Is my decking plan sound?

[veersix]

Hi,

I'm going to be building a deck in my back garden and have attached an image of the plan for it. It is 5.6m by 3.6m and consists of four rectangles, two of 2.8m by 2.0m and two of 2.8m by 1,6m, all bolted together to make the whole deck. As can be seen in the image I have also added noggins to try to strengthen/stabilise the deck base.

The decking will be straight to the ground, i.e. not raised.

Decking Plan

decking_v1.png (18.24 KiB) Viewed 1600 times

My current plan of attack is as follows:

1) Remove an area of turf 5.6m by 3.6m to a depth of 50mm dropping to a depth of 85mm to account for a 1:100 slope.
2) Place paving slabs on a bed of sand as marked on the plan.
3) Place weed control fabric down to cover the rest of the exposed soil and then cover the fabric with pebbles.
4) Build each of the individual base rectangles that make up the whole of the base.
5) Attach the base rectabgles to each other using coach bolts.
6) Place the finished deck base on to the paving slabs, ensuring it is level along the 5.6m length.
7) Start boarding the deck.

My questions are as follows:

1) Is my overall approach sound?
2) Will sand and paving slabs be enough to support the base and keep it off ground to prevent it getting wet?
3) Have I planned in too many/not enough paving slabs to support the base?
4) Have I added enough noggins to maintain a stable base structure?
5) Do I need to add any balustrade for safety or can I leave it open (my wife would prefer it without the balustrade if possible)?

Any other advice or suggestions you have would be great too.

Thanks.

[steviejoiner74]

It looks pretty sound mate. For the perimeter you've got joists in between the posts,bolt longer lengths/full lengths to the outside instead.
You've went with 400mm centres and nothing's/dwangs. 600mm centres is ample with noggings/dwangs given the span and amount of posts you've got to stabilise.

Edit- when planning a deck go to a builders/timber yard for materials. You'll get joists in 4.8/5.4 lengths which make setting out easier and more cost affective. Same with the decking boards.

[big-all]

heeelllooo and welcome veersix
assuming in the uk
are you aware you need to keep it below 300mm at the highest natural ground point it covers
and the below 50% off the origional garden can be covered to avoid the need for planning permission

the 50% is the origional building footprint taken from the plot gives you the area off the garden
https://interactive.planningportal.co.uk/detached-house
https://ecab.planningportal.co.uk/uploa ... ldings.pdf

[veersix]

It looks pretty sound mate. For the perimeter you've got joists in between the posts,bolt longer lengths/full lengths to the outside instead.
You've went with 400mm centres and nothing's/dwangs. 600mm centres is ample with noggings/dwangs given the span and amount of posts you've got to stabilise.

Thanks for the advice.

The grey squares aren't posts. They are just the postions of the paving slabs, hence why some are in the middle of the joists. I wasn't planning on using posts, should I be?

[veersix]

heeelllooo and welcome veersix
assuming in the uk
are you aware you need to keep it below 300mm at the highest natural ground point it covers
and the below 50% off the origional garden can be covered to avoid the need for planning permission

the 50% is the origional building footprint taken from the plot gives you the area off the garden
https://interactive.planningportal.co.uk/detached-house
https://ecab.planningportal.co.uk/uploa ... ldings.pdf

Thanks for the welcome and the advice, ytes I'm in the UK. I was aware of both the 300mm rule and the 50% rule and in this case I'm not tripped up by either of them :)

The question about the balustrades was because I've seen a few decking designs that aren't much higher than a decking plank width with them and I hadn't read anything to say you had to have them, but just wanted to check I hadn't missed something.

[steviejoiner74]

It looks pretty sound mate. For the perimeter you've got joists in between the posts,bolt longer lengths/full lengths to the outside instead.
You've went with 400mm centres and nothing's/dwangs. 600mm centres is ample with noggings/dwangs given the span and amount of posts you've got to stabilise.

Thanks for the advice.

The grey squares aren't posts. They are just the postions of the paving slabs, hence why some are in the middle of the joists. I wasn't planning on using posts, should I be?

My mistake! If you are levelling paving slabs for the deck to sit on that's fine. It's only if it's raised or the ground is running away that you need to set posts and anchor the frame to them.
Low level decks don't need balustrades.

[big-all]

heeelllooo and welcome veersix
assuming in the uk
are you aware you need to keep it below 300mm at the highest natural ground point it covers
and the below 50% off the origional garden can be covered to avoid the need for planning permission

the 50% is the origional building footprint taken from the plot gives you the area off the garden
https://interactive.planningportal.co.uk/detached-house
https://ecab.planningportal.co.uk/uploa ... ldings.pdf

Thanks for the welcome and the advice, ytes I'm in the UK. I was aware of both the 300mm rule and the 50% rule and in this case I'm not tripped up by either of them :)

The question about the balustrades was because I've seen a few decking designs that aren't much higher than a decking plank width with them and I hadn't read anything to say you had to have them, but just wanted to check I hadn't missed something.

glad you have it sorted
many a person doesnt realize that any extensions garages sheds greenhouses etc since it was built or after 1947 come off your 50% allowance

[Someone-Else]

I wouldn't bother with the gravel on the weed fabric. Reason being it will only be somewhere else for seeds to grow and crumbs to collect.
Have you considered making a "trap door" for future access?

I am not joking about either, my garden is weed fabric and gravel (no decking) its surprising (to me anyway) that although there is no soil weeds still grow.