Sunday, April 10, 2011

Building a Chicken Coop, Part 1

Part 1 Part 2 Part 3 Part 4

My wife and I have always wanted chickens for eggs. So this early this spring we decided to build a chicken coop and run in our back yard. We have hawks and dogs living nearby so free-ranging really wouldn't work.  So we decided to build a strong coop and fully enclosed run to protect the flock.

This chicken coop was loosely based on the ubiquitous 8x10 garden shed commonly available at home centers either in kit form or fully constructed. "Loosely based" might be an understatement, since the only real similarity is that the building is 8x10 feet in size. This turns out to to be a pretty convenient size for minimizing waste with dimensional lumber and panels. Maybe this is why its so popular. Half of the building will be used to house and store their feed, water, and any other chicken accessories, while the other half will be the coop. I planning on automating the feed/water so that the chickens can be sustained for a week or more without intervention. I'd also like to eventually build an automatic chicken door. But I can't be getting to ahead of myself :)

I also designed this coop to be built fairly close to code, as practice for housebuilding (even though code is a pretty pathetic standard in my opinion). The studs (2x4's) are 16 inches on center (oc), and I will be using tarpaper underlayment for the roof, tar paper over the sheathing, as well as aluminum drip edge on the roof. Any doors and windows will have real headers, as well. This will add to the cost and time of construction. The jury is still out on things like flashing for the penetrations, and I don't plan on on the roof framing being up to snuff. There is no requirement for structures of this size to be code built where I live. I was debating on using housewrap, but tyvek is overpriced for this application, and even the cheap stuff is twice as expensive as the tar paper.

First we cleared the leaves and plants in the way and decided exactly where we wanted it. Our back yard has a pretty decent slope with some variability at the site so we did some light soil grading with a rake and shovel to even things out a bit. The 2x6 rim joists were tacked together first to square up the floor and then placed on the blocks. Once square, we adjusted the concrete corner blocks by digging out the soil underneath until they were close to level. A couple of CCA scraps were used on one corner to shim the frame to plumb.

We framed the floor with pressure-treated (CCA) 2x6's. Pressure treated wood is necessarily poisonous to prevent organisms from eating it. It also it highly corrosive to bare steel, which is why I used galvanized nails. We attached 3/4" OSB flooring over the joists. It has tongue and groove construction that helps with strength. OSB (Oriented Strand Board) is an alternative to plywood which is significantly cheaper but offers the same sheathing and flooring performance. Where we live it is about one-half the cost of plywood. It was also secured with galvanized nails since they penetrate into the treated lumber. I put one about every 10 inches.

On to part 2!


finbar hannaford said...

you should or used joist hangers on the floor joists, and your spacing between the joist are too big they should be 400mm/16" centers spacing for maximum strength very good though :)

Glenn Hackleman said...

Yeah 16" OC would have made the floors sturdier, definitely. However for the application it worked out okay, the chickens don't weigh much :)