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
Dear Sir / Madam, I have just purchased a Victorian property that has timber-framed windows. The timber windows are about 20 years old. I have been advised by the surveyor that as the timber windows are constructed of hardwood and in fairly good condition, I should retain and maintain them as oppose to replacing them. However, there is slight damage to the 2 window sills due to condensation. Ideally, I would like to preserve them for as long as I can but which products would you propose. I am inclined to go for the Sadelin range. I can apply the Sadelin classic first; leave it for 16 hours before applying the Sadelin extra followed by a second coat of Sadelin extra after 16 hours. However, the wood surface needs to be cleaned beforehand. What can I used to clean the window frames so that any underlying microbial spores can be destroyed?
Although I’m thinking of using Sadelin as a wood preserver, I am open to suggestions. I look forward to hearing from you. Cheers.
Adam 0745 329 0002
Reply to Adam Cameron:
Hello Adam,
Thank you for getting in touch, although it sounds like you have everything in hand. The Sadolin range is a good option to go for with exterior projects. It is very durable and gives a really attractive finish. As you are considering the Sadolin Classic Wood Protection (https://www.wood-finishes-direct.com/products/sadolin-classic-wood-protection) and the Sadolin Extra Durable Woodstain (https://www.wood-finishes-direct.com/products/sadolin-extra-durable-woodstain) , it makes sense to stick with a Sadolin Quick Drying Preserver (https://www.wood-finishes-direct.com/products/sadolin-quick-drying-wood-preserver)
I would recommend a good clean with some Methylated Spirits before hand, this will degrease, remove any residue or natural oils in the wood and prep for better adhesion. Test areas are vital to ensure you are getting the desired result.
Hi,
I have a new shed, I thought it had been treated so I stained it. The rain came and soaked right through from outside to inside. Which product do you reccomend to keep the outside waterproof?
Thank you
Reply to Dawn:
Good Morning Dawn,
I am sorry to hear that you have had this issue. The structure of the shed, in itself, should keep any rain or moisture out, even before any product is applied and it is worrying that you have had this problem.
When you apply a wood finish product, it is purely to protect the wood and repel moisture from the wood, and so prevent mould and rot from damaging the wood. Paints, stains, varnishes and oils are not designed to seal the structure of the shed, and prevent water from getting in and I would perhaps get in touch with the shed manufacturer or supplier to see why this has happened.
I would also be happy to take a look at any photos you would like to send along with details of the product you have used to the contact us (https://www.wood-finishes-direct.com/pages/contact) page.
kind regards Samantha.
I have used Cuprinol clear water based wood preserver on some new garage doors.
Can I now use sadolin classic sprit based top coats?
Reply to Simon Beech:
Hello Simon,
If you have used the wax free preserver then yes you should have no issue with application of the Sadolin over the top. As with any advice, I always recommend that test area, to make sure not only that you like the result to be achieved but also that there is no adverse reaction.
All the Best Samantha.
I have an old Japanese cabinet that has been in storage for some time , dampness has affected the dry finish and affected the glue. I can stick the loose joints together and clean the carved ivory and mother of Pearl but need to treat the Wood. I used a wet cloth to remove the dirt but it has removed some of the old finish which was a brown colour I thought was teak. What would you suggest I should use to treat the Wood?
Reply to Rory Mackail:
Hello Rory,
This sound like quite a specialist piece. I would be happy to see if I can make some suggestions for you to consider, but I do think I need to see some images of the item and the current colours and condition, in order to make the best suggestions. You can email photos over to me and we can go from there.
Can you suggest a preserver/stain for Tanalised Gates made from soft wood. I’ve used Cuprinol Ducksback (5 year Guarantee) on a previous set of gates and was not impressed at all. These new gates (direct from manufacturer) are waiting for me to apply some sort of treatment before I fit ironwork and hang . Ideal colour would be Forest Green.
Reply to jaqor1:
Good Morning,
Exterior woods are so exposed to all the element and it can be difficult to give a long life protection even with the best products. Often we recommend oils as these penetrate the wood and will not peel and flake over time. They do not last as long as some other products, however a refresher coat can be applied to clean dry wood, when needed, with out the need to strip back to bare wood.
For a green exterior oil, you could have a look at the Holzol Weather Oil (https://www.wood-finishes-direct.com/collections/wood-oil) or you can achieve that colour by using a green preserver (https://www.wood-finishes-direct.com/products/barrettine-premier-wood-preservative) and then applying a green or clear top coal of the oil.
I hope that helps and for further advice please feel free to get in touch via our contact us (https://www.wood-finishes-direct.com/pages/contact) page
Kind regards Samantha.