Although the buildings come fully treated, additional coats of wood preserver are required to maintain the building in top condition, and to meet the terms of the 5 year or 15 year guarantee. The first of which must be applied within two weeks of the building being erected, if the building is to be stored unassembled it must be protected from the weather until such time it has been erected and retreated.
Any good quality wood preserver e.g.., Cuprinol, Sadolin, preferably oil based as these offer better weather proofing than water based products.
Avoid home brands as these tend to be of a lower quality, and don’t offer good value in the long term. also with the quality brands you have a full range of colours, any colour can be used and does not affect your guarantee, NOTE “DO NOT RE-COAT THE FELT WITH WOOD PRESERVER AS IT WILL BE DAMAGED”