Woods Open Air coop folks: help me with a Suskovitch tractor hybrid

[Sunshine_Amy]

Hello good folks,

Y'all helped me with an earlier chicken tractor design concept based on the Suskovitch Stress Free Chicken Tractor, a tarp covered structure similar to some of the hoop houses here on BYC. I'm halfway through the basic build, and now that I have my chicks, a couple of things have changed. The short answer is: chicken math! I'm up to 8 birds. So I'm revising the plan, and treating it less like a coop + run, and more like a spacious coop, which will have additional run space. With an eye towards winter, I have three concepts for ventilation, and I'd like to hear from those familiar with the Woods Open Air Coop, which option seems the most comfortable option for the birds in the cold New England weather.

Below is a mockup. Options A & C have fully closed backs, and open fronts, mimicking structures in the Woods book. Option B would need slatted louvers or some such (I'm open to suggestions!) to keep the birds dry. As far as condensation on interior tarp, which seems a concern for A & C, I've got hardware cloth on the inside of the framing to keep birds from touching the tarp, and the angle of the roof seems steep enough to carry any wetness towards the sides where they'll be out of contact. I'm willing to duck through a low doorway for Option A if it means happier birds in the coldest season, so again, based on your experience with these, let me know what basic design plan would make the most comfortable birds, and I'll go from there. THANKS!

 

[Ted Brown]

The info in the book on a Woods KD coop does not go into details of why it works although various other folks have pointed out that the dimensions shown (10' by 16', 8' by 12' or 6' by 10') result in the ability to circulate air in and out of the front of the coop during cold weather. In warmer weather the side and upper monitor windows are open and the air flow is totally different. Note that with the winter setup the air intrudes into the front lower section only because of the "air cushion" that is created in the back higher section.

In short your proposed structure is different, the use of tarps over HC will not be air tight and I very much doubt it will behave the same as a Woods.

 

[saysfaa]

The easy first. Posts set in cement rot faster than posts set in the ground without cement. A bit of gravel in the bottom is good, so they say in most respectable fence building resources. It doesn't make a significant difference in my sandy soil; I'm not sure what it does in other types of soil. Fyi, if you haven't thought of it - if you are setting the posts at all, it is best to set them below the frost line. And to dig the hole with a post hole digger to get as small of a diameter as possible, and to tamp them in as you fill the hole.

If you want to raise it to discourage rats and such, I'd go higher than 1'. One foot provides shelter as much or more than it makes it hard for the attackers to reach it and is too low for you to crawl under after chickens or eggs. If you are screening it to keep all the critters out then you may as well put it on the ground and have less to screen. If you want it 1' high for other reasons (to give clearance for snow, for example) than it is worth the extra materials and effort to screen it.

As for the three options. I would discard B first. Tolman (who has coops' Woods recommends in his books - for those who haven't read the books) had something like this his first year (taking big windows out of both sides of his existing coop) and says it was much healthier than his previous closed buildings - and that he shoveled snow out regularly. So the next year, he changed to having one end completely open and the other three sides completely closed, instead. https://archive.org/details/openairpoultryho00wood/page/82/mode/2up?ref=ol&view=theater pages 82 -86 of the 1912 edition.

The *superior to most coops but not as comfortable as another option* concept is comparing a coop with the ridge line running north/south vs east/west on a coop with the open side to the south.

The proportions matter. I know my 5' of open side worked last winter for a building with 10' of depth. I don't know how much of the success was having 7' to the top of the walls, though. The classic Woods' coop as it has been known on Backyard Chickens Forum has a 3' high open front for the smallest version (the 6' wide by 10' deep version) but it also has a 5' high rear wall and a peak higher than that. That gives the warm, moist air somewhere to rise to before it wafts down the front slope of the roof. I don't see height dimension on yours but if it is a beefed up chicken tractor it may have short walls? I don't know all the ways the proportions matter.

Condensation should not be an issue unless you have a metal roof. The suspended ceiling might help with the air circulation (as Tolman liked the side open rather than the end) - or it might cut down on the total volume of air inside the coop (if there are short walls and that is a problem).

 

[Sunshine_Amy]

The info in the book on a Woods KD coop does not go into details of why it works although various other folks have pointed out that the dimensions shown (10' by 16', 8' by 12' or 6' by 10') result in the ability to circulate air in and out of the front of the coop during cold weather. In warmer weather the side and upper monitor windows are open and the air flow is totally different. Note that with the winter setup the air intrudes into the front lower section only because of the "air cushion" that is created in the back higher section.

In short your proposed structure is different, the use of tarps over HC will not be air tight and I very much doubt it will behave the same as a Woods.

Excellent points, thank you. The air cushion concept helps me to realize how important a very light seal at the back would be to make the concept work. In that case, what are your thoughts on option B? How comfortable would the birds be in it, compared to a Woods?

 

[Ted Brown]

I do not have any experience with coops other than my 10' by 16' Woods.

When I looked at your diagrams I thought that option B would work well given air flow overhead vs the others. However, important to follow the 1 square foot of ventilation per bird rule.

Also worth noting:
- I have had a mix of breeds and am currently tying to shift to Chanteclers as they are very well suited to my climate. Large combs and waddles do not work well in cold climates.
- Even with the Woods one must be careful to monitor frost on the walls on the very cold days.
- I have a 400 sq foot covered, predator proof run attached to my Woods; pop door is open 24/7. Big decrease in bother for me as I do not have to open the pop door early in the morning; birds are happier.

 

[Sunshine_Amy]

The easy first. Posts set in cement rot faster than posts set in the ground without cement. A bit of gravel in the bottom is good, so they say in most respectable fence building resources. It doesn't make a significant difference in my sandy soil; I'm not sure what it does in other types of soil. Fyi, if you haven't thought of it - if you are setting the posts at all, it is best to set them below the frost line. And to dig the hole with a post hole digger to get as small of a diameter as possible, and to tamp them in as you fill the hole.

If you want to raise it to discourage rats and such, I'd go higher than 1'. One foot provides shelter as much or more than it makes it hard for the attackers to reach it and is too low for you to crawl under after chickens or eggs. If you are screening it to keep all the critters out then you may as well put it on the ground and have less to screen. If you want it 1' high for other reasons (to give clearance for snow, for example) than it is worth the extra materials and effort to screen it.

As for the three options. I would discard B first. Tolman (who has coops' Woods recommends in his books - for those who haven't read the books) had something like this his first year (taking big windows out of both sides of his existing coop) and says it was much healthier than his previous closed buildings - and that he shoveled snow out regularly. So the next year, he changed to having one end completely open and the other three sides completely closed, instead. https://archive.org/details/openairpoultryho00wood/page/82/mode/2up?ref=ol&view=theater pages 82 -86 of the 1912 edition.

The *superior to most coops but not as comfortable as another option* concept is comparing a coop with the ridge line running north/south vs east/west on a coop with the open side to the south.

The proportions matter. I know my 5' of open side worked last winter for a building with 10' of depth. I don't know how much of the success was having 7' to the top of the walls, though. The classic Woods' coop as it has been known on Backyard Chickens Forum has a 3' high open front for the smallest version (the 6' wide by 10' deep version) but it also has a 5' high rear wall and a peak higher than that. That gives the warm, moist air somewhere to rise to before it wafts down the front slope of the roof. I don't see height dimension on yours but if it is a beefed up chicken tractor it may have short walls? I don't know all the ways the proportions matter.

Condensation should not be an issue unless you have a metal roof. The suspended ceiling might help with the air circulation (as Tolman liked the side open rather than the end) - or it might cut down on the total volume of air inside the coop (if there are short walls and that is a problem).

Great points on the height of the platform. I have read the Woods book, but not the Tolman book; thanks, I will check it out.
I am familiar with the ridge line difference and that this one is more like the Tolman plan as it appears in the Woods book. Footprint is 6x10, heights are 1foot per square on the graph paper.

@Ted Brown made a great point about how the air flow functions, and I think despite best efforts to make good seal at the tarp edge, it’s not likely going to hold up against pressure. Which means I should abandon lower front ventilation, as that’s just going to be very drafty and uncomfortable.

I’m leaning towards option B. Of course, I don’t want to be shoveling snow or, worse, dealing with occasional rain and then freezing weather coming through the upper vents and compromising the birds’ health, so I would have to install wooden slats on those vents. A bit of a pain, but I don’t see any other option for keeping the birds dry and comfortable.

Thank you both for your help, this has been very helpful!

 

[Ted Brown]

@Sunshine_Amy I am not certain that there is a "Tolman Book" but the chapter on his coops in the Woods book is useful.

 

[saysfaa]

... wooden slats on those vents. ...

I don't know much about non-three-sided options for winter so maybe someone else can help further.

I do know slats won't keep snow out. Some people use furnace filter material to keep snow from coming through ventilation openings. Aart is one, I don't know how to tag people, but you could narrow a search by adding author info.

 

[Ted Brown]

@aart see post immediately above.

 

[aart]

Some people use furnace filter material to keep snow from coming through ventilation openings. Aart is one,

@aart see post immediately above.

https://www.backyardchickens.com/articles/ventilation-baffling.75434/