Mr Green wrote:
I am reseating a greenhouse on a concrete base - about 8ft x 6ft.

I will seat it on tanilized timber lats of say half inch x one and a
half inches - with rawl-bolts in the base - through the lats - and
then through the green-house base.


I am following the instructions which say that you should put wood
between the greenhouse and the base; indeed, the greenhouse sills are
not flat - they need putting on a wooden support - they would not rest
level straight on the base.

I did not think that tanilized timber will rot in a couple of years-
that is why I was planning to use it I thought that it would last
about ten years - is this incorrect?

If you are going to all this trouble why not do the job properly and use
hardwood. Go to a good timber merchant and see what they have. They may even
have some oak floorboards or the like that are sub standard and can be
bought for little more than tanilized pine. Still treat it before use and it
will outlast you.

Some 25 years ago I knocked up a gate for a chicken run out of the best
flat/thin pieces of oak from a load of slabwood sawmill waste bought as
firewood. I also repaired the chicken hut with oak from the same batch,
including 100% of the frame around the bottom. Only last month I visited the
present owners of the cottage (it has changed hands twice, and friends of my
son now own it) and was pleasantly surprised to see the same old chicken hut
and run, complete with my scrapwood gate still in use. I don't know about
other owners but I certainly never treated that wood in any way.

Mike