Decking advice

Building deck on a slight slope. Here is rough plans.








Garage on one side, with 2 new fences going up on other sides. These are not errected as of yet.

I have read various advice on these forums but here goes anyway for my situation..

1) Joist hangers? Needed? Building frame may be a bit tricky without them?
2) Attaching side to garage - just bolt these in? Need leave a gap, how to achieve this without loosing securness to garage with bolts?
3) Amount of posts required. Only got end ones in here, know I will need more, just not sure how many do I need. Recommondations? - postcrete them in?
4) For my case may be easier to put posts in first using string lines etc ?
5) Diagonal bit, would it be better to run the supports in other direction for this bit or keep it the same as the rectangle section ?
6)With regards to fence. I know I can go 2m without planning. Boards come in 1.8 or 2.4 Should I make this fence bang on 2m from ground cutting the 2.4s or use 1.8 boards with a gravel type board below. Just not sure how close I should run decking to fence boards ?
7) Direction of deck boards. Whats the done way. Is it best to run them in direction of your slight fall ? Thinking running them in line with garage wall. ie at 90' to the support joists.
8) Lastly, planning on just using 4x2 for the frame. Should be strong enough for this size all right? Want to keep the height of decking as low as I can.

Thanks in advance!

Presumably you are aware that you need noggins as well or it will deflect like crazy?

You could build the frames in smaller bits and assemble in the gap- with a few square sections infilling the triangle.

Use a concrete gravel board beside decking?

Must you attach to the house? If so then you could use long bolts and a sleeve to get a gap, infilling with a grating . Otherwise use posts in the ground

Yes ofc know about noggins. Its just a rough sketchup. Its end of a garage, and its well well below the DPC. Just thought attaching to the wall would be much easier than using posts there as, there will be considerable amount of concrete around that area for digging. Its breezeblock wall.



An old picture of the area. All the shrubs and trees are gone. The wall behind tree is next door neighbours.

What do you mean by;

you could use long bolts and a sleeve to get a gap, infilling with a grating

Click to expand...

Thanks

You can just put on short offcut of plastic piping, pieces of pipe cut 8mm long and then thread your bolt through sandwiching the pipe between the wall and joist.

Aim to support every joist at 1.2m intervals.

id attach ledger to the house wall with a few washers behind board for air gap then bolt through.

i would usually run your joists the opposite way as typically direction of decking would go from house wall to fence due to foot traffic.

joist hangers are fine and would make your life easier.

for the fence id go with 1.8 and install concrete gravel board (will be covered by decking so dont matter which way you go)

unsupported joist span depends on what size joist and grade of timber you are using. 6x2? or if space/height limited then minimum c16 4x2 with 400 centres with support post no more than 1m in any direction. just bear in mind the higher the size the less supports usually needed.

is there a lot of weight on top like spa etc.

let us know your joist sizing and decking direction and this will determine the posts needed

Thanks.

I plan to run the decking grooves parallel to the garage wall. This way they run to the step and access point to the deck. Its just going to be an area for sitting/BBQ etc. Its a sheltered sun trap. No hot tubs im afraid!!

I would like to use 4x2 to keep the height down, due to the slope.

I have been working on other projects in garden and this one is coming up soon. When working on sketchup for a design for the frame, I have got more questions!

- Should I install some of the 4x2 runs on top of the posts or will it be ok to bolt them to the side? And if so, should I be putting joist on both sides of the post ?

- How will I attach the outside frame that is beside the side fence? (if I am attaching to side of post) Just trying to get my head around how that is going to be done. As i want the decking finish to go pretty close to the fence with few mm for expansion etc (I am planning on putting a 6" frame on the finish top with the decking inside it)

- How much spacing for noggins do I need?

Here is new plan im working on. I think I may remove the angle, as it could get quite complicated and it really does not add anything extra to it.



Other thing I cant get my head round yet is how I will add steps up to it. Either full width but with slope I cant work out how to do it. Or else have steps in the centre but again not sure how to do it with a slope.



Thanks in advance!

You have 3 joists that don't have any post supports just noggins on. Personally I would drop a couple of post supports on these to minimise any slight bounce you get on the decking as there over a 3m span. Up to you if you concrete ones in or rest on a slab . As for the steps depending on your exact height looks like you will only need one step, so I'd just dig out the slope slightly or cut step to match the slope ( depending on the angle of slope) also in regards to framing near fence , you can bring your posts in and over shoot your boards by x amount depending on what size and type of boards you have

Could I get away with just 1 post in the middle instead of 2 for them runs and add the extra 3 for them joists you mentioned?

Thanks

Ok so I came up with another design. Would this be better? Only issue I see with it, would be that I would need alot of joist hangers which would make it a bit more costly. Is this the right amount of posts or could I get away with less or more. Could I say just have one row of posts in the centre with a centre "spine" that is doubled up to posts and have the posts at the fence side still. The green shorter horiztonal joists are around 865mm in length. I may need to noggin inbetween these or not? They are 400mm from centre to centre.



Let me know, thanks!

So bit more reading and I think this design will be fine? Using 4x2 Treated. Gonna use coach bolts through the posts and the 2 joists running along side them. 2 on each post. Using joist hangers inbetween the 2 main "beams".

This be ok?

Went with 6x2 instead of 4x2.