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 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.
A neglected garden shed that has been allowed to rot and decay.
In past years, treatments such as creosote and engine oil were used to preserve exterior timber, however, 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, today’s domestic wood preservers are safer for both the user and environment.
Types of Wood Preservative
Most wood preservatives nowadays are manufactured with similar ingredients due to the government-led restrictions, however the formulas and the strength of those ingredients do vary. In layman’s terms:
- Clear preservers help retain the natural appearance of the wood
- Coloured preservatives act as a dual-purpose treatment and stain that change the colour of the timber
- Solvent-based formulas have been around longer and are known for their penetrative properties
- Water-based treatments conform to strict VOC (Volatile Organic Compounds) regulations being imposed by UK, European and worldwide governments, making them safer for the environment
Why Use a Wood Preservative?
In short, wood preservers help extend the useful life of wood by preventing wood rot and decay caused by mould, algae, fungi and wood-boring insects. Interior and exterior wood that has been preserved, treated and maintained can last for many 100s if not 1000s of years, making it a very eco-positive option.
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 couple of years. Ideally, wood that has been treated with a preserver should also be treated with a suitable top coat such as a 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 preservers, here are just a few of our best selling products.
Barrettine Premier Wood Preserver
Barrettine Premier Wood Preservative offers microporous protection against wood rot, fungi, decay and mould as a deep penetrating solvent-based formula with wax and resin ingredients that help with water repellency. Due to this we only recommend using a solvent-based oil, varnish, stain or paint as a top coat if you wish, as water-based top coats will not adhere to the wax and resin base. Available in clear and an attractive range of wood tone colours.
Barrettine Wood Preserver for exterior timber – Ideal for garden sheds, fences and more.
Customer Review – Barrettine Premier Wood Preserver
The product is easy to apply, provided you don’t overload the brush and soaks into the wood. The boards on the house had two coats 3 years ago and still look good with little sign of green fungus (shady side). My neighbour has now decided to use it on his property.
Ronseal Total Wood Preservative
A highly penetrative, solvent-based formula, Ronseal Total Wood Preserver is perfect for use on all exterior timbers including garden sheds, fences, joists, doors and window frames.
Ronseal Total Wood Preserver – Available in clear and a range of colours for exterior wood
Customer Review – Ronseal Total Wood Preservative
Used for both my deck and my fence. Good coverage and easily applied using a brush. Natural colour which brings out the grain. Would recommend.
Cuprinol 5 Star Complete Wood Treatment
Available in clear only, Cuprinol 5 Star Complete Wood Treatment is a water-based, low odour and low VOC wood preserver specifically formulated for the treatment of interior timber. Deep penetrating formula ensures long lasting protection against insect attack, re-infestation and fungal decay.
Complete wood treatment for interior wood including floor boards, joists, joinery and more.
Customer Review – Cuprinol 5 Star Complete Wood Treatment
I ordered this product as I needed to apply a thin coating that got absorbed readily on old interior timbers and new Oak beams alike. Little evidence of any staining which was important. Applied via a spray nozzle and also a brush. Low odour and lasted a long time.
Osmo Wood Protector (4006)
A wood protective treatment that is free from biocides and preservatives. Osmo Wood Protector (4006) is 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.
Osmo Wood Protector 4006 – A biocide and preservative free wood protector, ideal for interior, high moisture environments.
Customer Review – Osmo Wood Protector (4006)
I can only say that I needed an undercoat to protect the bathroom wood door from steam, moisture and similar. So using the Osmo brand made sense before using Osmo oil.
Sadolin Quick Drying Wood Preserver
A clear water-based wood preserver suitable for new and bare timber, Sadolin Quick Drying Wood Preserver is 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.
Sadolin Quick Drying Wood Preserver – A wax free clear preserver.
Customer Review – Sadolin Quick Drying Wood Preserver
A great product that goes on easily. It’s protecting my log cabin even before I get round to getting the top coat on. Good preparation should result in a long life.
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 preservers. 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 themselves 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, call our experts on 01303 213808 to help with project advice and product recommendations.
We love to see before, during and after photos of any wood finishing project. If you would like to share your project pictures with us and our followers, you can either send us some photos or share on our Facebook or Instagram pages.
62 comments
My tongue and groove pine cladding on my summer house needs treated do I stain a colour first then apply a clear oil such as osmos or barratime? The front sees a lot of sun.
Thanks
Reply to Marc Elmes:
Hello Marc,
Great question, you do have a few options for this project. A coloured preserver and clear oil or a clear preserver and coloured oil. Both options will give great protection from the sun and also from the rain. Which to go for can simply be down to the colour you want to achieve.
For a clear preserver I often recommend the Barrettine Premier Universal Preserver (https://www.wood-finishes-direct.com/products/barrettine-premier-universal-preservative) because it does not contain wax it is great for what ever top coat you want to apply, oils, paints or stains. It is a clear preserver and so the colour can come from a product such as the Osmo Natural Oil Woodstain (https://www.wood-finishes-direct.com/products/osmo-wood-stain-protector) or alternatively a coloured Decking Oil, perhaps one of the Barrettine Decking Oils (https://www.wood-finishes-direct.com/products/barrettine-decking-oil) if there is a colour with in that range you like.
The darker the colour the better the UV protection, however even with a lighter colour the results will be good and the benefit of oils is they are easy to clean and maintain over time.
For a coloured preserver Barrettine Premier Wood Preserver (https://www.wood-finishes-direct.com/products/barrettine-premier-wood-preservative) followed by a clear oil such as the Barrettine Log Cabin Treatment (https://www.wood-finishes-direct.com/products/barrettine-log-cabin-treatment).
With the combination of two products you tend to get a better over all level of protection and its only the top coat of oil that will need maintaining for a few years, as long as you look after the finish.
If you want just a one product finish then the Premier Wood Preserver can be used as a stand alone product with 3 coats applied for the best protection.
Kind regards Samantha.
I have moved to a house with a wooden porch which is made of Idigbo timber, installed about 10 years ago. I don’t know how it has been maintained but looks in reasonable condition with no rot. What wood preservative and pre-treatment would you recommend I use? I would like to use a solvent based clear finish.
Reply to Alan:
Hello Alan,
Thank you for your question. Idigbo is a very durable wood in its own right, even with out a treatment applied. A hard wood resistant to decay and is quite stable over time with little movement.
If the wood currently appears to have no treatment applied then a preserver such as the Barrettine Premier Universal Preserver (https://www.wood-finishes-direct.com/products/barrettine-premier-universal-preservative) is a good place to start, this is a clear product that will help to prevent any decay or rot, it will darken the wood some, more if it is dry and silvered.
Then you could consider a clear oil, although many products claim they are not suitable for Idigbo, this is because it can often leach yellow when the wood becomes wet and can discolour or stain. However with the age of the wood I would expect you to be able to get an oil of some kind on there, and you could perhaps take a look at a Barrettine Teak Oil (https://www.wood-finishes-direct.com/products/barrettine-teak-oil) as an option, ideal for hard woods and very moisture resistant.
I hope that helps.
Hi what is the best and safe preserver for raised beds
Thanks
Reply to Pete:
Hello Pete,
Thank you for your question, I can reassure you that all preservers are safe once dry. When in their wet state they could damage plant life and be harmful to humans and animals if ingested, so care should be taken at the application stage. However once dry on the wood there is not risk to human, animal or plant life. The only real exception is aquatics, of which no products are recommended other than those specific to aquatic use.
I hope that helps and if you need any further advice or product recommendation please feel free to get in touch.
Hello. My son made me a wonderful garden seat from various wood including some pallet and decking pieces. It needs protecting before I put it in the garden but I have Multi Chemical Sensitivities and cannot cope with voc’s, even when they are just ‘lingering.’ I would hate to use something that would cause problems and result in my not being able to get near the chair!
I would appreciate some advice as to what might preserve this precious seat. TIA
Reply to Carron Hills-Harrop:
Hello Carron,
Thank you for getting in touch with your enquiry. Many and most products for the exterior will contain biocodes to help prevent mould. We often recommend a Preserver for exterior woods to help prevent rot and decay from occurring, these are likely to be unsuitable for you health wise.
So you are likely to need to skip this stage of protection, it will leave the wood slightly vulnerable, however a regular clean will make all the difference. To give the wood some protection against the weather a water based paint, may be the best option for you, these tend to be lower in VOC although they are not free of.
Ronseal Garden Paint (https://www.wood-finishes-direct.com/products/ronseal-garden-paint) is a great option to consider and has a lot of colour options and also Cuprinol Garden Shades (https://www.wood-finishes-direct.com/products/cuprinol-garden-shades) are probably the best to choose from. Both are available in sample sizes and so if you are unsure then perhaps see how you get on around the samples first.
I would say that once fully cured all products from our website are safe and so even if you went for something with a little higher VOC if you are able to treat and leave for a few weeks before using this may also help.
I can give no guarantees as to what will work best for you, those samples sizes could be a great help for you however and for more help and advice please feel free to get in touch.
Hi.
I’m doing some double garage doors, some cladding over the old window’s and along the side of the garage and a side gate too, I’m using new match tongue and groove board’s, can you please tell me what I need to get and do before I start please. The finished colour will most likely be a summer tan or similar!
Many thanks
Keith.
Reply to Keith:
Hello Keith,
Thank you for getting in touch with your question. It would be good to have a product or set of products that you can use for all these projects and I would recommend taking a look at a couple of options, both require a preserver and top coat and both will protect all areas of your wood.
For all exterior projects a preserver is recommended first, this helps to prevent mould, decay and rot in the wood. And you could take a look at the Barrettine Premier Protective Treatment (https://www.wood-finishes-direct.com/products/barrettine-premier-wood-protective-treatment) this is a bit like an all in one product that has some biocides in for preserving, and builds to a surface sealer for exterior wood, it is a cost effective option and can be topped up when needed.
And from Sadolin there is the Sadolin Quick Drying Preserver (https://www.wood-finishes-direct.com/products/sadolin-quick-drying-wood-preserver) followed by coat of the Sadolin Classic Wood Protection (https://www.wood-finishes-direct.com/products/sadolin-classic-wood-protection) and then one or two coats of the Sadolin Extra Durable Woodstain (https://www.wood-finishes-direct.com/products/sadolin-extra-durable-woodstain).
This will give longer lasting, better protection to your wood and with occasional care and maintenance can protect for many years to come.