Timber sizes on plans versus what’s used by joiner

[DC5]

Hi folks, 

we are about to start getting our kit put up and the frame is specd as 145x45 c16.

 

My merchant has offered two options one a 6x2 cls treated finished at 140x38mm the other described as reg and treated carcassing 47x150 finished 45x145.

 

I was just about to order the 140x38 but for some reason doubted it - both my joiner and architect are on holiday and need to order the timber so not sure what to do!

 

The rafters are stated as 170x45 and 195x45 so no idea what sizes that will equate to either!!

 

this is a Scottish build by the way.

[keith65]

I would use the regularised and treated C16 fin 47 x 145  these are based on 6x2 7x2 and 8x2 imperial sizes which have been planed down

[Temp]

44 minutes ago, DC5 said:

we are about to start getting our kit put up and the frame is specd as 145x45 c16.

 

Problem is you can get C16 that is

 

Nominally 145 x 45 but actually 140 x 43 after planing 

And

Nominally 150 x 47 or 150 x 50 but actually 145 x 45 or 145 x 47 after planing.

 

I suspect you want the latter, ideally with eased corners.

 

Are there any other clues on the drawings such as the thickness of insulation and or air gaps?