Big carport

[Desie]

Hi folks

I want to put a big timber car port up and everyone I talk to say it's not possible. I don't understand the major issue.

The span is approx 24ft wide by just over a car length, probably about 10-12ft.
I would like to do it if possible with four corner posts of probably 100mm sqaure section with maybe 4x2 for the upper frame and a 3 sided 4x2 lower frame for stability. I was then planning to drop in 3x2 struts on which to mount the lightweight corrugated plastic roof.

The 25ft span needs to be without a middle post at the front edge due to turning circles etc. There is an option though to put in a middle post at the back and possibly a middle post to form a cantilever for the roof.

Please tell me if this is possible.

 

[iangh]

over 30 sq metres needs the planners for a 'car' port ( open two sides)
24 foot span is huge , you will need incredible support for that, u needs a structural engineer to prevent danger to all and sundry, especially your car

 

[Desie]

Thanks Ian

I wasn't palnning on having any closed sides to the port. It would literally be a plastic roof on 4 legs. This is regarded as a temporary structure as far as I can gather. Is this not right?

Regarding the support I don.'t understand why the structural engineers need to be consulted. All it would be is a 24ft 4x2 secured with heavy bolts and a metal seat. There isn't a massive amount of weight involved. The heaviest weight is the 4 posts which will be standing upright and supporting themselves but concreted into the ground by about 18 inches.

Can you explain why there is a danger issue?

Thanks

 

[JohnD]

...All it would be is a 24ft 4x2...

If you can buy a piece of 4x2 24 ft long (which will not be easy) it would probably break under its own weight when laid horizontally and supported only at the ends.

Reconsider your desire to have a 24ft beam with no intermediate support. Or be ready to spend a lot of money.

 

[Desie]

Thanks John
Never even thought about that.

How about this for an idea.
Imagine a 24ft x 12ft square as I was planning with a middle support post at the rear and a central support post to give the central weight support as a cantilever. You would end up with 3 main support beams from front to back but the central one would be a cantilever.

That way my turning circle in and out would only be partly restricted.

Would this work?

 

[^woody^]

You problem is not only the the large span, and the weight/size of the sections, but also the wind lift on the roof - which will push and pull it (upwards and sideways). And also an allowance for snow loading. It's not just a case of using stonger bolts - they wont stop a timber section bending or flexing

Carports do require planning permission, unless they meet your permitted development criteria (size/location etc). If you have used up your PD allowance, then you have to apply for permission

 

[Desie]

But would the cantilever work?

 

[denso13]

u needs a structural engineer to prevent danger to all and sundry, especially your car

You problem is not only the the large span, and the weight/size of the sections, but also the wind lift on the roof - which will push and pull it (upwards and sideways). And also an allowance for snow loading. It's not just a case of using stonger bolts - they wont stop a timber section bending or flexing

The span and area of this really needs proper design. Cantilevers can, and do, work but don't guess at it.

 

[big-all]

heeelllooo desie if i was building a coverd area your size it would be approximatly half a ton
24ft wide would require around 30 sheets of corrigated plastic of 600mm x1800mm because of overlaps
you try lifting 10 sheets they are heavy

you then need a minimum of support at the edge and one central of each sheet these can be 2x2" so that 24ft of 2x2 x 6 lengths thats 150ft of 2x2

then you have 4x2"every 6ft accross the width 12ft x5l = 60ft 4x2

plus the edging of 6x1 timber =36ft

you would also have a post at each end of the 4x2"plus one central so thats 15 posts

so exluding posts your shopping list is

30 sheets plastic
150ft 2x2
60ft 4x2"
36ft 6x1"

is that heavy you can decide

obviously if its a car port it would be slightly different as you would need 8ft between supports to drive through and it may be attached to the house fo support but you get the idea

 

[masona]

Well if you don't mind paying out and it's not cheap, a carport with no supports, System 2000 Canopy

 

[^woody^]

Thats a good system.

But I can't see the point of parking the car on top of the roof - surely it will get wet?

 

[Static]

24ft in timber.. mmm LOL your front end member would be something like 100x450dp (4x18"), would be easier to make a frame from steel, corner post, perimeter members and some cross bracing at the ends, then do the roof in loose. Or put a post mid span on front

 

[masona]

Thats a good system.

But I can't see the point of parking the car on top of the roof - surely it will get wet?

Not if you put another roof on top

 

[Thermo]

but then youll have another mini metro on top of that!

 

[AndyBill]

yeah but then you could put another roof on that.....