What stain, preserver, paint should I use on my tanalised timber obsy?

[Chris]

Hi guys,

I've reached this stage of my build and I'm going around and around in circles as to what I should use and when? The shed I converted is a pressure treated tanalised one according to the company I bought it from. Research has showed that you shouldn't paint freshly tanalised timber but I can't find any info on how long to wait before its safe to do so? The shed was delivered in May so the timbers been weathering for around 6 months, does anyone know if this is long enough to allow paint/preserver to stick properly?

Also I'm not sure what product to use, I'm really not keen on dark stains as I don't like how they look and a dark colour on the outside of the obsy will absorb a lot of heat making the obsy hotter on the inside in the summer time. I've been looking at the Cuprinol garden colours range of water based shed paints which have good reviews but I'm not sure how good a water based product would be for protection against weather and rot, or does this even matter if its pressure treated? I heard Oil based products are good for protecting timber but they tend to be really dark so I'm not keen e.g. Creocote. Can anyone recommend I good product that protects well and isn't a very dark colour? does any one have any suggestions as to what to avoid?

I did wan't to get some painting/preserving done tomorrow (weather permitting) as both me and my wife have the day off, but I still can't decide the best course of action:(

Help!

Chris

[pete_l]

I would expect the advice about not painting pressure-treated timber straight away is to allow it to dry out from the treatment, as painting wet timber would just make the paint blister. I'd expect that the bulk of the wood would have dried out sufficiently by now (though traditionally, weathering is rated at 1 year per inch of thickness).

So far as what to apply: I'd go with a spirit based wood dye. Axminster have a nice range: http://www.axminster.co.uk/wood-dye-dept206897_pg1/

[fwm891]

Hi Chris, Tanalising comes in different 'strengths' (wrong word but...) its a process whereby the timber is placed under a vacuum to draw the air etc out of the timber and then the preserver is added and the pressure taken back to normal - this forces the preserver into the timber fibres to replace the air etc drawn out.

It will depend what level of vacuum the product was under as to how far into your shed the preserver went.

If you have cut across any of the timbers - look at the cross section, you will see how far the preserver has been drawn in.

If there is any 'timber' colouration then you will need to apply a preserver of some sort to the end grain (timber absorbs liquids better in to end grain 10x approx).

Look at your treated timber if you see any crystallisation its likely to be water based. Most manufacturers use water based treatments these days as spirit/oil based products are more difficult to dispose of.

[Gina]

I used Ronseal Total Wood Preserver (£25 for 25 litres from Amazon) for my wooden observatory in addition to the original treatment. Cut ends I stood in a bowl of preserver for 10mins to soak it up. Then everything got the preserver well brushed in. Not cheap, but it's spirit based and considered by many to be the best. I don't want any rot! Vastly better than the water based stuff you get from the DIY stores.

[Chris]

I would expect the advice about not painting pressure-treated timber straight away is to allow it to dry out from the treatment, as painting wet timber would just make the paint blister. I'd expect that the bulk of the wood would have dried out sufficiently by now (though traditionally, weathering is rated at 1 year per inch of thickness).

So far as what to apply: I'd go with a spirit based wood dye. Axminster have a nice range: http://www.axminster...dept206897_pg1/

Thanks Pete, yes I think you're right about it having time to dry:) So if its 1" per year for weathering then I'm right on the money with 6 months and 12mm t&g. Thanks for the link:)

[Chris]

Hi Chris, Tanalising comes in different 'strengths' (wrong word but...) its a process whereby the timber is placed under a vacuum to draw the air etc out of the timber and then the preserver is added and the pressure taken back to normal - this forces the preserver into the timber fibres to replace the air etc drawn out.

It will depend what level of vacuum the product was under as to how far into your shed the preserver went.

If you have cut across any of the timbers - look at the cross section, you will see how far the preserver has been drawn in.

If there is any 'timber' colouration then you will need to apply a preserver of some sort to the end grain (timber absorbs liquids better in to end grain 10x approx).

Look at your treated timber if you see any crystallisation its likely to be water based. Most manufacturers use water based treatments these days as spirit/oil based products are more difficult to dispose of.

Thanks Francis, I reckon thats the best explanation off the tanalising process I've come across:) I've sawn through an off cut and basically where there are greenish streaks on the surface of the wood these extend about 2-3mm into the wood on the cross-section, although 2/3 of the streaks on the surface of the wood are various shades of yellow so I cannot see any boundary for these bits when looking at the cross-section, I'm starting to think that my tanalising is one of the weaker ones and this is a shame as I've based this mornings decision on the tanalising being at least as good as adding a coat of preserver. I basically needed to start painting today with the weather getting colder and wetter and not having that many opportunities to work on the obsy, I therefore plumped for the water based Cuprinol - Garden Colours range paint from the local DIY shop and have painted just to sides of the obsy with one coat so far, so rubbish progress really.

I think I need to do some damage control now and sand down the couple of ends of the timber I have painted then apply some wood presever there, and also to the sides I haven't painted yet. I will give the obsy 2 coats of the paint this year and one next summer when the wood shrinks a bit so I can get a good seal with the paint all round, none of this timber will be in contact with the ground so hopefully this will help and I guess I can check the timber regularly and nip any problems in the bud.

I wish I'd put this thread up a couple of days earlier so I had more time to let the advice come in, not the first mistake I've made with this build and it wont be the last:D

[Chris]

I used Ronseal Total Wood Preserver (£25 for 25 litres from Amazon) for my wooden observatory in addition to the original treatment. Cut ends I stood in a bowl of preserver for 10mins to soak it up. Then everything got the preserver well brushed in. Not cheap, but it's spirit based and considered by many to be the best. I don't want any rot! Vastly better than the water based stuff you get from the DIY stores.

I'm affraid I've panicked and bought the rubbish water based stuff:( although on the plus side the colour (sea-grass) looks fantastic! I'm going to get some wood presever to top up the tanalising and at least do the timber ends and around the bottom of the obsy plus the two sides that I've not touched yet so hopefully it will be ok if I paint it yearly after that:) Your Ronseal sounds much better though!

I blame Vic Reeves, he made me do it:D

[Chris]

I decided to do things properly and bought some solvent based pre treatment wood preserver. I rubbed down the thin layer of paint on the two sides I had done so the the wood was showing though, then I coated the whole shed top to bottom with the preserver paying particular attention to the timber ends, I continued basically until I ran out! I need to go and buy some more tomorrow so I can do a second coat. THEN! I will apply the paint:D better safe than sorry:)

Thanks to everyone for your advice:)

[laser_jock99]

Avoid water based 'treatments' at all costs. I've learned the hard way and wouldn't touch them with somebody elses barge pole now. Creosote or proper spirit bases stains/preservers is what you must use if you want to avois rotten wood in a year or two.

[Chris]

Avoid water based 'treatments' at all costs. I've learned the hard way and wouldn't touch them with somebody elses barge pole now. Creosote or proper spirit bases stains/preservers is what you must use if you want to avois rotten wood in a year or two.

Did your cladding really rot after two years!? thats herendous, why do the DIY shops mainly stock water based stuff if its this bad? I'm forever worried about this now, right so how long is the estimated life span of my obsy based on the following (I had hoped my obsy would last a good 6-7 years):

The foundations of my Obsy consist of raised seperated mortered slabs, on this I have a row of 6"x2" tanalised timbers with 3 coats of Cuprinol Ducks Back (which is water and wax based) with DPC where they meet the slabs. The shed I've converted is tanalised and the company (Timberland sheds) boast a 15 year timber lifespan?? on top of this I've coated the bottom of the obsy with a couple of coats of Cuprinol ducks back, then because I'm paranoid about them accidentally forgetting to tanalise my shed timbers I've spent the day rubbing the paint down so the wood shows though the paint so I can apply a solvent based anti rot wood preserver, then I will add another coat of this before I add 2-3 coats of water based shed paint. I'm kind of committed to using the paint know as I couldn't rub through all the paint just enough that the wood showed though to hopefully take up the presever, I don't think any solvent based stain will cover the sea-green paint up?

am I doing enough? my neighbour bought a cheap overlap shed and put one coat of stain on it and it seems ok two years on, could it be that you obsy see's its fair share of harsh weather in your location Laser_jock?

[Capricorn]

Just been doing windows and doors on the house.

Used the Sadolin Advanced One Coat - B&Q had an ofer of 3 for 2 and it was least expensive to get 3 one litre tins rather than a 2.5 litre tin. I have the Satin finish and in Mahogany.

Slightly reddish but the Teak I thought was too brown and wanted a bit less brown.

Pretty impressed, except that it isn't really one coat.

If you put one coat on to get the colour without the underneath showing through, then it can run - I tried it, 2 thinner coats 24 hours apart work best.

Finish is good and water runs off, completely sealed.

If the offer is still on then consider it, the 3 one litre tins mean you don't have to open a can until needed.

[Baffa]

We have LOTS of wooden houses in Sweden painted with Falu Rödfärg, I don't know if it's availible in UK but it lasts forever. You paint it on untreated wood and it just works. It's not uncommon to see old barns etc that haven't been painted for over 20 years and the wood is still in great condition even though the color of the paint is starting to show it's age. http://www.falurodfarg.com/eng/

[Chris]

Thanks Capricorn Sadolin is good stuff and I did see it in B&Q but I'm kind of committed to the paint as discussed above unless Sadolin will cover over sea grass green??

[Chris]

We have LOTS of wooden houses in Sweden painted with Falu Rödfärg, I don't know if it's availible in UK but it lasts forever. You paint it on untreated wood and it just works. It's not uncommon to see old barns etc that haven't been painted for over 20 years and the wood is still in great condition even though the color of the paint is starting to show it's age. http://www.falurodfarg.com/eng/

Thanks Baffa:) that was an interesting read, we could definately do with some of that stuff over here:), not seen anything like it though, I might have to start mining some Iron Ochre:D

[malc-c]

Avoid water based 'treatments' at all costs. I've learned the hard way and wouldn't touch them with somebody elses barge pole now. Creosote or proper spirit bases stains/preservers is what you must use if you want to avois rotten wood in a year or two.

Trust me - stay away from Crecote - it doesn't "seal" the wood and after a very short period of time (less than a year) will need re-coating

I applied three coats of the stuff last year - here was the result

I noticed that by spring of this year the wood looked really light in colour and that the shiplap always looked wet as if absorbing the rain rather than repelling it. So I opted to use Ronsil shed and fence preserve. Yes it's water based, but then cures to form a decent level of protection. The wood can still breath but water forms droplets and runs off. You can see just how much the wood had lightened in the image below

So far the observatory is looking every bit as good as it did the day I applied the ronsil stuff...

[laser_jock99]

Did your cladding really rot after two years!? thats herendous, why do the DIY shops mainly stock water based stuff if its this bad? Could it be that you obsy see's its fair share of harsh weather in your location Laser_jock?

Probably a bit longer than two years. The water based stuff I'm adavocating people avoid is the acrylic based rubbish which goes on more like gloss paint than something you might expect to soak well into the wood and preserve it like creosote does. The surface looked sound but water was building up behind the acrylic layer and the shed rotted from the inside out.

We used the Red Cedar version of this:

http://www.blackfriar.co.uk/wood-preservative

The weather up doesn't help- mainly horizontal rain. That's why my observatory is not made of wood- the main structural skin is sheet metal. It might look a bit agricultural, but there's a reason why cowsheds are made from this stuff and not shiplap- it won't rot and requires no maintenance. The wood cladding on the outside of my obsy is purely 'decorational' to make it look less like a cowshed!

Waney Edge pine 'over cladding'

We have LOTS of wooden houses in Sweden painted with Falu Rödfärg, I don't know if it's availible in UK but it lasts forever. You paint it on untreated wood and it just works. It's not uncommon to see old barns etc that haven't been painted for over 20 years and the wood is still in great condition even though the color of the paint is starting to show it's age. http://www.falurodfarg.com/eng/

That looks like interesting stuff- not available here. Looking at the Health & Safety data sheet in seems to be solvent free?

[Andyfx]

According to the website for that Swedish paint stuff, the contacts for ordering in the UK are as follows:

Eurban Ltd

Unit 1

33 Waterson Street

E2 8HT, London

U.K

e-mail: info@eurban.co.uk

www.eurban.co.uk

[OldSpanner]

DO NOT USE WATER BASED, IT IS RUBBISH.

Try this, get a 1/2 gallon of clear spirit based wood preserver from a builders merchant, Cuprinol or Blackfriers or similar. Now the interesting bit buy an external oil based gloss in any colour you like, you can even get these mixed to suit.

Add them together at a ration of approx. 1/3 preservative to 2/3 paint, you can adjust a little, the thinner it gets the better it will penetrate. A couple of coats with a good drying time between and you will get the colour you want in a soft sheen/ semi matt finish with a shed thoroughly preservative treated.