We would choose pressure-treated timber when the budget allows. It is the better starting point if you want fewer preservative-treatment jobs. Choose dip-treated timber to keep the initial price down when you are happy to follow its regular treatment schedule.
Separate protection, appearance and weathering
Record what the factory treatment covers. Then record any stain, paint or water-repellent finish you want to apply. Check the guarantee separately from the paint colour: anti-rot cover usually has a narrower job than the whole building.
A real example of the conditions
Forest's guarantee requires annual retreatment of its dip-treated products, excludes direct ground or water contact for them, and requires suitable treatment of cut pressure-treated timber. Installation instructions and proof of purchase also matter. These are Forest's conditions; use your chosen manufacturer's own version. Read Forest’s guarantee conditions.
Forest's separate care advice discusses cut ends and compatible finishes. Where a general care page and a model's instructions appear different, ask the supplier which requirement applies to your order. Keep the written answer. Read the care guidance.
Price the maintenance you can actually do
- Find the treatment instructions before ordering.
- Check whether all required faces remain accessible once installed.
- Record initial work and the stated retreatment interval.
- Include the right products, equipment and labour in your comparison.
Do not invent a ten-year cost from an assumed annual tin of treatment. The area, product coverage, number of coats and permitted application conditions need to come from the chosen system. A written maintenance plan is more useful than a guessed lifetime saving.
Keep a simple record
Save the receipt, product code, installation instructions and treatment dates together. Photograph the completed base and any work that the supplier asks you to document. This makes future care and a possible guarantee enquiry easier.
Your next step
Sources and method
- Forest Garden guarantee conditions · checked 2026-09-19
- Forest Garden product care · checked 2026-09-19