Hardwood Decking Preservation is vitally important to prolong the life of your wooden deck. In addition to protecting your timber from the elements you can also make the decking look stunning too.
Exterior timber decking is attacked by two forces. Rain and moisture penetrate the timber and encourage the growth of fungus spores – the start of rot. Ultraviolet (UV) light from sunlight damages wood fibres, clear finishes – pretty much everything in fact.
The techniques we describe below are equally applicable to hardwood or softwood decking, though cost may preclude it’s choice for softwood decks. They evolved from our marine customers with teak boat decks, and some of the techniques used to prolong the life of these expensive assets. Timber boat decks have to be grippy when wet. A boat is used in all weathers, and a slippery surface just isn’t suitable. This clearly precludes any painted or varnished finish on the deck itself.
Typically boat decks are constructed of high grade teak. Teak carries a lot of oils which give it great resistance to water. Over time, and with exposure to sunlight and water, the oils in the teak will get damaged or washed away, and the fibres of the wood themselves get bleached (silvered). We have a multitude of marine customers who use the hardwood decking preservation technique described below to extend the life of their teak boat decks.
The article is illustrated with a set of photographs provided by one of our customers who has a large iroko deck in Scotland.
We have also started a demonstration hardwood project. We expose this to the elements in Kent all year round. It demonstrates aging and maintenance requirements of this finish.
I don’t have a boat – I do have hardwood decking to preserve
Long life decking starts below the deck
Before you build the deck, or have someone build it for you, make sure you get your design right. Protecting a set of deck boards with a rotten superstructure is no use whatsoever however. Please read this article which shows you how to avoid the common design pitfalls for timber decking: Build decking that will last longer. Long life decking is never an accident.
The deck boards – hardwood decking preservation
There is no such thing as a no maintenance clear finish for timber. If you want to show it off – you will have to maintain it. Varnish requires maintenance coats, and is a time consuming job to apply. If you let the finish fail – you WILL be sanding back to bare wood and starting again. This article will show you how to varnish properly and maintain that finish,.
Sacrificial Sealing with CPES
An alternative to varnishing decking
Varnishing timber is hard work, and requires maintenance. Varnished poorly or not maintained properly you will need to sand back to bare and start again.
A customer of ours, Vicky, had this beautiful Iroko hardwood deck which had a varnish finish that had failed very early in life. Click the images to see full details, back button to return.
As this was the second time that the varnish finish had failed on Vicky’s hardwood decking, each one necessitating massive expense sanding and refinishing, she sought advice on hardwood decking preservation from us.
Vicky’s hardwood deck had suffered damage from the failed varnish finishes. There is clear evidence of silvering from the joint effects of water and UV light from the sun.
Sacrificial Sealing
We call this hardwood decking preservation technique ‘Sacrificial Sealing’. We know that the sealer is destroyed by the UV light that it is exposed to over time. UV light destroys it from the outside of the timber first. UV light attacks the CPES in the outermost fibres first. The UV light then silvers those same external wood fibres after it has attacked the CPES. The underlying CPES sealed fibres however still offer protection to the timber, keeping water at bay and controlling moisture levels.
When required, but typically each year before the weather turns wet, another coat (or two if required) of Smiths Clear Penetrating Epoxy Sealer is applied. This treatment will fill the silvered wood fibres, and restore the colour of the timber, as well as restoring full weather proofing to the hardwood decking. Hardwood decking preservation is remarkably simple when done this way. Before reapplying CPES you do not have to sand. Application of CPES for hardwood decking preservation merely requires cleaning, to avoid sealing dirt in.
You can see how to do this technique, and how much maintenance it will require, in our epoxy sealed wood for exterior use article.
Hardwood Decking Preservation by Sacrificial Sealing
Benefits
- Secure to walk on when wet as it’s not a gloss finish
- A more natural looking finish than a varnished finish
- Much simpler application than varnishing
- Much simpler maintenance than varnish
Disadvantages
- Cost – Smiths CPES is not a cheap product
- There will inevitably be silvering of the outer fibres of your decking with this technique. A properly varnished and maintained hardwood deck will not suffer this effect
The Look of the Preserved Hardwood Decking
With many thanks to Vicky for the photographs of her stunning deck. What a beautiful living space she has created.
Maintenance of Preserved Hardwood Outdoors
Vicky’s decking is in Scotland, and we are reliant on her for these fabulous pictures and the maintenance of her decking.
As a result we have started a project to maintain epoxy sealed wood outdoors in Kent, and to report on the maintenance and aging of it over time. Click the link to see how epoxy sealed wood ages over time.