Low level deck as extension to a patio

[maccifo]

Hi all,

I am new in this workshop. I am building a low level deck as an extension to a patio.

The dimensions are approx. 6m x 1,15m. I am thinking on using a frame (joists) of 90x45cm and bearers of 150x45. The heigh of the deck is around 400-500mm from the bottom so I don't want to over engineer it.

The side touching the patio will have dyna bolts and i was thinking to use the wooden posts like the picture below.

Four or five posts on the bearers and then another few next to the previous patio just in case. 

The distance from the patio is 1150mm so i don't want to put too much so it can only breathe and dry out.

Any suggestion?

Regards,

maccifo

Community manager's note: Check out How to build a low-level deck for expert advice.

[MitchellMc]

Welcome to the Bunnings Workshop community @maccifo. It's fantastic to have you join us and many thanks for sharing your project.

If the patio is concrete, then you can Chemset threaded rod into it and connect the ledger plate directly to it. Remember to leave a gap between the timber and the concrete for airflow. This would do away with the need for posts next to the patio. 

From my calculations, 90 x 45mm treated pine should be able to span the 1150 width with no need for those two bearers mid-span which you have in your plan. Or are you planning on having a cantilever portion at the front of the deck?

Are you going to use Full Stirrup Solid Stem Post Anchors to secure the posts into the footers?

Mitchell

[maccifo]

Hi Mitchell,

Thanks for the reply.

The patio is made from brick with tiles on top. Actually, there are some vertical tiles that i need to go through. That is why a thought about the dyna bolts. What length and how many do you recommend?

Also for the joists, i thought securing them with 2 screws to the ledger rather than joist brackets. Any advise?

I included the bearers for peace of mind but they seem to be over engineered so I will remove them.

As for the posts, i initially thought about timber with concrete bases (as per the picture on my post). However, if i remove the bearers and install the posts on the side, i will definitely use the stirrup with concrete footing.  What depth of concrete footing do you recommend (the frame of the deck will end up being 300mm from the ground).

Regards,

Sergio

[MitchellMc]

Hi Sergio (@maccifo),

I'd recommend Chemsetting threaded rod into the bricks to attach the ledger plate to the patio. The largest Dynabolt is Ramset 12 x 125mm Galvanised DynaBolt Plus Hex Nut Bolt. 45mm of that length will be the thickness of the timber and 10mm an air gap. That leaves you with 70mm in the wall, and I would personally prefer slightly longer, perhaps 100mm. It would be best if you placed a fixing into the bricks at least every meter.

The type of soil in your area governs the footer size. As a general starting point, a 300 x 300 x 450mm concrete footer should be sufficient. It's always best to check with your local council to find out if there are area-specific regulations.

Mitchell

[maccifo]

Thanks Mitchell,

I will do that, any suggestion as to how to maintain the gap on the ledger? Also, any recommendation of the Metric of the threaded rod?

Regards,

Sergio

[MitchellMc]

Sergio (@maccifo), 

You can either stack 10 millimetres worth of washers onto the threaded rod or use plastic spacers to achieve a gap between the ledger and wall. I'd recommend Hobson M10 x 3000mm Hot Dip Galvanised Threaded Rod, Zenith M10 Hot Dipped Galvanised Washers and Zenith M10 Hot Dipped Galvanised Hex Nuts.

Mitchell

[maccifo]

Thanks Mitchel,

It is finally completed. See pictures below.

3 x Frames installation so I can move them around myself

Threaded rods installation

Frame installed before boards

And deck with boards

Thanks for your help.

[MitchellMc]

That looks absolutely fabulous @maccifo! Congratulations on an amazing new deck, I trust you are very proud of your handiwork.

I really like your idea of creating the deck in panels. A similar system exists with our Good Times frame modules.

Many thanks for sharing your results, as I'm sure it will inspire many of our members considering a similar build.

Well done.

Mitchell

[Mathy]

Nice idea @maccifo - I’ll be interested to see how it turns out