Finishing Oak- A users guide

We are constantly asked for our recommendations as to which finishing products will give the best results on our oak, both for kiln dried and green oak. Whilst there are clearly hundreds of different products to choose from, along with multiple ways of applying each product, there are a few that we always seem to come back to. These products and application methods will be explained in detail here, along with any alternatives you may wish to consider.

Internal Use

Finishing kiln dried oak boards

Fiddes Hard Wax Oil
Fiddes Hard Wax Oil

When looking to apply a finish to kiln dried oak, the first thing to consider is whether the boards are planed or not, as this will affect the appearance. For a planned board, we would always recommend 2 or 3 coats of Fiddes hard wax oil, either in clear or in one of the range of tints, depending on the finished colour you are trying to achieve.

It is important to note that even a clear oil will change the colour of the wood, wiping a damp cloth over the untreated timber will give a good preview of the colour change you can expect, but it is always best to test any new finish on a small area or an offcut first. If keeping the natural light tones of the oak is particularly important then Fiddes Oak Lightening Hard Wax Oil has been specially formulated to achieve just that effect.

For rough sawn boards, although hard wax oil can be used, we would normally recommend using a wax based product, such as Fiddes floor wax, as this will be easier to apply and achieve a more consistent result. Even if you are looking for a very rustic finish, some degree of sanding is normally wise, as rough sawn beams can be very sharp.

Finishing oak beams for internal use

oak beams sussex
A stack of fresh sawn oak beams

Oak beams are becoming more popular for use inside, mainly as fireplace beams. Whilst these beams can be treated in exactly the same way as kiln dried oak, this method will promote splits and cracks. If this is not the effect that you are after then it is advisable to slowly dry the oak beam, by keeping it in a dry, unheated, environment for at least a few months before installation.

Whilst the drying is happening the beam should be nourished with a regular application of wax, and this should continue every few months after the beam has been installed. Once the beam has been in place for around 6 months the majority of the movement should have occurred, at this point the beam can have a coat of hard wax oil, tung oil or linseed oil if a harder wearing finish is required.

 External Use

Finishing kiln dried oak boards

Although kiln dried oak is predominantly used internally there are exceptions to this, notably in doors and windows. These products certainly benefit from some sort of maintenance regime, normally carried out yearly, although in particularly exposed locations a 6 monthly schedule may be better.

This maintenance will normally comprise of a short rub down with 120 grit sandpaper, followed by an application of the finishing product that was originally used. In the case of all of our joinery products this will be Fiddes Exterior UV oil, and we would also recommend this product for any occasions where the original finish is unknown.

If you wish to colour your joinery then this product should always be applied prior to the application of the Exterior UV oil. Any of the stains will be suitable for external use.

Finishing oak beams for external usefiddes exterior high build wood oil

For the majority of external uses we would recommend that the oak beams are left unfinished. This is due to the fact that rough sawn timber does not finish particularly well, meaning that the maintenance requirements would become increasingly extensive as time goes on.

Having said this if you do particularly want to have a finish on an external product, in the case of furniture for example, then it is advisable to have the beams planed before installation. Once this has been done then the beams can be treated with Fiddes Exterior UV oil, as would be done with kiln dried.


We hope that this article has been of some help, and has answered any questions you may have about finishing oak and oak products. However if we have missed anything out, or you would like any more information then please don’t hesitate to contact us.

For more information on Fiddes range of wood finishes then please visit