What posts for a chook pen?

JojoC

I am building a combined outdoor chicken coop and run.

Timber framed. Overall dimensions are 1600 x 4200/4400mm x 2000 tall. Primarily mesh with a colorbond roof.

The 'coop' part will be raised (so chooks can access the ground under) and enclosed. It take up a space at one end being the full width (1600) x 1000mm of the long length of the run. So the balance of the 'run' part will be full width (1600) x 3200/3400.

The timber corner posts will be either 100 or 125 square, set on stirrups set into 350 diameter x 600 deep concrete.

Need advice on how many 'corner' posts I need.

• 4 (literally one at each corner)?
• 6 (one at each corner of the overall structure plus two more at the 1000m mark where the 'coop' part ends)?
• 8 (ie 4 along each long length at the 0, 1000, approx 2600 and 4200 marks)?

Obviously there will be additional uprights and horizontal beams as well to support the overall structure and mesh.

Expert advice would be greatly appreciated!

JacobZ

Hi @JojoC,

Is it possible to get a quick top-down sketch showing what you're trying to achieve. I think I have a good idea, but seeing your plans on a page will certainly help to make sure our thinking is aligned.

While what you are proposing is certainly possible and the materials you are planning to use seem good, roofed structures, such as pergolas and in your case, chicken coops, still have legal requirements for construction. This is mainly because anything with a roof is subject to uplift, which is essentially where wind gets underneath the roof of the structure, which then acts like a sail. The wind loads applied to roofed structures can be surprisingly strong and in situations with strong wind, wind can and has pulled structures out of the ground and thrown them, causing damage to property and injuring people. So, it is important that anything with a roof is built to the relevant standards and complies with the rules of your local council. For this reason, I would suggest you check with your local council to see what your requirements are in relation to this construction to see if you require building approval, or if this is considered exempt in your location.

With all this being said, the two main things that would need to be considered when deciding how many posts you need, is the roof and the elevated floor section. This is because your posts must be spaced adequately for the span of your roof beams and the bearers and structural framing for the elevated floor.

Of the options you've suggested, I'd be inclined to go with eight main posts: one at each of the four corners of the coop and two between the coop and the end of the run and two at the end of the run. This ensures the spans for the roof beams and elevated floor are reduced and that there are as many foundational anchor points as possible.

You'd then just need to ensure that the roof beams and rafters are a suitable calibre to span the distances between these posts. Unfortunately, the span tables for this are contained in the Australian and New Zealand standards for timber framing, which I do not have access to, so you may need to speak with a draftsperson, builder or carpenter for their assistance with a design.

Let me know what you think and if you have further questions, I will certainly do my best to assist.

Jacob