Everyone has heard of wood preservers but what are they, why are they so important and how do they work?
Although wood is an amazingly versatile and durable material, it can be susceptible to deterioration, especially so in environments where mould, algae, fungi and wood-boring insects are likely. The best way to protect and preserve wood, including timbers that have been tanalised or pressure-treated is to use a wood preservative.
In past years, sheds, fences, railway sleepers and other exterior wood were treated with creosote, engine oil or other preservatives that contained commercial grade biocides and insecticides. Over the decades, as a greater understanding of the toxic nature of these products became known, many were banned or restricted for commercial use only by strict government legislation. Thankfully, todays domestic wood preservers, although still toxic if misused, are generally safer for both the user and environment.
Types of wood preservative
Because of tightening legislation on the ingredients that can be used, most wood preservatives are now based on similar formulas. They may have slightly different formulations and ingredients, but they all work in a similar way to protect wood from environmental threats. From a user perspective the deciding factor usually comes down to whether a clear or coloured preservative is needed and if a water-based or solvent-based formula is preferred.
Clear preservers help to retain the natural appearance of the wood whilst coloured versions act as a dual-purpose wood preserver and stain. Most preservers were traditionally solvent-based but more and more manufacturers are changing these to water-based formulas to conform to strict V.O.C (Volatile Organic Compounds) regulations being imposed by UK, European and Worldwide governments.
Why use a wood preservative?
In short, wood preservers help to prevent many of the conditions that can cause the degradation and disintegration of wood over time. Using a wood preservative protects wood from mould, algae, fungi and wood boring insects, the most common causes of wood rot and decay. Wood that has been preserved, treated with a suitable top-coat and maintained will last for decades or longer.
How do wood preservers work?
The key ingredients of wood preservers are biocides and insecticides with the most commonly used being Permethrin. Permethrin is an insecticide in the pyrethroid family. Pyrethroids are synthetic chemicals that act like natural extracts from the chrysanthemum flower. Other common ingredients include Iodo propynyl Butylcarbamate and Tebuconazole. Most modern wood preservers are safe for humans, animals and plants when dry, meaning that they can be used on sheds, fences, wooden trellis, dog kennels, stables, joinery and more.
Are wood preservers an all-in-one solution?
Although wood preservers are great at protecting wood from biological threats, they only offer limited weather protection and direct contact durability. Some wood preservers contain a small amount of wax which means that rainwater will initially bead and run off treated wood. Surfaces treated with just a wood preservative however, will likely need re-coating every year or 2. Ideally, wood that has been treated with a preserver should also be treated with a suitable top coat such as an wood oil, wood paint or wood varnish. These top-coat products seal in the preserver and provide protection against weathering and wear from direct contact.
If overcoating a wood preservative with a water-based paint or varnish, it’s important to select a preserver that does not contain wax.
5 of our top selling wood preservers
Although we sell dozens of wood preservatives, here are just a few of our best selling products.
Barrettine Premier Wood Preserver
A solvent-based exterior wood preservative that offers microporous protection against wood rot, fungi, decay and mould. Available in clear and an attractive range of wood tone colours.
Customer Review – Barrettine Premier Wood Preserver
Ronseal Total Wood Preservative
A highly penetrative, solvent-based wood preserver for exterior timbers. Perfect for use on garden sheds, fences, joists, doors and window frames.
Customer Review – Ronseal Total Wood Preservative
Cuprinol 5 Star Complete Wood Treatment (WB)
A clear, water-based, all-in-one wood treatment for interior timber. Deep penetrating formula ensures effective treatment and lasting protection against insect attack, re-infestation and fungal decay.
Customer Review – Cuprinol 5 Star Complete Wood Treatment (WB)
Osmo Wood Protector (4006)
A wood protective treatment that is free from biocides and preservatives. Ideal for treating wood in high moisture areas, such as wet rooms, kitchens and bathrooms. Especially suitable for woods that are susceptible to blue stain, such as Pine.
Customer Review – Osmo Wood Protector (4006)
Sadolin Quick Drying Wood Preserver
A clear water-based wood preserver suitable for new and bare timber. Perfect as a pre-treatment before applying a wood stain, paint or other wood finish. Provides excellent protection for interior and exterior joinery against wood destroying fungi and blue stain.
Customer Review – Sadolin Quick Drying Wood Preserver
Top wood preserving tip!
All wood, new and old should be treated with a fungicidal wash or multicide wood cleaner before treating with a wood preserver. Why? Wood only needs to get wet or damp once for mould and algae spores to establish themselves in the wood grain. This can happen at any time in the transit or storage of the timber or the finished article including sheds, fences and decking boards. Although wood preservers will help to prevent mould, algae and fungi establishing itself on the wood, they are not always effective at killing off already established spores within the timber.
For this reason, we always recommend that all wood is initially treated with a fungicidal wash or mould and mildew cleaner to kill off any existing spores in the wood grain before applying a preserver.
Want to know even more about wood preservers?
For more information about wood preservers and their uses, contact our team of resident experts who are always on hand to help with project advice and product recommendations. Alternatively, see our wood preserver FAQ page which covers many of the most commonly asked questions about wood preservers.
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