Roof Timber Sizes Building Regs

For pitched roofs flat roofs and ceiling joists.

Roof timber sizes building regs.

Guidance on the sizing of timber floors and roofs for traditional house construction removed as the timber tables are now. Building control guidance note 18 purlin and rafter roofs timber sizes and construction details. Common joists sizes are 200 x 50mm 175 x 50mm and 150 x 50mm. Building control guidance note planning regulations created date.

All the figures are based on roofing tiles or slates laid on timber laths over sarking felt. The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. Ideally this should be done after the roof has been installed. All roof timbers including joists wall plates blocking strutting battens firings and noggings must be to be preservative treated unless the timber used is naturally durable.

Structural calculations for timber joists timber beams glulam beams flitch beams using the latest design codes. 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. Pitched roofs overview. The function of a roof is to protect the building below from the weather.

Building control guidance note domestic timber floor sizes and construction details. Domestic timber floor sizes and construction details keywords. Surveyors span tables for designing roof rafters. These things will affect the timing cost and overall running of your project.

In addition roofs must provide good thermal insulation and prevent the spread of fire from adjacent or adjoining properties. So whether your new flat roof is to be made of timber concrete or felt or a combination of these materials you need to comply with flat roof building regulations. Imposed loads roof snow load and short term point load altitude not exceeding 100m. When installing or repairing a flat roof you must adhere to building regulations.

Should refer to trada document span tables for solid timber members in floors ceilings and roofs excluding trussed rafter roofs for dwellings or ask your lbc surveyor for advice. Sizes of certain timber members in floors and roofs for dwellings. Building regs drawings specifications and guidance for building control. Building control guidance note 18 author.

Also the new sound insulation regulations restrict the building in of joists into party walls between. Pitched roof timber sizes. The building regulations 2010 isbn 978 1 85946 508 0 stock code 80581.