood joists and rafters also available for the android os. I used your formula backwards to calculate the max psf of a ceiling with 2x4 ceiling joists spanning 12 and spaced 24 o c.

Assuming the fb of hemfir is maxxed at 1275 psi and i came up with 12 737 psf. That seems like it would support a lot of dead load. So if your ceiling is unfinished you have some excess carrying. They re designed to support your roof not your junk.

But if you ask engineers what they do in their own garages you ll get a different answer. An syp rafter can span 8. You are correct in that a 1x would not provide much support for your roof s ridge line. Joist span tables use these tables to determine lengths sizes and spacing of ceiling joists.

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. 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. How much weight can a 2 4 support vertically. That a 4x8 sheet of 3 4 plywood with 2x6 joist on the edge and 2x4 joist in the middle can support.

If this is the case with your structure use the floor joist table to determine maximum joist length load. Such calculations would be valid if for example the load is quadratic. But i doubt this was the intention. The horizontal bottom chords of most garage trusses are designed to carry the weight of drywall and insulation.

Ceiling joists of the first floor of a two story structure often serve as floor joists for the second floor. Would 2x4s be adequate ceiling joists for ceilings with drywall and insulation. While the heavy load span specs for a 2 4 rafter are much less than a light load they would allow you to have a shed width of over 14 with a gable roof. Each ceiling joist is one 12 foot 2x4 turned on end and total answered by a verified structural engineer.