cost of building cantilevering

[goonandtell]

Approvals have come through for a development we are doing, unfortunately the plan to have the carport as a structural element has not been approved. It has to be easily removable from the main building which is hard to do if there are to do if there are heaps of supports attached to it.

The back section of the room can have a support under it however at the front it can't because it would come down directly in the middle of the driveway.

So we are faced with cantilevering, does anyone have any advice about how much something like this might cost? I am tossing up if the extra room is worth it as a return.

 

[westminster]

Why does it have to be easily removable?

I'll send my DH over. He is Macguyver and recently when we had liquid limestone paving installed he wanted to keep the pergola to shade the house so he got marine wire cable and cantilevered it off the second storey. Then cut the poles off the pergola.

Of course it's not engineer rated or anything like that, and I had a pink fit that he had drilled holes into the second storey BUT it has withstood heavy rain and high winds without destroying my house.

 

[westminster]

Oh is it because of the easement?

In WA if it's a sewer easement then we just have to have removable paving and a 2.4m high and wide opening at the rear so that it's big enough for a digger to get through.

 

[goonandtell]

Yer its the easement, that kills it, so the study above can be there but it can't have support in the places i want, we can put pavers down and even minor construction but not part of the house.

wow 2.4m wide that's decently big for access.

 

[bob shovel]

definately looks worth it, its a shame you couldnt turn it into an additional bedroom.

An enginner would most likely need certify the beam though, but span tables usually cover cantilevers too. as a simple reference guide.
IS it a tiled or colourbond roof?
What are the walls? Brick?
If 2.4m is required off the fence for access the cantilever would need to be approx 600mm, so 1000mm can be supported with a column then 600 cantilvering out. Its not a huge distance but it will need to be certifiied. An engineer might charge $500??? for his time.
Most likely steel beam with a steel column under. Not huge costs but just a bit of mucking around for you and the builder. An additional column or support would be needed in the exterior wall frame too, to hold down the cantilever

 

[handyandy]

Looking at the plans it looks like the whole study would need to cantilever. Is this correct? This would make a cantelever of about 1500mm. Not impossible but needs some substantial engineering.

I suspect that you are going to have some problems working around the stairs, as any structural elements will need to come through the space above the stairs.

Cheers

 

[goonandtell]

bob, yer we just couldn't quite squeeze the study into a bedroom, there is a mirror image just out of frame which has this room completely across the garage as a bedroom. I will check with the measurements but i think i am screwed for putting columns down as i can't shuffle the house away from the fence and the carport is already only 3500 wide.

handy, the back of the carport could be covered half way across which might help support but yes staircase didn't think of that.