Starting my new deck :) I need help

[Fr_303]

I'm finally ready to start my deck but this is the first time I've attempted one so I'm gonna need your help guys.
I'm planing on building 3 seperate decks one is under a porch. The 2nd is a smaller one at the front door step and a 3rd is the bigger one at the back but the 3rd one wont be till later on.

I'm gonna concentrate on the deck under the porch its going to be 3900mm x 3600mm (14sqm) (160lm). With a 20mm slope leaning to the front.
I need the deck to be 150mm at the heighest point so the decking can be level with the sliding door.

I'm planing on using 90 x 19mm Kiln Dried Reeded Merbau Decking
It has a concrete base underneath and is already covered.

I was going to have 8 bearers going across at 650mm apart. The 2 end ones will be bolted to the brickwork on the sides and the other 6 in the middle.

Is 650mm apart ok?
What size beares should I use?
How do I secure the middle one to the conctere so that they are rasied off the concrete (I do get a little bit of water under the porch when it rains)?

Thanks guys

[BustedThumbs]

Is 650mm apart ok?
Depends on what sort and size of bearers you're going to use and how much load you're planning on placing on the deck.


What size beares should I use?
Get hold of some span tables. Bunnings is selling Alan Staines' Deck and Pergola Manual which has all the info you need.


How do I secure the middle one to the conctere so that they are rasied off the concrete (I do get a little bit of water under the porch when it rains)?

Maybe try dynabolting some stirrups or saddles onto the concrete and then bolt the bearers into them.

[journeyman Mick]

FR,
standard practice is posts, then bearers, then joists @ 450 centres, then decking on top. Sizing of bearers and joists dependant on spans, spacings and strength.

Mick

[bingoshelley]

hi one thing i know about decking is make sure your holes are deep enough foundations are the key to a stable sturdy deck unlike my decks lol

[Skew ChiDAMN!!]

What Mick said. However...


I need the deck to be 150mm at the heighest point so the decking can be level with the sliding door.

...with only 150mm to play with there just isn't room for bearers and joists. :no:

More important is, what will be the minimum height; you may not have enough clearance for even a "bearer only" deck. I'll hazard to say that you want at least 120-130mm... after all, you really don't want the bearers sitting on the ground. It all depends on the fall of your slab.

650mm spacing is a tad too much for a bearer only deck... stick with 450mm as they're acting as the joists and because it's at a house entry the odds are good that at some stage hefty blokes carrying heavy items of furniture will be using it. We wouldn't like to see them to stress test your spans to destruction, would we? :;

At that spacing you'd be looking at a lot of stirrups... concrete pads may be a cheaper option. Depending, of course, on that minimum height. (It needs to be high enough to allow decent thickness pads!)

[Fr_303]

...with only 150mm to play with there just isn't room for bearers and joists. :no:

More important is, what will be the minimum height; you may not have enough clearance for even a "bearer only" deck. I'll hazard to say that you want at least 120-130mm... after all, you really don't want the bearers sitting on the ground. It all depends on the fall of your slab.

I've added some drawings I quickly did.
I'm going to use 90x45 pine for the joists ( I don't have enough room to run bearers) and was thinking to using brick pilars under each joist (3 brick pliars per joist).
Will this be strong enough?

What do you mean by concrete pads?

If anyone else can think of something it will be greatly appreciated.
Thanks

[Dirty Doogie]

Blobs of concrete - special enriched bag mix - bricks wont fit! And you'll need 5 piers per joist ie 900 centres.

[Fr_303]

Blobs of concrete - special enriched bag mix - bricks wont fit! And you'll need 5 piers per joist ie 900 centres.


I was told to use stirups instead of bricks of conctrete pliars, as the stripus will stop any bowing. I was was also told to use 150 x 45 joists instead of 90 x 45 what do you guys reckon?

Also has any one bought 45mm Stripus before ??