Timber for warm roof construction

[jimal1969]

Hi all,

I’m about to buy the carcassing timber for the joists for a warm flat roof, obviously all internal timbers.

I have noticed that the timber merchant stocks both treated timber carcassing and untreated timber carcassing all at the same price and all C24 grade. Am I right in thinking both will be ok but may as well get the treated stuff as the price is the same?

[nod]

Treated or untreated 

Neither will get any weather 

 

[Redbeard]

We-e-e-e-ll... (no, not Lulu, for those of a certain age) (explanation available on request)... OK, so pressure treatment is no longer CCA (Copper, Chrome and Arsenic) but whatever treatment is there may not be necessary in your circs.  My general feeling is that if you are not exposing timber to potentially aggressive conditions you don't need to treat it against them. My timber-framed extension will have no treated timber in, and neither have a few extensions and TF buildings which I have helped build over the last 15 years. I would not buy treated for mine even if it were available at the same price.

Edited July 3, 2022 by Redbeard
Checked facts re current formulations!

[jimal1969]

2 hours ago, Redbeard said:

We-e-e-e-ll... (no, not Lulu, for those of a certain age) (explanation available on request)... OK, so pressure treatment is no longer CCA (Copper, Chrome and Arsenic) but whatever treatment is there may not be necessary in your circs.  My general feeling is that if you are not exposing timber to potentially aggressive conditions you don't need to treat it against them. My timber-framed extension will have no treated timber in, and neither have a few extensions and TF buildings which I have helped build over the last 15 years. I would not buy treated for mine even if it were available at the same price.

Thanks for the response and yes please an explanation is required:)

but surely if treated and untreated is the same price, treated would be a better bet??

[Temp]

1 hour ago, jimal1969 said:

Thanks for the response and yes please an explanation is required:)

but surely if treated and untreated is the same price, treated would be a better bet??

 

I think some people worry about the chemicals used.

[jimal1969]

In the roof void!!??

[Temp]

5 minutes ago, jimal1969 said:

In the roof void!!??

 

It doesn't bother me but some worry about what's in insulation as well.

[Redbeard]

jimal1969: https://www.google.com/search?q=lulu+'shout'&oq=lulu+'shout'&aqs=chrome..69i57j0i22i30l9.6577j0j7&sourceid=chrome&ie=UTF-8#cobssid=s It was the w-ee-e-ll that did it.

''but surely if treated and untreated is the same price, treated would be a better bet??''

 

The feeling I have on timber treatment is that it contains stuff designed to kill things and if those things are very very unlikely to be there then it's a chemical I can keep out of the (or at least my, immediate) environment.

[Simplysimon]

3 hours ago, Redbeard said:

and if those things are very very unlikely to be there

bring in old furniture and bring in, possibly, woodworm.

[jimal1969]

3 hours ago, Redbeard said:

jimal1969: https://www.google.com/search?q=lulu+'shout'&oq=lulu+'shout'&aqs=chrome..69i57j0i22i30l9.6577j0j7&sourceid=chrome&ie=UTF-8#cobssid=s It was the w-ee-e-ll that did it.

''but surely if treated and untreated is the same price, treated would be a better bet??''

 

The feeling I have on timber treatment is that it contains stuff designed to kill things and if those things are very very unlikely to be there then it's a chemical I can keep out of the (or at least my, immediate) environment.

Can’t deny, if the timber is hidden by plasterboard and plaster it’s not going to do me any harm and there is that extra layer of protection for the wood, then I’ll take it