Understanding the natural characteristics of timber and what to do if you feel there is an issue

At Zest we are committed to the environment and we are very proud to be a Forest Stewardship Council® Certified company. (FSC® C114990) and all timber used has been ethically sourced from responsibly managed forests. To find out more about how we care for the planet, visit our environmental page.

Although the majority our products come with a 10-year guarantee against rot, we recommend that you follow timber care measures to ensure your product lasts for many years to come.

Download Timber Care Information Sheet

Splits and cracks

Splits & cracks are to be expected in timber and they naturally appear in the grain due to changing temperatures and humidity levels. They are not a cause for concern as they will not affect the strength or durability of the product.

If a particular split or crack becomes visible and is of concern simply use the “2p Coin Test” as a guide. There is no need for concern if the coin will not fit. If the coin does fit in the split, potentially there may be an issue. In this case, in order for customer services to investigate the matter fully, it should be reported in writing to your retailer, along with a clear photograph showing the 2p coin in place.

Sun bleaching (from packaging) and green spotting

Sun Bleaching (from packaging) & Green Spotting (Caused by pressure treatment) are not causes for concern and they will fade over time when items are placed outdoors. Neither will affect the durability of the product.


Knots are a natural characteristic of timber however a dead knot may be an issue which can be reported in writing to your retailer and must include photographic evidence to support the query.


Ideally, we advise you to wait 6 months before applying any further treatments or painting the wood. During this time, the pressure treated wood will dry from within its core. If you wish to treat or paint your product, at a later stage, any paint or treatment specifically for timber is preferred.

Treating your wood

Important: Pressure Treated products should not have any further treatment applied for the first 6 months.

Timber Care Product Sheet

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