hazchem wrote:
I have had a wooden shed on my allotment plot for about 5 years.
Someone told me that I should paint my shed with wood preserver. He is
a builder. He seemed to be going on the colour as it is faded and no
longer dark green all over. I would like to know if he is correct. How
often should you paint your shed with wood preserver?

There are, roughly speaking, 4 types of products on the market,
Creosote substitutes
Penetrating preservatives (e.g. Cuprinol Shed & Fence Preserver)
Water repellent paints (woolworths or B&Q "bargains")
Colour washes

Creosote substitutes probably need re-applying at 5 to 10 year
intervals, but loose colour over 3 to 5. Wear the right gear when
applying it.

Waxy penetrating preservatives probably need recovering every 3 to 5
years

Water repellent paints probably give protection for one or two years

Colour washes give no protection at all, and for appearance sake may
need redoing annually. Very dense colours appeal to TV makeover types.

The more you pay, the longer the stuff will last, and the more it will
protect you against. I last used the Cuprinol shed & fence preserver,
but at 16 quid per can it costs a lot to do a good job. You can get 3
times as much water repellent paint for half that money, from
woolworths or garden sections of big DIY stores.

Go look at www.cuprinol.co.uk for more info . Consider getting a
sprayable one, and the matching sprayer, for easier and better
application - some waxy materials will clog sprayers in minutes.

My local farm shop sells creosote substitute from these people:
http://www.bartoline.co.uk/msds.htm - Jolly good it is too.