Roof-rafters-and-ceiling-joists, in today’s professional roofers blog, we have chosen to go “beneath the shingles” a little to discuss some important structural terms that relate to your roof, but that you certainly won’t see on the outside of your home: roof joists, ceiling joists, rafters, and trusses.depending on the style and slope of your home roof, you will likely have one or two of these structural elements .... Joists and rafters are components used in the construction of buildings. understanding the difference between them is essential for those working in the construction trades, while basic knowledge is useful for homeowners if repair and maintenance issues arise., some demolition is done on the old ell to prepare it for renovation, while ceiling joists and roof rafters go up in the new section of the house..

Install rafters and ceiling joists with at least (≥) 1 ½ inches of the rafter or joist bearing on supporting wood members (such as a top plate or a valley rafter) and at least (≥) 3 inches of the rafter or joist bearing on masonry or concrete. 2. toe nail rafters to the top plate using at least (≥) two 16d nails. 3., joist spans for various sizes and species of wood. ceiling joists are used to support the ceiling surface materials. in a two story residential structure, the floor joists on the second level serve as framing for the ceiling on the first level..

Building codes direct that ceiling joists attach to -- rather than hang from -- either roof rafters or the top plates of exterior walls; three nails must be toenailed through the joist to secure it..., rafter boards: the boards creating the slope of the roof are wider than lumber used to build trusses – 2x8s, 2x10s and 2x12s are most common in rafters vs. 2x4s in trusses. rafter boards are fastened to the ridge board at the peak and the top plate where they join the wall. in finished space, insulation is placed between the rafter boards and drywall or other material is fastened to the face ....

Use the span tables below to determine allowable lengths of joists and rafters, based on size and standard design loads. you can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths., nonparallel ceiling joist designs require additional support construction in the ceiling. according to the international residential code (irc) from 2000, one of three methods may be used to maintain a continuous tie — support strength — across the rafters supporting the roof weight and outward pressure.