Ceiling Joist Size

Ceiling joist spans for common lumber species uninhabitable attics without storage live load 10 psf l δ 240 check sources for availability of lumber in lengths greater than 20 feet.

Ceiling joist size. There are several variables to consider when determining the proper rafter size. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. First step lets collect all the given information within the question.

Span exceeds 26 feet in length. It covers 2 common lumber species and sizes at 20 pounds per square foot load. Although 2 x 4 s are included in the official table they are not listed because it is never advised to use them.

Size length of ceiling joists standard size of joists. 12 inches species and grade. Sixteen inch oc spacing of ceiling joists made from 2 southern pine allows for a maximum 13 inch span length.

Usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below. This sizing guide for roof rafters will help determine what you need for your small project. This will support a room ceiling that is 10 feet long on one side as in 10 foot by 15 foot or 10 foot by 17 foot rooms which is a standard dimension for many rooms in residential construction.

For a joist to have the most strength it should stretch all the way across a room from the top of one. Use table r802 4 1 ceiling joist spacing. This is the distance between joist centres.

For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. For example the highlighted cell below shows that a 2 x 6 southern yellow pine joist with a grade of 2 and spaced 24 apart can have a maximum span of 10 feet 0 inches 10 0 if you are designing your structure to support a plaster ceiling. 1 inch 25 4 mm 1 foot 304 8 mm 1 pound per square foot 0 0479kpa.