Northern coop plans - comments wanted, especially on ventilation

[MadChickensVT]

I'm building a coop here in Vermont to house our 15 hens and 1 rooster. All are supposedly cold-hardy breeds. See my sig line for the list. We get fairly cold weather here, and usually have a week or two of -20 at night and 0 during the day. It's somewhat windy at our location.

I ordered the lumber for the 8'x12' floor today and it'll be delivered tomorrow. It will be approximately 2ft above the mild slope. It's going to be 3/4" Advantech T&G, pressure treated joists, and 3 1/2" fiberglass insulation. I ordered 3'x100' of 1/2" hardware cloth which will be used to keep critters out of the floor and elsewhere as needed. I also bought a gallon of miss-mix linen white exterior paint for the interior and a gallon of primer. I'll probably put down some vinyl flooring at some point. I'm planning to use the deep litter method.

I decided to insulate the floor when I build it since it'll be hard to do later. That's probably the only insulation for now. If I notice a lot of condensation forming on the underside of the roof I'll insulate it to prevent the condensation from dripping on the roosting birds.

I still have a few days to make the decision on the details for the walls and roof, so I'd like to get some input on my plans, particularly the ventilation.

The coop will not be painted these colors! It will be stained in some areas and painted a similar color in others. The roof will be dark-green ridged steel.
The colors indicate the venting and the roof:
RED is summer-only ventilation
BLUE is year-round ventilation
GREEN is the ridged steel roofing

Here's the front of the coop. I'm planning a 3'x6 1/2' door in the front with the upper and lower areas screened with hardware cloth, with the lower area covered in plastic during the winter. It will face southeast into our side yard. There will be nesting boxes on either side with windows above them that will be screened with hardware cloth and opened for ventilation in the summer. The nesting boxes will be approximately 2ft off the floor so that they are comfortable to open from the outside.

Here's the back of the coop. It will face northwest which used to be where the prevailing winds came from, but these days who knows. The coop will be set back into the coniferous woods a bit so that it will be fairly sheltered from this direction, although it's on a hill so the wind does get through. I'm planning on having a way to adjust the amount of the hardware-cloth covered vent that is open year-round. The coop could be expanded in this direction to accommodate chicken math.

Here's the sides of the coop. Note that the side overhang and the nesting boxes are not shown. The vents will be tucked up under the overhang and boarded over in the winter.

There will be a pop door somewhere that I haven't decided yet, likely off the back into a pen. The chickens are allowed to free-range most days.

I'm not sure if I should vent the ridge or not. I could vent it just slightly by not using the foam sealing strips for the ridges, or I could even space the ridge cap up a bit and open up the gap between the panels. It seems like ridge venting would be good, but it would be hard to close it up.

Total winter ventilation as shown is 9 square ft: 2'x2 1/2' on the front and 2'x2' on the back. Plus I could vent the ridge. Or not.

I'm planning on having the roosts running down either side of the coop about 3 or 4ft off the floor just above 2 or 3ft wide shelves. Hopefully this will keep them far enough away from the cold air coming in the end vents in the winter, but I'm not 100% sure. I've read the thread on the Woods open air coops and found them interesting, but I want to access the coop from the front and they're setup for side access. Also they don't seem to scale down very well to the size I need. I've read a bunch about ventilation and understand that I need a lot. I'm trying to figure out if what I've shown is the right amount and locations.

Any comments? Thanks for any help

 

[oldchickenlady]

Everything I have read on this site says good ventilation is a must, even in extreme cold weather. There is a good article on here concerning that subject...type in ventilation in the search box and you should be able to find it. Too much moisture in the air (from their exhaled breath) can cause frostbite in extreme cold weather. Just don't have any vents positioned where air will be blowing directly on the birds. Mine roosted outside a lot last winter on a second level I put in their run, instead of their 8x8 coop, even when we had single digit temps. I had their run wrapped in plastic to prevent drafts, but the front was open. They did just fine.

 

[latebloomer]

hi

i'm in montpelier and this is going to be my first winter with chickens

this is my coop in progress

i have eight orpingtons and the coop itself is 84 square feet, it's a simple shed because i was building it myself

i used t&g advantec for the sheathing on the exterior of the framing and for most of the interior framing as well.

in addition, i have a hoop style run which increases the amount of space for the chickens, let's see if they continue to use it in the winter months....

i have advantec over my rafters, then roll asphalt roofing, and over that i have galvanized metal roofing (no more blue tarp),

i'm thinking about insulating the roof, but that's the only place i'd insulate

at this time, i'm considering using rigid insulation, friction fit, then spray-applied foam at the joints and seams

in my day job, i'm an architect, and i can tell you that fiberglass insulation does not work if it's at all wet, it does do a nice job of allowing molds and mildews to grow, so if you can, i'd recommend avoiding it

you can see i have plenty of ventilation

on this forum i've seen ten square feet as the recommended space per chicken, and a minimum of one square foot of ventilation per chicken

you'll have many comments, i'm sure on this thread, but i'm glad that you posted in the Vermont thread as well, i've taken to posting their primarily because the personalities are a bit milder, like in Vermont.

 

[sheila3935]

If you are already having condensation there is not enough ventilation. The cold is not what hurts the chickens its the moisture. High humidity in the winter in your coop will cause frostbite and can cause respiratory problems as you will get a build up of ammonia. Keeping well ventilated will stop this. There is posts on hereabout ventilation. Sorry its too early and I cant think of the posters name right now but they have a great thread on ventilating.

 

[Ole rooster]

Over the years the best venting I've seen is the ridge vent. Just think, from the extreme top of the vents as you have them now to the ridge is itself is "trapped" air space. The ridge vent has a drawing affect of the air no matter where it's coming in. As I said before whether anybody's listening or not, I like to vent the air up the the roof angel, from the soffit area, across the insulation I have in the roof and out the ridge. I can seal off all the other openings from weather and wind, and still have ventilation to draw the amonia out of the coop. I built my coop so I could seal it completely from the ridge to the floor whenever the weather got bad. With the sand in the coop and me cleaning every morning, the chickens seem happy and there is no odor at all inside. I've read where some are concerned with the wind blowing in the ridge and chilling the chickens. But I feel the wind from the outside and the draw for the warmth of the chickens at the ridge will counter act each other, and the vent draw will win out, that is unless a toronado hits. Then the coop won't last.

I vote for the ridge vent.

 

[LilyD]

I love it. I wish that I had made mine that big because chicken math is taking over lol. I live in Addison County and also went with the ridged green roofing. I did not seal it and left a probably 2 or 3 inch gap at the top under the roofing supports for more ventilation that will be open all the time. You could put your pop door in the bottom of the door you will be using to get in and out by making a hinged door that swings up and hitches to the top of the door when you want to leave it open. I have my person door on a totally different side than my chicken door because they tend to swarm it which makes it hard to get in and out without stepping on the girls. When you make your perches I was told to use 2X4's with the wider side for the perch so that they can cover their feet in the winter. I made a ladder in mine but then added more roosting because they only seem to use the top part of the ladder and the rest is just left open. The more roosts the better because they will fight over their favorite place on them so more choices is better. Good luck with your coop.

 

[ailurophile23]

I vote for the ridge vent too - it really seems to help air flow through without causing drafts near the roosts. Also seems to help eliminate condensation at the roof. Plus, it may allow you to leave just the front door vent open so you don't have the stronger front to back flow across the center of the coop in winter. Another thing to consider - if your nest boxes are to the outside of the coop, you may want to insulate them - on my current coop mine are to the outside and it makes it easy to collect eggs but in the deep of winter, the eggs are more prone to freezing.

 

[MadChickensVT]

Thanks for the replies

I just changed my order so that I'll be using XPS ('blue board') instead of fiberglass. I don't want any mold! Does anybody know if the XPS will trap moisture under the floor? From what I read it's semi-permeable, but I don't have experience with it in real life

It doesn't seem like much moisture should make it's way down there anyways, but you never know!

I was already planning on insulating the nest boxes but I forgot to mention it.

I'll put in some soffit vents and use some more sheets of XPS, with something to keep the chickens from pecking at it, above the roosts to provide an air channel there and protect the birds from the flowing air.

Any thoughts on how big I should make the ridge vent?

 

[Ole rooster]

The way I did mine is to put down regular screen door wire 24 inches across the ridge, furring strip to furring strip the length of the coop. Then the leaving the roof panels at the ridge back about 3 inches from center on top of the wire. Both sides. That seals out the critters that may try to come in there. From there I install the ridge cap and screw it down through the roof panel. The area you have for air venting is the heigth of the roof corrogation. About a half inch. The on the outside of the coop I install 1/2 inch hardware cloth that was push up into the screen wire to make a seal from anything getting in. Inside of the coop I put hardware cloth down the length of the coop to keep anything from getting up inside the ceiling from inside.

That has given me ventilation and no way can any critter get in the coop from that access. If you're interested I can get a few pics for ya.

 

[MadChickensVT]

Thanks Ole Rooster, I understand what you're saying so don't need you to take the time for pics. Unless you really want to

This is the roofing that I'll be using http://www.abcmetalroofing.com/panels_imperialrib.html

I'll definitely put hardware cloth over ANY venting to keep critters out. Especially the darn weasels! We had a friend who had a weasel chew through the floor of her coop and kill all her birds

which is why I'm also putting it under the floor.