Spacing For Interior Flat Roof Joist

If the roof is not completely square you can decrease the space between joists but never increase the space.

Spacing for interior flat roof joist.

Manufacturer of viperstud framerite studrite genieclip and joistrite. The tables below give maximum spans for rafters and beams. Ceilings and roofs excluding trussed rafter roofs for dwellings or ask your lbc surveyor for advice. Maximum clear span of flat roof joists in metres for sc3 timber spacing between joists size of roof joist 400mm 450mm 600mm 47 x 97 1 84 1 81 1 74 47 x 120 2 43 2 39 2 27 47 x 145 3 08 3 02 2 87 47 x 170 3 75 3 67 3 42.

Joists are traditionally made from timber. A roof joist is always spaced no more than 16 inches apart from another roof joist. Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope. We offer a complete line of cold formed steel framing products like metal stud framing rc channel metal floor joists metal lath and metal corner bead.

Joists are the parallel horizontal beams that run across an open space joining opposite walls in a building to support both the ceiling below and the floor above. Interior spaces that exceed standard sizes such as family rooms and garages require different dimensions in the size of the joist the joist spacing and the joist span. Boarding to be fastened on top of flat roof joists with a depth to width ratio greater than 4 the allowable clear spans have been calculated in accordance with bs 5268 2 2002 structural use of timber part 2. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.

Span calculator for wood joists and rafters also available for the. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. In these cases 2 inch by 10 inch lumber is often used for ceiling joists although trusses may be more practical. Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size.

The figures are based on quality materials. In other words you would space a roof joist 15 inches apart from another roof joist but never 17 inches apart. Measure from the ends. Spacing in exterior exposure.