Which joists?

[Faye C-Davis]

Hi all. We are having an double extension and the architect has stipulated that the floor joists need to be 63 x 170mm C24. The length will be just over 4m. Spaced at 400mm over a 10m space.
I am really struggling to find this specific size of timber anywhere.
I have been looking at the option of open/metal web joists but have not yet gone as far as getting a quote.
Does anyone have any experience with anything I have written? If so any advice would be greatly appreciated

Thanks,

Faye

 

[freddiemercurystwin]

Just use slightly larger joists that are readily available.

 

[foxhole]

Architects should have stipulated "or equivalent" they seems to have little knowledge of stock timber sizes.

 

[Mr Chibs]

The figures you have are probably what you've been given, from the Trada tables (span tables).
63x170 c24 gives a span of 4.19 Metres @ 400 centres.
With 75x170 c24 timber this span would be 4.43M, so this should be suitable and easy to find.

47x195 = 4.36m
These are in the 0.25 to .50 dead load column