oak joists against pine

[Arthur]

Apart from cost. I mean for example, could 5x2 oak be used in place of 6x2 pine?

Thanks.

[dom]

If they're in a structural roll, calculations to show that the sections are suitable would have to be shown to your local building control officer. That would require timber tested and certified to an appropriate strength grade (usually C16 or C24 for softwoods - Dxx ratings for hardwoods). That's a simple matter for softwoods - all builders merchants can supply suitably machine tested joists. If you're considering a traditional oak timber frame in green oak, I believe the timbers are often visually strength graded (i.e. no machine testing) by somebody with the appropriate TRADA certificate.

In modern buildings, joists are usually concealed between ceiling and floor, one reason being for fire protection and the avoidance of collapse. Exposed joists would probably have to meet the minimum stanadards in some other way - possibly by being oversize, so that the

30/60/whatever minute rating was acheived by the predicted depth of charring leaving sufficient core timber.

But other than the caveats about strength ratings and fire protection (and cost), I don't think there's a problem.

[Arthur]

Thanks. I'm not really interested in oak for oaks sake as in the farm house look. I'm planning a loft conversion and I want to maximise the floor area of the conversion by minimising the extent to which the required joists will raise the floor level.

Arthur.

[The Natural Philosopher]

I stuck up exposed beams and the fire thing was never mentioned..

[The Natural Philosopher]

Steel?

[dom]

Part B Fire Protection, certainly covers structural collapse due to fire damage. In practice it comes down to what the individual BCO picks up on.

[meow2222]

The lowest profile floor is a solid wood floor, with no joists. 3"-4" total thickness is enough in many cases. The timber is all glued together to make one solid sheet.

Ask the right question!

NT