What is weathering?
All wood is susceptible to weathering once exposed to UV rays from the sun or moisture from rainfall or the general climate.
'The weathered look' is really down to personal taste. Some customers like the driftwood-like appearance, however others prefer to keep their timber looking like new with a pigmented-finish.
There is a risk involved however when leaving wood exposed to the elements. During the weathering process wood can appear unsightly as the material can blacken due to moisture getting into the fibres and pulling out tannins and extractives. This can lead to patchy, inconsistent areas of discolouration which are unpleasant to the eye. While this can naturally weather to the silver-grey look over time, the process can take years until you're left with a consistent finish. It's this stage of the weathering process which has lead some town planners to reject the use of unfinished timber cladding, unaware that it is an easily avoidable and treatable issue.
What does weathering actually do?
During the weathering process, UV rays are impacting the polymer bonds within the wood substrate (cellulose, hemicelluloses and lignin). Lignin is especially prone to UV degradation and if not protected, the wood cells (mainly composed of cellulose) will become faded and loose, subsequently eroding the wood surface.
This issue is perpetuated by the common myth that cladding or decking can be left to weather naturally with no concern for aftercare or maintenance. The truth is that all timber needs to be protected to ensure longevity, consistent beauty and prolonged performance. We're a strong advocate of the use naturally decay resistant wood species such as Western Red Cedar Cladding or Siberian Larch, but to say it's fine to leave unprotected would be a disservice to our customers.
Fortunately there are a number of solutions that provide protection for timber while accelerating the silver-grey colouring process highly desired by many.
Get the weathered look
Sioo Wood Impregnation is a natural 2 part solution which accelerates the greying process for a beautiful, uniform appearance within weeks of application. Sioo crystallises deep within the wood structure, reinforcing the natural characteristics, providing a durable barrier against the elements. Sioo prevents moisture damage, leaching and offers UV protection against blackening of timber. Once fully applied, Sioo offers up to 10 years performance before a recoat may be necessary. Silva believe Sioo is the ideal solution for those looking for the weathered aesthetic while protecting their timber from the damaging effects of weathering.
Sansin Wood Sealer is another product which offers protection during the greying process. The water-borne penetrating sealer aggressively repels water while allowing wood to breathe. Over time, the wood will grey to a natural driftwood tone while retaining its water-repellency to protect against weathering and wood rot. Tests show that on average one application of Sansin Wood-Sealer reduces water absorptions by 84% and swelling by 72%. Sansin Wood Sealer also comes with the peace of mind of a 3 Year Limited Warranty (details upon request).