Treating exterior wood

[BabyBantam]

Well, the rain is definately back!
My ark is made of preasure treated wood, but due to last summer being so dry, never got round to varnish/treating the outside. Now it's so wet, I've got (apart from the leaks), green algi growing all over the outside as it's just NOT got the chance to dry out. The ends, although drier, are now spotted with black mould whish isn't good either.
Can anyone recommend an exterior treatment (presume it must be water based) that won't give me a 'shiny' outside, for when it finally stops raining?

 

[chrismahon]

You have two problems there BB. Waterproofing and preservative. First thing is to scrub off all the mould and kill it completely. Soap and water, dry it thoroughly, then Cuprinol 5 star will get into the wood and kill the fungal spores. Then Cuprinol Clear Wood Preserver all over will stop it coming back (so will 5 star but it's twice the price). I would then, after thorough drying for two weeks, use Cuprinol Garden Shades to apply a waterproof but breathable surface. You could just give it a good soaking in Cuprinol shed treatment, but it rapidly loses any waterproof capability, but as a preservative it is excellent. Did two sheds 10 years ago and no rot, although one in the shade is going a bit green now. The preservative isn't water based so it soaks in. The shades is and dries quickly.

The problem you will have is all this drying time. You need several weeks of scorching weather or a dry carport and a spare coop. A hasty alternative is to scrub the mould off and paint the Shades on while the wood is still damp. Problem is it will flake off within a year. Or scrub the wood, let it dry for a few days and use garden shed preserver. You could keep topping that up and perhaps the fumes will kill red mite, but not sure about your chickens going in for a few days.

 

[BabyBantam]

Oh dear - another morning of rain, chooks wearing mud boots and no drying time. At work this morning, but feel another trip to find a gazebo coming on....

 

[BabyBantam]

Chris,
How long do I have to remove the chooks for when using the Cuprinol 5 star. Can I put them in after 24hours, or do they need to be re-housed for weeks? I managed to get a gazebo yesterday (of course the sun was out all day) and can afford the 5 star too, but don't want to treat till I know I'm not going to poison the girls.
Ta.

 

[Marigold]

Don't know about the Cuprinol, but I used the Wickes stuff guaranteed for 5 years on my quail shed, an oil-based treatment so not the water-based sort like the ones which only claim to be effective for 2-3 years. It did the job but took forever to dry off unless I could put the treated parts out in sunshine, when it went off very quickly, in a couple of hours. I was painting in the garage with the door open and under cover, but without the direct sunshine it just wouldn't dry properly. (This was back last October when there was some sunshine!) I expect water-based treatments dry faster but don't last as long.
Once the wood feels properly dry, ie nothing comes off on your fingers when you rub it, I would just have a good sniff and if you can't smell anything then it's probably OK.

 

[chrismahon]

Hi BB. Cuprinol 5 star soaks in very quickly and kills the spores which will now be in the wood (from the mould growth). I don't know of any other product that does the same as they are all meant to go on good timber. I have tried Cuprinol shed preservative on some mouldy bits on our shelters and they just grew back! 5 Star is a very thin liquid so soaks in fast and penetrates really well. It does have an odour though. If you are not using it inside the coop I would leave it 24 hours or until the smell has gone. Tin says you can't paint over it for 6 -8 weeks as it takes that long to dry completely -we painted Cuprinol garden shades over some at 4 weeks and it stuck fairly well, although some flaked where it still hadn't dried. We are just about to do the same on our shelters and will paint then with Shed Preserver 24 hours later.