Finishing oak windows and doors

[Flyfisher]

We're having oak windows and door in our west-facing kitchen extension and are proposing to leave them untreated externally so that they naturally weather to a silver/grey finish.

Internally, I'm thinking of a simple wax finish and was intending to use a liquid beeswax, probably Liberon. However, I've read that this is not ideal for 'wet' areas such as kitchens and bathrooms. The kitchen area itself is quite large (about 3.5 x 8m with a very high ceiling) so I'm wondering if high humidity is likely to be an issue in practice, but of course I won't know until we start using the space and I want to have the windows and door finish applied before then.

Should I be considering other sorts of wax finishes?

 

[MdB]

We have used Osmo Polyx on an oak window sill in the bathroom - uninsulated, cold and with mould all over the ceiling - not the best environment for wood. The finish is starting to suffer a bit after three years probably due to how often it gets damp so I'll maybe get around to cleaning it up and putting another couple of layers of polyx onto it when I can be bothered. All the other window sills are fine as are some oak cupboard doors also in the bathroom so you can count me as an Osmo fan.

 

[Penners]

FF - the following is based on no experience whatsoever, so MdB's empirical knowledge is far more important than mine. My comments aren't much more than supposition.

However, I imagine that the success or otherwise of a wax treatment in a high-humidity area will depend on the extent to which the wax effectively seals the wood. If you get a good 'seamless' coating of wax, then I can see this shrugging off condensation much more successfully than a finish that leaves microscopic routes by which the water can pene trate and get under the wax. So if you want to use a liquid wax like Liberon, I would tend to apply several coats to ensure this continuity of finish.

I haven't used Osmo Polyx but I have formed the impression that it contains hardeners and 'skinning' agents that make it superior to a simple wax.

 

[Flyfisher]

That makes perfect sense to me and was pretty much my own line of thinking. I hadn't really considered floor finishes on the assumption that their main difference would be to do with durability, which is something I wouldn't need on windows and a door. I'm sure a floor finish would be OK, but it it really necessary?

I've used Liberon liquid beeswax before and have been pleased with the result, though not in a kitchen area.

I'd normally just go with my instinct - after all, how much harm can beeswax actually do? - but having spent a small fortune on the windows and door I feel a modicum of research is warranted!

 

[DJH]

Linseed oil perhaps Flyfisher? Hope you are feeling better.
Doug

 

[Flyfisher]

Thanks Doug; still a little sore from all the prodding about but nothing to complain about really, given the alternative!

I had discounted linseed oil on the basis that it wouldn't be as easy to clean as a beeswax finish. If I was intending to treat the exterior sides of the oak then I'd likely use linseed oil, but for internal use I've always thought a wax finish would be better and also easier to 'top-up' as necessary.

But this is only based on what I've read and not from direct experience.

 

[masochists-r-us]

Having tried both raw and boiled linseed oil and Osmo Polyx, I would choose Osmo every time. Externally, have used the UV protection oil as I noticed that the ones I treated with linseed started to go very yellow and looked awful. The UV oil addresses this.New oak lintels we installed externally were not treated at all and have gone silver so if that's the look you want, I suggest you leave them bare. Internally, I wouldn't consider anything but Osmo unless you want to spend all your time re-finishing. Osmo gives a superior finish that lasts and lasts. Go for the Rapid version though as it dries a lot quicker.

 

[andrew gayton]

Although not oak, I have used R.L.O on beech worktops. 3 coats applied approx 10 years ago and the oil is still doing its job........... and yes, the kitchen is used. From my experience a beeswax finish can be short lived and not overly durable where as R.L.O will penetrate the wood and once dry and actually be polished (similar to French polishing)

 

[skier-hughes]

I've used Holkhams Linseed on our internal oak doors in kitchen and on all kitchen unit doors.
Looks lovely.
Very easy to put on
Cleans simply
easy to top up - bar our dogs love it, so they have to be banished while it dries!!
Very durable
In the last 3 or 4 years I've done a total refinish once, but that wasn't required, we were just finishing off some work, I had some oil to hand and started refinishing and carried on until I'd done it all, took me about 90 mins and we have 3 full doors, 8 unit doors, 3 drawers, 9 shelves and a welsh dresser - ok it took 3 days to remove everything and put it back ..... well not quite, but the refinishing work was nothing in comparison to the clearing of units!!!
The smell is divine

I quite like linseed, can you tell

 

[masochists-r-us]

Whilst Holkham's may be fine on doors, if your windows are single glazed like ours and run with condensation on cold days, you're risking water marks on your oak. I know through painful experience.

 

[Flyfisher]

The windows are double-glazed (they are for a completely new extension, not replacements), so I'm not expecting a big condensation problem.


Thanks for all the comments, confusing though they are. It's difficult to find a consensus on 'the right' sort of thing to do - at least not from all the reading I've been doing, including this interesting thread from the green building forum: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=596&page=3

I'm comfortable with my decision to leave the outside faces untreated and am happy to let the oak weather naturally. it doesn't seem to have done the exposed house timbers any great harm over the past 450 years so I reckon the new oak windows and door will see me out.

So the main dilemma is the internal treatment. Linseed oil seems to be popular but not without its own problems, though I'd hope that a high quality formulation would minimise them. My instinct is that a wax finish would be easier to clean and keep clean, hence my thoughts about beexwax. It may need periodic refreshing, but then so would an oil finish from what I've been reading - in which case I'd expect wax to be easier than very slow-drying oil.

I'm actually tempted to consider leaving the inside faces untreated as well as the outside, though I presume this would lead to localised and unsightly staining rather than an overall silver/grey weathering, quite apart from it not 'feeling right' though I'm not entirely sure why.

I bet the people who built the house 450 years ago didn't worry about these sorts of things!

 

[tobydog]

FF - our new kitchen extension is slightly smaller than yours at 24' x 12'. It's doubled glazed with untreated oak for the cills and boarding weathering nicely on the outside and water based eggshell inside. We have a vaulted ceiling (as I recall yours will be) and we have never experienced any condensation issues even during the hardest of the recent winters we have just had. With adequate ventilation and extraction I reckon you can do what you like because a kitchen will only get steamy if you let it and a room your size would need a lot of steam. If you think you're going to make a mess then please listen to the experts and not me.

 

[Flyfisher]

Thanks for that, Tobydog, very useful experience about the behaviour of a kitchen with such a large ceiling space. It confirms my expectation that steam and condensation shouldn't be a problem especially since we'll have extraction anyway (whilst cooking) and a large opening rooflight as well.

 

[skier-hughes]

So the main dilemma is the internal treatment. Linseed oil seems to be popular but not without its own problems, though I'd hope that a high quality formulation would minimise them. My instinct is that a wax finish would be easier to clean and keep clean, hence my thoughts about beexwax.

I don't think so, our oiled oak has dogs running past it all day, every day, it has me drilling, knocking off plaster etc in the utility and all it needs is a wipe over with a damp cloth.


It may need periodic refreshing, but then so would an oil finish from what I've been reading - in which case I'd expect wax to be easier than very slow-drying oil.

I heat up my oil before applying, it soaks in well and in a warm kitchen is dry in a day. Lot longer than instant with a wax, but as for reapplication, maybe once every ten years maybe would be good for oil......... unless you follow the proper routine of once a day for a week, once a week for a month, once a month for a year.......

I bet the people who built the house 450 years ago didn't worry about these sorts of things! I bet they did!!

 

[Flyfisher]

Some good points there, but I really think it's only the door that will be subject to such wear and tear. The main window will be above the kitchen worktop and the other two are high up in a cloakroom and stairwell respectively, so they should be fairly rarely messed about with, especially since only the cloakroom window has opening casements.

As for the 'proper routine', I seem to remember posting that some years ago (you missed out the 'once a year for life') , so I'm not a total stranger to linseed oil. :wink:

But oiling once every 10 years hardly sounds particularly onerous, so you're messing with my final decision again!

 

[Essex]

Our oak is silvering nicely externally and we have used beeswax on the internal surfaces (not doors) in the kitchen, works well. Kitchen 4 x 8m. Mind you I oil our oak worktops with Aldi olive oil, which also works well.

 

[Flyfisher]

That's encouraging to hear. How long have the windows been weathering?

 

[DJH]

Sorry about hijacking your post Flyfisher but it's a good opportunity to remind anyone who is fitting new oak windows and intends to flash them with lead sheet which is necessary especially within a timber frame such as a dormer, that to stop the lead corroding from tannin leaching off the oak when it gets wet, and also leaving unsightly brown stain stains, the lead should have at least two coats of a hard setting bituminous paint to prevent this problem happening.

Doug

 

[Essex]

External oak been weathering for 5 years

 

[plasticpigeon]

Maybe this is a dirty word on here but why not use an oil based polyurethane lacquer if you are worried about wear and wet?