Foundations

I am building a car port attached to a brick garage it will have four 7"by7"posts with 7"by7"beams supporting a slate roof,overall size will be 5 mtrs by 4 mtrs.What size concrete foundations would you recomend and what type of fixing to same.Frost is not a great problem.

I would use a grade beam. dig down to solid earth and construct a form for a sub-grade footer 18" - 24" wide , 8" - 10" thick. Then form a curb or plinths to set your posts on. 10-12" above grade is recommended. This can be done in one pour or separatly , just be sure to lay in some re-bar or j-bolts to join the two sections if poured separatly. Simpson strong tie TM make several rust resistant base connectors , sold at big box stores in US. Piers could also be used but I would not recommend them for this ap.

I like the name, beerfreak.

You should be sure to get some local advice as we are Yanks for the most part and we do things a little differently here.

Good luck with the project.

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Thanks for feedback,what is difference between plinth and pier,a diagram would be great.
Smashing site this.
All the best
John.

By plinth I'm mean a small conical base that supports the post and is formed atop the concrete grade beam. A pier may look similar above grade but would go sub-grade to a footer (below frost line). If your using pressure treated wood the plinth/pedestal is often eliminated, but I would not recommend doing that. Sorry I don't know yet how to load diagrams.

Here's my version of a plinth. It is resting on an 18" thick footer which you cannot see in this picture. The pin in the middle of the plinth is poured in and keeps the post from shifting. I actually welded a stainless steel cap on this plinth before setting the timber post upon it - so termites couldn't make a sneak attack through a potential crack in the plinth. Yes, the stainless would probably be considered overkill.

Thanks for the replys,I am looking at 10"thick concrete base approx 2ft square with an 8" high plinth.
I had thought of a 2" wide galvanized strap moulded into the footings and secured to the posts with lag screws.
I am using green oak from Lord Inglesfields estate [very grand].
Termites thankfully are not a problem and our little woodworm only penetrate sapwood.