Top Coat Treatment: Whilst Garden sheds, summerhouses and playhouses are supplied with a dip-treated base coat, the building will need a top coat treatment either prior to or immediately after assembly. Taking the top coat option this is a factory applied top coat added for you. The top coat treatment option is a golden brown finish applied to the external part of the building only you will still need to treat the internal part of the building as per the instructions. Once applied you will then need to treat the building annually with a water based treatment or in accordance with the instructions.