Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.
Roof dead load tables uk.
Steelbeamcalculator co uk has a shopper approved rating of 4 7 5 based on 1184 ratings and reviews.
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.
This should be compared to the table.
You need to measure the complete span of your floor joists together with the distance between them the centres and the size of the timbers.
3 3 dead loads dead loads consist of the permanent construction material loads comprising the roof floor wall and foundation systems including claddings finishes and fixed equipment.
Flat roof with no permanent access and altitude not exceeding 100m 0 75 kn m udl 0 9 kn point load most areas exceeding 100m but not exceeding 200m excluding parts of scotland pennines north east england refer to bs 6399 3 1 kn m udl 0 9 kn point load.
Standard loads of materials.
Dead loads kn m2 excluding self weight of joist 150.
The values for dead loads in table 3 2 are for commonly used materials and constructions in light frame residential buildings.
Schedule of permanent loads commonly found in residential properties.
Strength class c16 service class 1 or 2.
Dead loads kn m2 excluding self weight of joist more than 0 75 but not more 1 00 kn.
Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.
This table is for a dead load of more than 0 25 but not more than 0 50 and allows for an imposed loading of no more than 1 5 kn sq m.
The dead load on a roof is the weight of the roof structure itself along with any permanently attached materials or structures on the roof so it must be designed first of all to.
For pitched roofs flat roofs and ceiling joists.
Pitched roof measured on slope clay tiles plain.
D dead load l live load l r live roof load w wind load s snow load e earthquake load r rainwater load or ice water load t effect of material temperature h hydraulic loads from soil f hydraulic loads from fluids.
Not more than 0 50 kn m2 3 27m.
Surveyors span tables for designing roof rafters.