Treating exterior fences

[Mrs.R]

I have wooden fences in my garden the rough sawn boarded type that are vertical slats that lap over one another.
Not my choice but we have to go with whats there, a wall would be lovely but when the garden is very long its out of the question, would cost so much!
Anyway cut to the chase, i have cleaned these up as they were quite green and would now like to treat or oil them with something, i dont really like the large tins of chemicals as the smell lingers and am not a great fan of them.
Has anyone tried linseed oil on exterior woodwork, drying time is not a great issue as no one brushes past them.
Or could anyone suggest some other type of natural oil.
I see Fiddes are doing boiled linseed but no chemical additives (hot air blown through it, so the website states), has anyone tried this.
Hope someone can point me in the right direction, as this is job i would like to do soon so can hopefully settle back and enjoy what summer we may have.
thankyou all.

 

[Penners]

Although |I've never used linseed oil on fence panels, I can't see any reason why it shouldn't be effective. It's certainly a widely used treatment on exterior wood items like windows and doors.

The only thing I suspect you may find is that, on rough sawn fence panels, you'll use a lot of the stuff. And being rather poor quality softwood, they'll expand and contract a lot with changes in weather, thus requiring more frequent re-oiling.

 

[biffvernon]

You need to know why you want to treat the wood.

Yes, boiled linseed oil is linseed oil that has had hot air blown through it, as it says one the can but linseed oil, boiled or raw, has absolutely no fungicidal properties so won't slow the rate of rot.

You may be fortunate and have a fence made of western red cedar or another semi-durable softwood, or it may have been pressure treated with poisonous chemicals a long time ago. I'd say that your best bet to maximise its lifetime is to keep earth clear of the bottom so that it gets a chance to dry out in the sunshine. Moulds hate that.

 

[Feltwell]

linseed oil, boiled or raw, has absolutely no fungicidal properties so won't slow the rate of rot.

How does it work on stopping joinery items rotting then Biff? I don't doubt you're right, just keen to know how it stops my painstakingly restored sashes from deteriorating!

I would have thought that linseed oil would be a very expensive way to treat a fence as well, and I'm sure I remember someone (probably Biff) saying that cheap impure oil tends to make exterior wood go black after a while.

One thing not to bother with is the DIY shed's items with names like "Shed & Fence Care", including branded ones. They are literally 98% water, the rest is a dye and (on the slightly more expensive ones) some wax. They do nothing except colour the fence - the pricier ones with wax in make the rain bead up on the fence, bit like after you've polished a car. I used to work with the 3 main UK manufacturers of these products.

 

[biffvernon]

How does it work on stopping joinery items rotting then Biff?

It doesn't!

Well, I suppose that an oily layer might shed the rain quicker, keeping the wood drier, so it might do something, but linseed oil is certainly not a fungicide. The point about some cheap oils is that they have a protein content that actually supplies nutrient for slime moulds.

 

[Lime]

i would not wish to be in the vicinity of the fence on a hot summer's day.
It will smell like a linseed oil factory for several years.

 

[Feltwell]

I think linseed smells quite nice!

We had a customer complaint that reached me one time when I worked at the head office of one of the big DIY chains. A customer complaind that they had painted their lounge floor and 3 weeks later the room still smelt bad. When asked what varnish they had used, they said that they hadn't used varnish - they wanted to stop the floorboards from rotting, so they'd used creosote.......

 

[Flyfisher]

Well, it probably did the job! :lol:

 

[FamilyWiggs]

...we have to go with whats there, a wall would be lovely but when the garden is very long its out of the question, would cost so much!

If you're going to use linseed oil on a long and rough sawn wooden fence, can you let me know first please? I'd like to buy Holkham shares before you start - their value will rocket based on the turnover you'll generate! :shock:

 

[Gareth Hughes]

There used to be this stuff called creosote, but unfortunately someone with too much time on their hands found that if you make lab rats drink it for weeks, it kills them, so painting your fence with it is now a no-no.

 

[Gervase]

You can get a creosote substitute which doesn't smell as nice but is supposed to be effective. Linseed oil could attract a lot of algal growth, leaving you with a bright green fence. Which may or may not be a good thing.
Alternatively - and probably still cheaper than using linseed oil - you could get a fencing contractor to put creosote on your fence. Its sale has only been banned for mere 'amateurs' who might want to use it once in a blue moon. Bizarrely, professionals, who might use the stuff on a daily basis (and therefore run a high risk of skin cancer) can still buy 20-litre drums of creosote. The usual HSE blather is here.
It just goes to show, you can't be too careful. :wink:

 

[worms]

Ok, time to get shot down in flames again, as I have in the past on this subject...

I'm afraid I still use waste engine oil mixed with petrol. I know all the reasons why I shouldn't, but in the absence of good-old-fashioned creosote, it really is the next best thing.

The last time this came up I was advised to use diesel as a diluent instead of petrol, but there is always a jerry can of petrol to hand when you need it and never a can of diesel, so I am afraid I have yet to follow what is probably very good advice.

 

[Feltwell]

Ok, time to get shot down in flames again

Shot down in flames? Engine oil & Petrol?? Sounds more likely that you'll go up in flames!!!!! :lol:

 

[Feltwell]

You can get a creosote substitute which doesn't smell as nice but is supposed to be effective.

You can it cheaper than that from B&Q I think - they stock Bartoline Creosote substitute. Very high in VOCs though, as I presume is the one on Wood Finishes Direct, it looks like much the same stuff. It's basically a cheap solvent based preservative with dye in.

I agree it was daft that they banned the DIY man who uses it once a year, but the fencing contractor (who quite probably gives that menial job to the 16 year old "YTS" lad to do) can still use it. Traditonal creosote was made from coal tar I believe? That's not been available for a long time - the stuff called creosote they banned about 5 years ago was a substitute in itself, I was dealing with Bartoline when they had to stop selling it.

What is it with the smell of creosote? It seems to have the "marmite" effect - you either love it or hate it. It always makes me feel nauesous.

 

[worms]

From DIY wiki
http://wiki.diyfaq.org.uk/index.php?title=Wood_Preservatives

Oil based Preservatives
Used engine oil mixed 50/50 with paraffin or diesel has long been used as a wood preservative. It is very effective, but there are now concerns about the possible toxicity of contaminants in used engine oil.

New engine oil does not contain engine contaminants, and a new oil & paraffin mix will be discussed here.

Fully effective
Long lasting - many years
Low cost - typically around £3-4/gallon retail
Safe to handle
Preserves wood in constant contact with wet earth
Drawbacks
There are 3 drawbacks, all of which are temporary, and disappear in the days following application.

Temporary Oiliness When initially applied it creates an oily surface. Within a day this soaks into the wood, leaving a dry surface.

Flammability concerns Like any spirit based product, an oil & paraffin mix is flammable. However it can not be readily ignited like petrol. Neither diesel nor engine oil will ignite when a naked flame is applied, and nor does a paraffin & oil mix. Paraffin is more flammable than diesel, but quickly soaks in then gradually evaporates away. Wood so treated does not become an increased fire risk, the prime problem is public perception.

Whiff Paraffin creates a very mild whiff as it evaporates. This is temporary & harmless, though it lasts for many days. This makes it ill suited to indoor use.

Don'ts
The paraffin can be substituted with diesel, kerosene or heating oil, but not with white spirit or petrol. White spirit is not effective, and petrol is dangerously flammable & toxic.

Don't use engine oil alone. Some oils soak in well, but engine oil sometimes does and sometimes doesn't.

Being too mean to add much of anything that has cost money to the mix, I have tended to use about 5 parts oil to about one of petrol (which the above confirms is an unwise thing to do) and I would imagine that the same proportions of oil to diesel would work just as well.

What the DIY wiki piece doesn't answer is the issue of the heavy metals contamination in the waste oil and the volatile components that end up in the atmosphere... I guess an innocuous preservative is actually a contradiction in terms and the best answer is to let the wood slowly decay naturally. It just goes so much against the human instinct which is to do everything to protect our hard work in putting up the fence in the first place.

 

[biffvernon]

Alternatively:

A) Use a timber that is more durable.

B) Make friends with your neighbour so you don't need a fence.

 

[Penners]

get a fencing contractor to put creosote on your fence. Its sale has only been banned for mere 'amateurs' who might want to use it once in a blue moon

Psssst! Wanna buy a 5 litre plastic tub of brown liquid that I've had stashed in the shed for years?

Nudge, nudge - know wha' I mean?

It'll costcher though...