Basic Floor Joist Layout

Today i started laying the floor joists for our new house.

Basic floor joist layout.

Sits on top of sill plate. Header band joists connect the joists together. Ceiling joists are usually 2 by 6s or sometimes 2 by 4s if it is an older home. Before you begin cutting or measuring grab a pencil and paper and sketch an outline of your floor.

In simple terms the base case would be both stronger and cheaper. Joists are the horizontal members of the floor. Your sketch should depict the floor s basic shape and layout complete with any additional features like alcoves nooks and staircases. With lumber joists this is a fairly simple process as a contractor can simply look up the span tables included in the local building codes and go from there.

Floor joists are typically 2 by 8s 2 by 10s or 2 by 12s. A floor s framework is made up mostly of wooden joists that run parallel to one another at regular intervals. Subflooring is usually plywood. Residential structural design vertical structural forces we were about to start learning about floor joist span tables.

They wrap around the joists. With either i joists or floor trusses the joist must be designed by an engineering technologist based on the joist s span its dead load capacity depth thickness and in the case of. Continuing on from part 1. Like studs spaced out at equal distances.

For larger structures like floors roofs or decks try a fink truss design which has internal joists arranged in a w shape for extra support. Extremely long spans staircases or interior walls typically require additional support which can complicate your framing. Using floor joist span tables. Some newer homes have manufactured i beam shaped joists.

If you re trying to reinforce a shed or gable roof use a simple king post truss design which has a single vertical joist running through the center of the triangular frame. If we then compare that 2x8 layout with our base case 2x10s at 24 inch centers we find that although the smaller joists are cheaper we would need more of them because of the tighter spacing so the material cost would increase 17 and labor would be 44 higher.