Is this timber pressure treated?

[Sard]

Hi, my builder has used this timber for the floating deck frame that sits on paving stones (no prolonged ground contact). However I couldn't see any treatment markings and I'm having doubts now.

Can anyone advise please?

 

[Wayners]

You have a C24 stamp so I read this is treated.
Look it up.

Id put a clear primer preserver on it next summer if you want extra protection

 

[freddiemercurystwin]

C24 timber is not typically treated. C24 is ordinarily used for structural work like joists etc, so no need to be treated normally. It doesn't look treated to me.

 

[big-all]

general comments

timber constantly getting wet then drying will last years without any treatment
the biggest problem is trapped moisture, about 20% so on ground as maximum danger with timber to timber next danger point with vertical lesser so but can still be a problem with build up off earth or leaves in shade and no sun exposure drying out the area

 

[Sard]

In my case it sits under hardwood deck boards that have 5mm gap, so very little exposure to the joists and absolutely no contact with the ground or organic material as the joists sit on pavers that were then covered with plastic membrane to sit between the joist and paver. I'm wondering though if the joists are not tanalised timber, whether I should take the boards off in the summer and coat the subframe with bitumen paint as I really want the deck to last for the next 20yrs and beyond.

 

[big-all]

i would say 8-12 years is a more realistic life with fully treated and maximum care taken
remember hardwood [balsa wood]just means it grows all year so not a real selling point unless its a hardy timber that can cope with wet and rot
life can be extended in the normal way with plank post and joist replacement as required to possibly extend life to perhaps15 years

 

[Sard]

Thanks, in my case I'm only referring to the joists as they seem to be untreated. The boards are bangkirai which has excellent wet and rot resistance capabilities