Low-level composite deck

[oninpena]

Hi,

I am planning on putting a low level composite deck on my alfresco.  I have attached some photos of the alfresco where I plan to put the decking. 

I plan to build it on top of the concrete and apron, and part of the deck would also be on the soil at the side of the house.  Please see the last photo/drawing of where I plan the deck to be (second to last photo is a render of the alfresco area without deck)

Questions:

1. In the first photo below, there is an opening/pipe/drain on the concrete apron.  Can I build the deck over this?  Is there going to be a problem?

2. On the third photo, you can see the part that has no concrete, what can I put here to support the deck? Can I use pavers and try to level it with the concrete apron?

3. I've read a lot of discussions on raising the joists from the concrete.  The height of the internal floor from the alfresco floor is 140mm.  If I use 90x45 TP + 23mm deck (Ekodeck) that leaves me with 27mm gap.  Can I use angle brackets to raise the joists to ~27mm?

Thanks you in advance to those who will respond!

[MitchellMc]

That looks pretty adequate, @oninpena. What size timber are you going to use for the joists?

Mitchell

[oninpena]

@MitchellMcI plan to use the 90x45 since that is what I often see suggested here.  Plus my internal floor is 140mm, so the joist plus the deck plus the angle bracket should make it almost level to that.

[MitchellMc]

Your layout looks great for 90 x 45mm timber. Well done digesting the information provided by the community and coming up with an adequate design.

I'm looking forward to following along as this is shaping up to be a fantastic project.

Mitchell

[oninpena]

Ok, changed the orientation of the boards to take advantage of the 5.4m lengths.  Each section/picture frame will have 1.8 m boards.  Have to go with double breaker boards to be able to cover the length of decking that I want.

[oninpena]

Hey @MitchellMc , got some questions again.

The longest side of the deck is going to be 6.28m, so I need the bearer to be slightly longer than 6m.  But looking at the available lengths for the 90 x 45 TP, the longest is 6m.  So I was thinking about just using 2 x 3.14m instead.  What would be the best way to connect the two?

Also, how can I connect the corners of the bearers?

[MitchellMc]

Hi @oninpena,

Both lengths will be individually supported, so joining is not essential. The easiest way would be to cut a short 500mm length of timber to be placed on their front face. Screw through this timber into the ends of the two lengths.

The corners of the bearers can be joined by simply screwing through the side of one timber into the end of the other. Or you can just use a joist hanger and fold the extra wing over.

Something like this Zenith 14G x 75mm Galvanised Type 17 Batten Bugle Head Timber Screws - 25 Pack should be suitable for both applications. You could go with a 100mm for the corners, though.

Mitchell

[oninpena]

thanks @MitchellMc 

got some more questions around the pavers.

1.  so from my understanding I would need to flatten the soil (which is clay btw), then put the weed mat on, then put the gravel (or is it road base?), then lay the pavers on, is that correct?

2.  Do I need a compactor to prepare the soil and gravel/road base? Or is a tamper enough?

[EricL]

Hi @oninpena

Using a tamper should be sufficient when preparing the soil. Please make sure that the fall of the soil is away from your fence and away from the deck. Then place the weed mat down. You then place the paver on top of the weed mat and surround the area with gravel. Placing the paver on top of the gravel is not recommended as you will not get a flat surface and could cause it to settle at a strange angle.  

Please keep us updated with your progress, we look forward to seeing the start of your deck build.

If you need further assistance, please let us know.  

Eric

[oninpena]

Thanks @EricL !  Yeah, can't wait to start on it too, just need to double check my measurements and check that I've got every little detail that I need.

[oninpena]

Hello again @EricL and @MitchellMc ,

Just a few more questions before I go and buy all the stuff I need:

1.  For the angle brackets, what screws can I use to attach to the timber and to attach to the concrete?

2.  For the joist hanger, I plan to use the Pryda joist hanger .  What nail or screw can I use for this?

3.  For the pedestal feet on pavers, is the positioning below adequate (the black circles represent the pedestals)?

4.  The area in the red box below is the concrete apron that slopes towards the soil, I'm assuming I can use the angle brackets on top of wedges (to make the bracket level) bolted to the concrete?