Carport

[Benno]

G'day, Building a freestanding open carport-like lightweight structure (10Kg/m2 roof load) for timber storage.It is 10000beams and 6000rafters on six gal. RHS 100x100x6 posts in clay soil. How big should the concrete piles be and is diagonal bracing required for the posts and/or rafters? Cheers.

[Barry_White]

Benno

Here is an engineered carport of that size. If you want any more details PM me.

I can give you a bill of materials in all steel using "C" Purlins and Items you can buy from Lysaghts.

[Benno]

Thank you Barry but I already have the Oregon (300x100 & 235x75 from Darlinghurst Harbour warehouses) and the near-new decking from next door where they took the roof off for a second storey.BTW how big is"...triangular plate on each corner post"? Cheers.

[Barry_White]

The Plates would be about 450mm each way by at least 3mm thick. You could just use a piece 50mm x 50mm x 5mm angle. I dare say you saw the the footing mass of concrete for each post.

[Benno]

Many thanks Barry:most helpful & prompt.Cheers.

[ausdesign]

Benno, the pad sizes are determined by the area of roof they are supporting both for downloads and more importantly uplift.
The caculations are dependant on the designated 'design wind gust speed' for your particular location.
Bracing is calculated on the area & the number of supports - in your case 6 - and can be incorporated into the footing design (pad depth) with double diagonal metal strap bracing from corner to corner under the roofing iron.
Even though you dont require a building permit for free standing carports under $5000 I would look at getting structural engineer designs on both bracing & pads.
The center posts will be holding an uplift force of up to 30m2 of roof & if this lands in your neighbours back yard you'll probably wear the cost.

The timber promotion council has a small booklet "Carports & Pergolas Design & Construction Manual" which may assist.