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.
Roof dead load tables uk.
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.
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.
Typical design dead loads 2 table 1.
Click on a span to generate a full calculation you can adjust the exact span.
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.
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.
This span table is to the format and methodology given in bs 5268 7 2.
Uk site usa site.
Schedule of permanent loads commonly found in residential properties.
This should be compared to the table.
Dead loads kn m2 excluding self weight of joist 150.
For pitched roofs flat roofs and ceiling joists.
Standard loads of materials.
Pitched roof measured on slope clay tiles plain.
Dead loads kn m2 excluding self weight of joist more than 0 75 but not more 1 00 kn m2 2 40m.
To put this in context max permissible clear spans for joists for flat roofs with unlimited access imposed load 1 50 kn m2.
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.
These spans were calculated using our flat roof joist calculation.
The following table provides typical weights dead load self weight for various roofing materials where possible the values were taken directly from manufacturer technical data sheets and are the actual weights of specific representative products.
Arch 331 note set 13 1 s2014abn 2.
Typical design dead loads 3 dead load adjustments adjustments are made in the dis tribution of dead loads due to the placement of utility lines under the floor system and fixtures lightsfloor system and fixtures lights ducts etc on the floor ceiling which is the floor for the next story if.
Strength class c16 service class 1 or 2.
Find the column for your dead load and spacing and the row for your timber size to find the permissible clear span in metres.
