Low profile timber decking over concrete

[Dilanka]

Hi All,

This is my first post here.

I am planning to build a timber (Merbau 90x19mm) deck in my alfresco area. Deck will be over levelled concrete slab (which is part of the house slab) plus concrete pavement. Maximum height I can get near the house is 9.5cm as I cannot cover weep hole in the wall.

Main issue I am having is the concrete pavement since it has 70cm slop over 1m. 

 

Proposed Structure:

Joist: 70x45mm Treated Pine in the slab area , 90x 45mm & 140x 45mm Treated Pine in pavement as shown below.

Cross section:

I am planning anchor timber joist to the slab using "L" shape plates. But, not sure what will be the best way to mount the timber in pavement area.

Can you please give your valuable thoughts/ comments on my proposal & a solution to mount the timber joist in the pavement area?

Thanks

Dilanka

[Jason]

Hi @Dilanka,

@MitchellMc will be back on the site tomorrow (Friday) to assist you. Please let us know if you are in a hurry for this detail and I can tag other members who might be able to assist. 

Thanks,

Jason

[Dilanka]

Hi @Jason 

Thanks for your response. That's alright, I'll wait for @MitchellMc .

Dilanka

[MitchellMc]

Hi @Dilanka,

A would suggest an initial gap of three millimetres between Merbau decking boards. Once you screw in the first board you can tap three millimetre thick nails next to it to create the spacing before laying the next board. When the next board is fixed into position you should remove your nails and continue the process across the deck. The boards will shrink over time and the gap which was three millimetres will increase to around five millimetres.

Between the middle of one joist and the next a spacing of 450 - 600mm would be suitable.

A gap of ten millimetres between your last joist and wall of your house would be sufficient. It just needs to be large enough to accommodate swelling of the timber and water drainage.

Please let me know if you need further information or have questions.

Mitchell

[Dilanka]

Hi @MitchellMc 

Thanks you so much. This will be really helpful.

Regards,

Dilanka

[Dilanka]

@MitchellMc  @Jason 

I completed the deck. Only pending is oiling which I need to wait for 4-5 weeks. 

Thank you so much for your assistance.

Regards

Dilanka

[Jason]

Congratulations @Dilanka, it looks fantastic. I'm sure you will enjoy entertaining on that space with friends and family for many years to come. I have featured the deck on our Project Gallery so that other members can get inspired by what you have achieved. Thanks so much for coming back and showing us the finished deck.

Looking forward to seeing what you tackle next. 

Jason