Raffs Low Deck.............

Gday boys & gals,

Just started building a deck and thought since I have learnt from other DIY building tips from this website, I thought I would share my experiences for those considering a new project.

A quick background-

Im not a tradie, have run of the mill tools and would consider my DIY abililty about the average.

The deck area is 7m x 5.7m and I am working with approx 240-250mm clearance. 90+90+20mm should leave me with at least 40mm clearance below the bearer.

Im using 90x90 F7 H4 treated pine for bearers bolted straight onto stirrups and 90x45 F5/F7 treated pine for joists at 440mm centres. I plan to use 140mm merbau with stainless decking screws. My budget is approx $3600.

Appreciate any tips or advice as I progress, likely take around about 4-6 weeks, im doing it entirely on my own and only really have the weekends to work on it!

The beginning-

I began recently by planning the location for the holes. I have approx 250mm to work with to bring me up to floor height. I also have 50-100mm of compacted crushed rock below that for drainage and to keep any weeds away whilst I was doing the rest of the garden over the last few months.

Like most of my projects I tend to over engineer most things but I would rather give it too much than not enough. I went for a simple 1000mm x 1000mm grid so the bearers are approx 1000mm apart and the stirrups are also at 1000m apart. (The 1st bearer placed at 700mm to the next to make up the 5700mm). This left me with 6 rows of 8 holes- 48 holes to dig- yippee!
http://members.optusnet.com.au/~slrafferty/mypic113.jpg
I hand dug the holes 350x350 and 500-600mm deep. After about 20 holes and two broken spades and a bent crowbar (solid clay is a biatch) I hired a hydraulic post hole digger ($110 for half day). Digs quickly but not as neat as my hand dug holes and also not as accurate in placement! I find the auger bit jumps around before it grabs- maybe chocking the wheels would help. It also pulls in the top of the hole as you lift the bit out making the hole entrance unnecessarily wide- see holes left side holes in above pic. (Ive also used a 2 man auger before for another project and in solid clay it is hard dangerous work to get down 500-600mm!)

After digging the holes and cleaning out a heap of dirt I went about sourcing the 90x90 and 300mm Pryda post anchors. I used a small hardware store in Ferntree Gully which had the F7 KD 90x90 at around $12/m and nice dry straight lengths. Obviously 7m is a bit long for one length so used 4m & 3m lengths.

I found a bargain centre in Kilysth that sound the Pryda engineered post anchors for $4 each. Bunnings had them for $8 each.

I lined up each bearer over the holes and 106 bolts later (M10 120mm bolts -$110) the post anchors where attached. After advice from an experienced deck builder (thanks Utemad!) I joined the bearers over a hole each having there own bearer. I widened the holes to give more space for both anchors- more digging!
http://members.optusnet.com.au/~slrafferty/mypic115.jpg
I then chocked the bearers to make sure all was level and now ready for the concrete.
http://members.optusnet.com.au/~slrafferty/mypic116.jpg
I needed 2.5 cubic metres! So mini mix was definetly the go. $440 for 2.5 delivered. Materials to mix it myself would have been approx $400 so it was a worthy investment. 38 bags of cement aint cheap!

I borrowed a mate for this and around 30mins with 2 wheelbarrows and the job was done. I made sure it was tightly packed and slightly above the surrounding ground and will leave it for a week to dry.
http://members.optusnet.com.au/~slrafferty/mypic117.jpg

Plan to start the joists next week, stayed tuned................................


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