Maintenance treatments for external timber

Maintenance treatments for external timber

Date Published

5 September 2022

Document Type




As timber is utilized in a wide range of external applications, there are many products and methods available that may be used for finishing surfaces to help protect against the elements and create an aesthetically pleasing appearance.

Different products have different service life expectancies, and require differing levels of maintenance. While this sheet provides guidance on the use and maintenance of timber finishes in external environments, it cannot, due to the huge range of products available on the market today, be specific about maintenance regimes. Manufacturers’ recommendations for maintenance intervals and application techniques should always be followed.

Key Information

Treated timber may be expected to weather in the same way as naturally durable untreated timber, and depending on the type of treatment, its performance and longevity may well be improved through the application of a finish.

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Case studies

Inn The Park is a new restaurant in St James’ Park, the oldest of London’s Royal Parks. The brief from the client, the Royal Parks Agency (RPA), was ‘to create a high quality and low-profile building which must nevertheless advertise its presence.’

Two radical timber buildings at the National Arboretum in Gloucestershire demonstrate how timber from trees felled in the routine maintenance of the estate were processed on site into structure and cladding, and constructed by volunteers and trainee carpenters.