Thread: Cypress Pine

Hi Steve

White cypress pine has a durability rating of 1 for above ground use and 2 for in-ground use. I don't believe cypress pine has a 50 year lifespan rating for in-ground use.

My father-in-law's family business owns a cypress mill and supplied the cypress pine for my house frame. He advised me not to use it for in-ground use as it would likely rot over time. All the cypress posts for my house are mounted on galvanised stirrups set into concrete footings to ensure they are clear of the ground.

This may be one answer to your problem - cut off the posts just above ground level and bolt them to stirrups set into concrete footings, however this depends on what the posts are holding up.

The other alternative may be replacement with treated pine posts, These I believe have a lifespan of 30-40 years for in-ground use if installed according to specifications.

If your supplier recommended the use of the cypress posts in-ground for your particular application you may be better served by seeking an opinion from another professional experienced in the use of cypress pine for construction.

Regards
Dave
(Twosheds)

I concur. Callitris glaucophylla is meant to be termite resistant so maybe this is what is meant by "in ground use" but it aint fungal proof. Particularly if its in damp soil. As Twosheds said you would be better off conceiving a plan to get them out of the ground if it's possible.

Cypress has been used for many years as fence posts in arid dry country. Termites dont like it but wet ground will shorten its life.

seeing where you come from there is a very small chance that the cypress is macrocarpa.did you purchase the posts yourself,and was it from a known supplier?
i'm just wondering because there is alot of it available around your area

Thankyou all for your comments,
I have had the timber tested and it definetly is White Cypress,
They are saying that it is the sapwood that is decaying even knowing some post are decayed in the centre,
I am in disscussions with the supplier and they are going to send a rep out to have a look also,
Some of the posts are up to 2.5 metres in fill so replacement is an issue,
I think the solution in the end will be to cut off posts at ground level and pour a concrete footing say 600 wide by 600 deep the lenghth of the deck to pick up all posts and put them on stirips,
Thanks again for every one's input and any other idea are greatly appreciated,