First you need to fix the roof, clean all the surfaces and make sure the windows and doors are sealed nice and tight. Then it's time to pick your wood preservation weapons! Check out our blog post about garden shed renovation and maintenance.
Exterior wood preservers are designed to protect garden sheds and other garden wood from biological threats such as mould, algae, wood rot and insect attack. Whilst many wood preservers do contain a small amount of wax, they generally only offer limited weather protection. We recommend that any exterior wood is treated with a preservative first then a suitable exterior wood oil. Decking oils such as Manns Premier UV Decking Oil or Ronseal Decking Oil are ideal for use on garden sheds.
Many but not all wood preservatives contain a small amount of wax or silicon to offer a degree of weather protection, this can be problematic if looking to paint the shed and especially with a water based exterior paint. Wax and silicon free preservers are available such as Barrettine Premier Universal Preservative and Sadolin Quick Drying Wood Preserver. These can be applied then painted over when fully dry.
Our advice on how to waterproof a shed, especially a new shed is to treat all exterior facing sides and panel edges with 2 coats of an exterior wood preservative, followed by 2 coats of an exterior wood oil prior to the shed being constructed.
Older sheds or sheds that have recently been constructed should first be cleaned with a wood cleaner such as Barrettine Mould and Mildew Cleaner. This is to remove and kill off any mould, mildew or algae spores that are either on the surface or in the surface of the wood fibres. once this has been done, treat all visible surfaces as above with 2 coats of an exterior wood preserver followed by 2 coats of an exterior wood oil suitable for sheds or a decking oil. This will provide an excellent weather protective finish that can be easily maintained year after year by simply applying a maintenance coat of wood oil.
Wood preservatives help to protect wood from mould, algae and insect attack but usually only offer limited weather protection. This means that it will need to be re-applied every year or two depending on the product used.
Our recommendation would be to first treat the shed with Barrettine Mould and Mildew Cleaner to ensure that any mould spores in the surface of the wood have been dealt with, then treat with a shed preservative of your choice.
To extend the life of the preservative and offer the structure better weather protection, we recommend the use of an exterior wood oil to seal in the preserver. The oil top-coat can then be replenished as and when required, usually every year or 2 depending on the amount of weathering that the shed is exposed to.
Black wood finishes on garden sheds are becoming popular as they provide a striking contrast against the green of grass, trees and other garden plants. Read more about achieving the perfect black wood finish in our blog.