4x2 joists - 100mm or 95mm any difference?

[Dhillon]

Hi,
Boarding my loft and ordered 4x2 joists from local builders merchants. I had 12 delivered at 4.2m lenghts. The joists are actually 95mm and have rounded (rebated edges?).

Is this normal or I should have been more specific when ordering? Are these decking joists as opposed to floor/roof joists?

The yard has closed for the day so I called another yard and they said joists are standardised so they are all the same?

The delivery note says 047x100 sawn kild dried treated.

If I can use them great otherwise I will have to send them back.

Any help appreciated.

 

[Dhillon]

Update - I think the joists are finished timbers, which would explain the missing 5mm. They should be rough sawn timbers which would probably be nearer 100mm.

Anyone?

 

[big-all]

yep the sizes quoted are the preworked sizes
sawn would come in at 102/51mm

 

[Dhillon]

Thanks, hopefully going to have them exchanged tomorrow.

 

[big-all]

i assume you are cross battening ??
you may have a problem as you have what you asked for as in its 4x2"
timber is alway referred to as its pre-worked size
if you want to be sure ask for the finished size as in "i would like the timber at the finished size off 100x50" but just make sure they don't have to work it otherwise there may be a cost and iff its a non stock finnish as in 102x51mm planed you will pay for 5x3 ripped down and planed
so iff you can use rough sawn 4x2 that may still come out as 99x51mm if its ripped down from 8x2 otherwise it will be 100mm[25.4x4=101.6 give or take 2mm]
but it should be cheaper than kiln died unless theres a restock cost

 

[Dhillon]

Hi big-all,
I was in Wickes today and so the timber I need. It was labelled 47x100 C16 Kiln - Dried Sawn Treated. Which is what I am looking for, to match the joists already in the loft.

Yes your right I may have a problem as I did ask for 4x2. Should not be a problem though, I could just use the regularised (eased edge) joists they delivered.

Yes I am cross battening at right angles over existing 4x2 joists. So using the regularised joists at 95mm will not be much different to the 100mm. I will still try to get them swapped though as I already have some lengths of 47x100. These will go to waste otherwise!

 

[big-all]

trouble with the sheds are timber is usually 3m or less

 

[Dhillon]

Ok after calling half a dozen timber yards I finally found one that does Sawn 4x2, not regularised so finished size is 100mm Seems like it is hard to get hold of these days. Being delivered in the morning.

The other lot is going back later today subject to a 20% re-stocking charge about £16. Rather that than trying to level out 95mm and 100mm joists.