OSB walls?

[Northern Flights]

With any wood product, it's all about sealing it. If you want permanent, use stone, otherwise seal the fibres with an epoxy/composite of some type and enjoy. OSB is better than most because it already contains a waterproof polymer at manufacture. Plywood isn't as durable.

And to those that claim it will not absorb stain, try it before trashing it. I'm sorry for being so blunt, but I bristle at being accused of exagerating. At least when I'm not trying...

 

[Mamatomany123]

We used OSB board for our addition. We sealed and painted it with a few layers. It hasnt been long but si far its holding up. We also ,(obviously) have it elevated so it never sits in water and the roof overhangs helps it not get wet when it's a calm rain. We did anchor it down into the concrete and it is also attached to that metal post which is in the concrete. The door is not osb but we stained then sealed that as well.

 

[Folly's place]

Back to the rat poison issues here; when you do have a rat infestation, they do kill chicks and bantams, and if that's who you have, it matters a lot! And, besides fixing entry points and nesting areas in the coop, poison is often the only real solution, because the rats are so very smart. Most dying rodents do go back into their burrows to die, and careful use of bait stations in the coop only makes it as safe as possible.
I've been there myself, and there's a difference between what's best and nicest, and what sometimes needs to be done.
Mary

 

[K0k0shka]

Wow, that's one determined rat! Rats can chew through regular wood too, though. Might be easier with particle boards like OSB, but I guess no wood is really safe. When I was growing up we had mice chew through tin barrels to get to the feed grains on the farm. Is there anything truly rodent-proof?

Also, you say it won't keep predators out, but the example is of a rat. A rat is not a predator, it's just a pest. I won't keep chicks in there, just adult hens or at most, pullets... Would a rat be truly a predator and eat my pullets? The true carnivorous predators that eat chickens don't have wood-gnawing teeth... Would they be able to chew their way in?

 

[K0k0shka]

My coops are OSB walls. Painted every other year on the outside, no paint on the inside. I use Rustolium brand heavy duty oil based enamel paint. It penetrates and coats good. Plywood will last longer but OSB is much cheaper.

Glad to hear, thanks. Do you repaint because it's wearing off and it starts to show, or just in case?

Rats will absolutely kill and eat chickens.

Full grown chickens??

 

[K0k0shka]

@Gray Farms How do you keep the rats out then, if your coops have OSB walls?

 

[RavalliSurfer]

Until OSB gets wet, it's pretty good as a barrier but I also used some scrap construction materials to build my coop.

First..... it's elevated 4' off the ground on 2x6 legs, triangulated and California cornered. The walls are triple thick with plastic shopping bags inside for insulation and a leftover piece of 3/4" marine plywood as the bottom of the coop..... again with a dead air space of 2" again, labrynthine-filled with those shopping bags.

All the interior is faced with 10mm OSB, waxy side inward. I've sealed and painted all the exterior walls with a semi-gloss alkyd enamel for water repellency and the roof is a mono-laminated and cantilevered single piece of exterior grade OSB, covered in a plastic roofing underlay material.... awaiting shingles at this date.

The outside is covered with textured cerracrete skirting and surplus soffet material with built-in louveres from multiple construction sites..

There is no place that a predator can stand upon to reach the coop from the ground and the underside floor being the first line of defense is a lot of trouble for even a 4 foot tall animal to reach in the first place.

Like I said, a bear or a sasquatch might get in..... but by then all bets are off.

Oh yeah..... (edit) the coop is on doubled 2x8 runners so I can move it and the run every once in a while to give the birds fresh grass to munch. In the winter I don't think it's likely to move the coop on top of the snow.... although a coop on sleigh runners might move pretty fast.

 

[Folly's place]

Our three sided run-in sheds are also on skids, and twice one or another of them have BLOWN OVER in strong winds. Once, it landed on it's top! This won't be good for chickens. You can get anchors to drive into the ground, and I'd consider it.
Neither episode involved actual tornadoes, either.
Mary

 

[K0k0shka]

Most important is what you use to seal it with. My parents used a Solid Color stain on their deck, it is only a year old and pealing already. I used a Transparent stain that will not have the solids in it to water proof my chicken tractor. I will have to see how well it holds up. It did soak in a lot of the wood sealant on the first coat and not so much on the second, so I believe it is well sealed.

Yeah, I'm trying to figure out the best product to seal it with. I got some solid color stain as well, but it says it's specifically made for waterproofing, and it's a stain and seal combo. I hope that holds up. Decks are tricky though, they get a lot of wear and abuse so I don't want to compare a deck to a coop wall in terms of stain longevity... There are special products for decks, that hold up better to foot traffic.

 

[RavalliSurfer]

Our three sided run-in sheds are also on skids, and twice one or another of them have BLOWN OVER in strong winds. Once, it landed on it's top! This won't be good for chickens. You can get anchors to drive into the ground, and I'd consider it.
Neither episode involved actual tornadoes, either.
Mary

Perhaps a little clarification by me is in order.

The coop is actually square and is above grade level by 4 feet. It has 4 legs that are California tri-cornered with 2x6 at a 90 degree angle to a 2x8 running lengthwise.

10 inch lag bolts and 3/8 inch carriage bolts affix each leg to the subframe of the coop - which is a sheet of marine ply and a labyrinth of supports to keep a 2 inch space for insulation in the floor.

Where the legs meet the ground, I have a pair of runners on two sides - these are laminated from 2 2x8s, with a turned-up nose for forward motion. I pull the coop with my Suzuki Quad-Runner in LOW Range. It works.

Any wood in contact with the ground is treated with a 24-hour dip into some creosote that I have that the State of California never knew about nor seized from me as a Class I Carcinogen. To dip long boards, I just used ABS pieces of gutters with end caps. That way I can keep the ends IN the chemical and make sure it is absorbed.

I love the smell of creosote - brings back memories!

I digress.

The caged 'playpen' for the chickens is on it's own runners that are doubled-up 2x3 hardwood from a pallet, and there is a towing chain on it if I have to move it separated from the coop - like when I have to make a sharp turn in the back yard.... otherwise, the playpen follows the coop as I tow them both to new grassy areas.

I estimate that the coop weight is somewhat over 300 lbs by itself with all the triple-walls and support beams in it - plus OSB isn't very light either! I used over 9 lbs of screws, a few lbs of 'other' hardware and bolts, lags n' such.

Even the cantilevered roof is over 40 lbs. I built this coop extra-heavy - for which I have been derided by a good friend. But he raises his chickens in converted refrigerators - so he can't really talk about this weight to me!

So-o-o ---> blowing over in the wind isn't in it's future at all as I see it - and we don't get killer 60 MPH winds on this side of The Continental Divide anyway. Winds of any ferocity are an Eastern Montana product.