wooden decking diy

 Hi,

 

Looking at building a timber deck i have been looking online to see what the reccomended spacing is for the supports, cant seem to find any info for this.

 

The measurements are 14900 x 3465

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pgreen1's picture

Posts: 395

Date Joined: 20/02/08

 Have built a few decks now

Sat, 2014-11-22 11:49

 Have built a few decks now and I concrete the footings/supports in at around every 1800mm. As for the bearers that support the decking I space them at 700 mm but all this depends on what you are using. When I do mine the structure in steel with the timber decking screwed to it. I find any further apart and it becomes springy to walk on 

Posts: 926

Date Joined: 22/01/10

bunnings

Sat, 2014-11-22 11:59

 has these handiblock pre cast support footings which takes out the need to cement into the ground.  they are called Evo-crete 290x290x190

Not sure if these would be any good, anyone heard of them or used them. might save a few dollars there..

Evo-Crete is an ultra lightweight concrete, three times lighter than standard concrete with a proprietary blend of fibre reinforcing adding strength and durability. 
 
Handi Block instant floating foundations are lighter, easier, and faster to install than any standard concrete alternative, leaving you more time to sit back and enjoy your new project with pride (and without the back pain from all that digging!). 
 
Handi Blocks are a popular multi-purpose foundation/support base block for a range of home improvement projects including decks, garden sheds, landings, pathways, raised walkways, cubby houses, dog shelters and more.
 
Handi Blocks sit on the surface, requiring no digging at all
Each Handi Block is ready for immediate use preventing drawn out projects and loss of motivation as projects can be easily completed in one day!
A Handi Block will typically save you 60-70% when compared to purchasing concrete and steel posts/stirrups/brackets
Lightweight - approximately 8kg per block
Versatile and well suited to a variety of DIY projects

Posts: 459

Date Joined: 28/10/08

It depends.......

Sat, 2014-11-22 13:22

The spacings for footings depends on the carrying capacity of your bearers and joists. The heavier (stronger) these are, the further apart you can space them, so the further apart your footings are. There are Australian Standards that guide these things and these can be found in books like The Australian Decks & Pergolas Construction Manual ((Author Allan Staines).

It is worth remembering that if you do not build to the required standard and it collapsed and injured somebody, you would be liable.

Marineboy's picture

Posts: 838

Date Joined: 14/03/14

Decking

Sat, 2014-11-22 13:29

if using treated pine your main bearers should be 70mm x 70mm (35x70 screwed together) spaced 1500mm apart and posts no further apart than 1800mm..

your joists should be 90mm x 45mm spaced at 450mm centres.

If you stick to these measurements you will get no spring in the deck.

____________________________________________________________________________

 My spots are so secret even the fish don't know about them !

Posts: 926

Date Joined: 22/01/10

spacing

Sat, 2014-11-22 13:34

 will look at going 1500mm between posts and joists to be safe, looked at the below video on youtube and looks pretty simple

 

https://www.youtube.com/watch?v=wimm2yy4E8A

 

 

Posts: 926

Date Joined: 22/01/10

patio

Sat, 2014-11-22 13:36

 forgot to mention have plans into council for the area for a patio, fingers crossed as that wont leave much backyard. 

Marineboy's picture

Posts: 838

Date Joined: 14/03/14

Shane o

Sat, 2014-11-22 15:17

 the most important part of all is to make sure you square up properly right from the start and keep double checking yourself as you go. 

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 My spots are so secret even the fish don't know about them !

Posts: 388

Date Joined: 28/12/12

 Doin the same ATM iv put

Sat, 2014-11-22 16:52

 Doin the same ATM iv put stirrups in at 1500 centres 600 appart. Used 140 x45 bearers did the same out the front and its solid as a rock mate no spring at all

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 Pgfc member

joe amato's picture

Posts: 731

Date Joined: 21/12/08

use stirrups

Sat, 2014-11-22 18:18

 use stirrups as wel minimum 50mm above the ground in conc footings plus no dirt touching bearers or edge,even pretreat to keep termites out,when u cut pretrated timbers it creates access for termites only couple of mm of arsenic treatment,treat all cut  ends with creasote,seen many deckings with termites feasting,better steel beams underneath imo

 

Posts: 926

Date Joined: 22/01/10

Patio tubing

Sat, 2014-11-22 18:20

 was suggested that I use patio tubing underneath, seems like a good option.

Posts: 518

Date Joined: 04/05/08

 Im a carpenter,Marineboy is

Sun, 2014-11-23 05:57

 Im a carpenter,Marineboy is on the money although i would use 2/90x45 screwed together for the bearers.Bearers 1500mm spacing,Posts 1800mm,Joists 450mm.Keep the sand well clear of the bearers and i would recommend screwing the deck especially if bigger boards.As for pre cast footings,ground screw stirrups etc i wouldnt do it,Do it right and do it once concrete the stirrups into the ground as it would be a pain in the ass to fix later.

Pitty's picture

Posts: 161

Date Joined: 08/12/12

 90 x 45 joists 450

Sun, 2014-11-23 11:16

 90 x 45 joists 450 centres

max single span 1300mm

max continuous span 1800mm (supported at 3 or more points)

2/90 x 45 bearers (working is 1800mm spacings)

max single span 1500mm

max continuous span 1600mm supported at 3 or more points

footing size need to be a minimum of type 1 from table 3.3 as1684.2-2010 being 230 x 230 x 100 but practically would need to be deeper to pick up stirrups if cast in

bearers do not need to be screwed together but nailed at 2 x depth centres (ie 180mm for 90 x 45) with 90mm nails with two extra nails at each point of support.  Nails are to be staggered. If you use screws they need to be treated and minimum no 10 screw with 75% penetration.

timber to be aminimum of h3 and not in contact with the ground and galvanised nails required

i am a builder and carpenter specialising in large timber frame construction.  These are the requirements of as1684, as a lot of advice given above is inaccurate.  All the dimensions given change if the deck is 1m above ground level. 

PM me if you need help or further explanation

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 UBIQUE

Posts: 926

Date Joined: 22/01/10

Pm

Sun, 2014-11-23 13:14

pm sent 

DTrain's picture

Posts: 486

Date Joined: 10/02/12

I did a deck myself a few

Mon, 2014-11-24 09:27

I did a deck myself a few years back. I can give you two bits of advice.

1) The spans Pitty has posted are the minimum requirement and if you build exactly to those lengths the deck will be a bit bouncy and soft. Closing up the spacing between bearers and posts will make the deck feel more solid. I think I went with 450 between joists, 1200 between bearers and 1300 between posts.

2)I laid out all my bearers and supported them on bricks temporarily, then put in a few of the joists and leveled and squared everything. Then I dug holes under the bearers and bolted the stirrups onto the bearers and dangled the stirrups down into the holes. Once all the stirrups are in you can then double check that everything is level before you start pouring concrete into the holes.

 

Posts: 198

Date Joined: 08/09/11

insurance

Wed, 2014-11-26 06:57

Check with your insurance, my policy doesn't seem to cover a building that isn't tied down, if sitting on blocks on top of the ground and a wind blows it apart, you may not be covered. do it once and do it properly.
marrisy.