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
Hi,
I have recently put up a log cabin in the garden and painted it with Sadolin superdec on the outside. I did this before realising that I ought to cover the whole exterior/interior with a preserver first.
Is there any preserver you know of that could be applied over the top of the sadolin and penetrate through?
I was advised that some solvent based preservatives may be suitable on top as they reactive the resins and pigment in the paint?
Or do you have any other solution that doesn’t involve stripping/sanding the paint back? Otherwise I will have to just preserver it internally and hope the best ?
Thank you
Adam
Reply to Adam Arthurs:
Hello Adam,
I am really sorry to say that you will not be able to apply a preserver now. They always need to be applied first, preservers penetrate into the wood to protect it. The Sadolin will be doing its job by preventing the preserver from soaking into the wood.
We have an interior preserver Cuprinol Five Star Wood Treatment (https://www.wood-finishes-direct.com/products/cuprinol-five-star-complete-wood-treatment) which is suitable for interior spaces, however this is not really going too make a lot of difference to the exterior wood in terms of protection.
I would recommend keeping and eye on the Sadolin to ensure its always in good condition, any wear or tear can be fixed quickly and then an occasional clean with Barrettine Mould and Mildew Cleaner (https://www.wood-finishes-direct.com/products/barrettine-fungicidal-wash-multicide) will help to reduce any damage to the wood caused by algae, or mould.
Hello
I’ve a few windows and doors to paint in Sadolin extra durable woodstain. They are in good condition but a couple of threshold steps have been worn bare.
I find that Sadolin have a preparatory wood preservative but only in 2.5 litres, which is far too much; I only require 500ml. Could you recommend a smaller and more affordable preservative that would suit as an alternative.
Many thanks.
Yrs Tony
Reply to Tony Pringle:
Hi Tony,
Thank you for getting in touch with your question. I would have to say it is always best if you are able to use products from the same brand, as they are designed to be used together with out any issues.
For a wax free alternative in a smaller size, you could have a look at the Barrettine Premier Universal Preserver (https://www.wood-finishes-direct.com/products/barrettine-premier-universal-preservative) this is a clear preserver that is likely to be suitable under the Sadolin, however I would have to recommend a test area first to be sure.
All the Best.
Hi, I need to re-preserve a wooden stable/garage block consisting of 4 stables, 2 garages and a tack room. The block is about 20 years old having been re-treated every 5 years with ‘old’ Cuprinol (the good stuf you cannot get anymore! :( ). What would you recommend as a re-treatment this year? I apply with a compressed air spray-gun.
Reply to David Caple:
Hello David,
Thank you for getting in touch with your question. One product you could take a look at is the Protek Stable Coat (https://www.wood-finishes-direct.com/products/protek-stable-coat) ideal for use on out door animal housing or storage areas. It is animal and plant friendly and easy to apply, for great protection.
I am not familiar with the Cuprinol product you are referring to, however if you take a look at this one to see if it might suit your needs and if you have any questions at all feel free to get in touch,
Hello Samantha,
From trees downed for one year I cut off 4 inch thick slabs, one red oak and one hard cherry, I have planed them flat and plan to use them to make end tables for around our fire pit. They are about 20 inches in diameter. They will reside outside. What product would you recommend to protect the wood? I want the natural wood look to be revealed. A light stain may be appropriate. Thanks for your help.
Reply to ROBERT WINBURN:
Hello Robert,
I love projects like this, keeps the feel of the garden space very natural. If the slabs have been inside for the last year then I would expect them to be on the way to being dry however, you may find they still need a little longer to reduce that moisture content. As a rough guide it takes around a year for 1 inch depth to dry. This is really dependant on many factors however, including storage, environment and wood type. If you have a moisture meter or can borrow one, I would measure the content first to see where you are at.
Ideally you want the moisture content to be 15% or below, any more than that and you can start to have problems with application, either straight away or fairly soon down the line.
When the wood is dry enough, then an oil is a good product to consider, it is micro porous and so any moisture that is still in the wood can disperse, you still need to wait for the percentage to be low enough however, there is a limit to how much moisture can naturally pass through the oil, the rest can get trapped under the surface and may cause mould or other problems in the future.
Oils will help maintain a natural appearance, are very moisture repellent and easy to apply, clean and maintain. I would recommend a couple of coats of the Barrettine Garden Furniture Oil (https://www.wood-finishes-direct.com/products/barrettine-garden-furniture-oil) over one or two coats of a preserver such as the Barrettine Universal Preserver (https://www.wood-finishes-direct.com/products/barrettine-premier-universal-preservative) which will help to reduce mould and decay.
I hope this help and do let me know if you have any further questions. We always love to see our customers projects and so feel free to share on any of our Social Media Pages or contact us.
Kind regards Samantha.
Hi. Can you advise, if the Barrettine wood preserver is safe (once dry) for use on untreated smooth pine furniture which will be used indoors?
Many thanks
Mandy
Reply to Mandy:
Good Afternoon Mandy,
Generally speaking exterior preservers, such as the Barrettine, are safe once fully dried, however its not ideal using them for interior project and they target things that are more likely to occur in an exterior environment.
There is and interior preserver from Cuprinol called Cuprinol 5 Star Complete Wood Treatment (https://www.wood-finishes-direct.com/products/cuprinol-five-star-complete-wood-treatment) and this would be more suited to the type of insects and issues that are common for interior wood and is well worth a look.