Raised Decking - How much support?

[jonesy1234]

Hi,
Newbie question - Hope you can help?
I have an existing decking that was in our house when we moved in, this is already raised off the floor and what I'm attempting to do is to remove the decking boards that are in place, extend the frame work (support) to extend the decking area as it really isn't sufficient space at the moment.
The question is, how much support is needed? The section that I'm extending by is approx a meter and at the moment it is just grass area. Would you say to concrete the support posts in the ground? or to bolt the post supports into concrete blocks placed on the earth?

Any advice grately appreciated

Cheers

 

[WabbitPoo]

If the original frame is rock solid, and if you bolt to it strongly, i can't see a reason why you can't just do the latter. Or compromise and put a couple of your supports deep into the ground for lateral stability (that's what I'd do)

 

[Thermo]

posts concreted into the ground, most stable you can get.

 

[jonesy1234]

Cheers

I think I'll concrete them in for peace of mind, I dont think they'd move if I did use blocks but better to be safe than sorry....

Next question then - how many support posts would you use? The width of the decking is about 6 meters, and the section i'm extending by is 1 meter, i'm going to add 2x 6m joists so will need two rows of supports, i'm just not sure how many to use for this area?

Cheers for you help

 

[WabbitPoo]

There's no set answer, but, as a test, try putting your joist on edge up on two bricks and standing on it. That way you'll see how it flexes. Next put another brick half way between - see how it flexes now. That way you'll get a feel for how bendy (or not) wood is. If the existing deck is fine, replicate what's there.

 

[bathjobby]

Haven't you already got all your answers in front of you i.e. if the existing deck is ok, just copy its construction.....

 

[hitbit]

Assemble the new frame, bolt it to the old frame ( if it is in sound condition ).
Use temporary timber legs like 2x2 from frame to ground to ensure new frame is level. Pick your spots, remove any grass, dig down about 3 inches use a little gravel, you can make a mix of gravel and cement if you like, cover with a flagstone then mount your permanent supports ( legs ) between the frame joists and the flagstone. Do ensure all is level before you mount the decking boards. This system is simple and allows for adjustment.
ps. Set the joists at 400 mm centre and mount some noggins between them.


best of luck

hitbit