There are two basic methods of pitched roof construction.
Traditional cut roof dimensions.
Before trusses became popular nearly all roofs were cut on site from timbers lifted up one by one and secured in position by the carpenter.
Just keep in mind that if the length of the board size is more than 20 feet then you need to use a more expensive type of lvl board and not a traditional pine board for this longer length.
The roofing of dormers also varies with a roofs more popular than monopitch variants.
The timbers are often 400mm or so centres and vary in size according to span.
Roof pitch calculator results explained.
The seat rests on top of the wall that you re attaching the particular rafter to while the shoulder cut parallels the wall and allows several inches of each rafter to overhang the roof.
Traditional or cut roofs usually comprise a series of sloping timbers rafters fixed to a wall plate at their feet and a ridge board or possibly a wall plate at their head.
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.
50mm wide by 75mm 100mm or 125mm deep are all common.
Pitched roof construction.
The style consists of 2 sides with a ridge at the peak just like gable but each side actually consists of 2 different pitches.
Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run this is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.
When opting for monopitch the incline should not run back towards the main roof.
The picture makes it easier to understand than to explain.
A cut roof this is the traditional method of cutting the timber on site and building up the roof using rafters ridge boards joists and purlins etc the exact details being determined by the size of roof size of timbers etc.
Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge.
All the figures are based on roofing tiles or slates laid on timber laths over sarking felt.
Gambrel roofs are the traditional barn style roof.
Angle the angle of a roof is the same as the roof s slope except instead of being.
Surveyors span tables for designing roof rafters.
Traditional cut roof vs.
A horizontal cut called the seat cut and a vertical cut called a shoulder cut.
The overall construction of a traditional cut roof is to ensure that the load of the roof is evenly transmitted to the walls below.
The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction.
Pitched roof timber sizes.
The upper slope is low pitched and the lower slope is high pitched.
The rafters are the main load bearing elements of the roof.
