Roof Timber Sizes

Surveyors span tables for designing roof rafters.

Roof timber sizes. Pitched roof timber sizes. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. The imposed load should be calculated in accordance with bs 6399 part 3 1988 code of practice for imposed roof loads as a rule of thumb for altitudes not exceeding 100m you can use a uniformly distributed load of 0 75 kn m and for most other areas exceeding 100m but not exceeding 200m you can use 1 kn m for parts of scotland pennines north east england and heights over 200m you will need to refer to bs 6399 part 3. It s often chosen as the standard timber for roof extensions or joist refurbishment as it s the most cost effective internal structural timber.

Here the number is 1166 66 inches. Your choice of batten size here will be determined by the weight and span of your metal roof panels. Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings. If the extension length is half the extension length the 2 hips will meet at the existing wall and the roof will come to a peak with no ridge like half a pyramid.

Rough timber is probably the most popular timber in construction we stock both native imported rough timber so we have all you need buy online and collect at one of our 7 branches nationwide or choose home delivery. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. Plasterboard on the underside of the rafter. Outside of the u s a degree angle is typically used.

It is often compared to slope but is not exactly the same. For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches. Timber battens for metal roofs come in a range of sizes. The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction.

C16 timber is commonly used in floor and roof joists for internal building work. This is the distance between rafter centres. Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall. C16 timber is kiln dried timber certified to comply with the criteria of strength grade c16.

Here the number is 941 86 inches. For pitched roofs flat roofs and ceiling joists.