decking subframe in metal

RobAMerc

folks,

I'm planning on decking an area on the back of our house. We are looking to run the deck board away from the house and cantilever them about a foot out over the raised "patio" thats there.

I was thinking of building a sub frame I could screw to the concrete patio to handle the cantilever.

I know wood rots over time, so in order to counteract that and for strength I was thinking of building the frame in box steel and then running the boards on top of that.

what would folks opinions be on that ?

Thanks
Rob

Steve

No reason why not if you can work out the loads. Sounds really cool actually.

I would have thought 50mm heavy wall box with at least 50% behind the fulcrum. No expert though.

CJhaughey

Sounds fine, price in hot dip galv though, rusty steel is no good for wood.
Do it once and you wil have a great job.

RobAMerc

Steve wrote: »

I would have thought 50mm heavy wall box with at least 50% behind the fulcrum. No expert though.

the overhang is only going to be about 1 meter with 2.5 bolted to the patio.

I guess I will be ordering 7 no 1 meter wide by 3.5 meter sections with batons 500mm apart. (think 3.5 meter ladders) I'll then bolt these together on the long side to make a platform which I can screw to the patio and screw the decking down onto.

this is just an idea at the moment - one of many !

Steve

As CJ said, rust proof it.

I'd say 4" x 6" treated joists would do as well.

RobAMerc

Steve wrote: »

As CJ said, rust proof it.

I'd say 4" x 6" treated joists would do as well.

I'm afraid not, the patio comes up to within 2 inches of the back door.

4*6 would mean we have to step up from the house onto the deck - also means we couldn't open the door!

btw - any ideas who would be good to do the frame ?

Steve

I know places who could make it for you - the trick will be in the planning tho.

You'll need a decent drawing before you will be able to get quotes.
You also need to consider delivery (will it fit in a van?, does it have to go through the house or other restricted access?) and also how are you going to fix the deck boards onto it?

RobAMerc

Steve wrote: »

I know places who could make it for you - the trick will be in the planning tho.

You'll need a decent drawing before you will be able to get quotes.
You also need to consider delivery (will it fit in a van?, does it have to go through the house or other restricted access?) and also how are you going to fix the deck boards onto it?

Please tell.

As for transport, the idea is each one would be 1m wide and 3.5m long. I could stick them on the roof of the car. No issue with house access.
I plan to bolt each section together to build the full platform and then drill and self tap the deck boards on.

Sample pic attached

listermint

RobAMerc wrote: »

Please tell.

As for transport, the idea is each one would be 1m wide and 3.5m long. I could stick them on the roof of the car. No issue with house access.
I plan to bolt each section together to build the full platform and then drill and self tap the deck boards on.

Sticking steel frames on the roof of the car...


Have you thought this through.

RobAMerc

roof rack - also they would each be made of 2 inch box steel so not bridge girders

Steve

RobAMerc wrote: »

Please tell.

As for transport, the idea is each one would be 1m wide and 3.5m long. I could stick them on the roof of the car. No issue with house access.
I plan to bolt each section together to build the full platform and then drill and self tap the deck boards on.

Sample pic attached

You may be underestimating self tapping into heavy wall box.

Loads of places can build them but personally I'd buy the box section and hire a welder and do it myself.

RobAMerc

Steve wrote: »

You may be underestimating self tapping into heavy wall box.

yes, I'll admit I haven't thought too much about that.
I suppose I could bolt them down, it would take some planning though.

Steve wrote: »

Loads of places can build them but personally I'd buy the box section and hire a welder and do it myself.

Me too, but its just one thing on a very long list of things I do have to do. It could be years before I got around to doing a full build.

Steve

Another option might be to consider laser cutting flat sheets and bending them into U channels.

Relatively cheap to get all the holes pre-cut as long as you can provide a dxf or similar cad file.

CJhaughey

You could just use a steel drill and fit riv-nuts.

M.T.D

Bolt a length of 50mmx50mm to the side of your box section and screw your decking to that. A lot less drilling of the steel then.