Flat roof, joists resting on timer lintel. Sizing/Span chart

[cascas]

I am looking to build small extension wih a flat roof on the back of the garage.

The one end of the joists (2.8m long) will be on the brick wall, whilst the other will rest on a timber lintel. The lintel will need to span 4m.

Can anyone point me towards a span table for this for timber sizing?

 

[^woody^]

There aren't any for that use. You need to calculate a beam of timber or steel

 

[RonnyRaygun]

As Woody says, there aren't any tables for what you require.

Floor trimmers, yes. Purlins, yes, but not roof beams.

I can tell you that you need either a triple 47x220 C16 beam, or a double 47x245 C16.

However, if you intend to involve Building Control they will want to see calcs.

http://www.broxbourne.gov.uk/PDF/BC_TRADA_SPAN_TABLES _2008.PDF