How do I fix my Patio to my concrete slab?

[LucieM]

Hi Team, 

I am hopefully about to start building this patio: https://www.bunnings.com.au/slimline-roofing-3-0-x-2-4m-colorbond-hi-gloss-patio-kit_p1142541 and I note in the instructions on their website, it mentions to dynabolt it to the slab. I have a relatively new (2 months old) 32mpa exposed aggregate slab with SL82 mesh I wish to put this on.  

What size bolt would you recommend & what tools would I need to do this? Would a Ramset chemical-fix bolt be better suited? I'm worried about the wind uplifting it out of the concrete. (Reaching out to the supplier isn't really an option because they have proven difficult to get answers out of). 

Thanks in advanced! 

[EricL]

Hello @LucieM 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your patio.

Between the Dynabolt and Chemset, I would recommend using the Chemset for the simple reason that it does not put any static stress on the slab. Dynabolts work by expansion fitting and this expansion into the slab creates static stress. When a load is added into the mix it produces more stress than a standard Chemset fixing where the only load is from the patio kit and not the fixing itself.

Let me call on our experienced members @Nailbag and @Dave-1 for their recommendations.

If you need further assistance, please let us know.

Eric

[Dave-1]

Good Evening @LucieM 

Mmmm I am really tempted to suggest a third option of using a concrete screw over the dynabolt or chemset.

I like the ease with which you install them and the ability to remove them down the track without leaving the dynabolts metal sleeve in the concrete.

My only hesitation is I dont know what forces/sheer factor they have. You could have a conversation with their customer people to see if they recomend a comparable concrete screw?

I just had a quick google about if you can use a concrete screw to secure a patio roof and there dosnt seem to be any reason not to. I would still suggest to contact the company direct tho (concrete screw company if you choose to use them) The screws are located just down from the Dynabolts in Bunnings

Dave

[Nailbag]

Hi @LucieM 

Chemset as @EricL suggested. It's the far more structurally secure fastening method. It's going to need a decent hammer drill though, which I would hire being Pneumatic SDS+ It's gar quicker than standard and unless you intend in the future to be drilling into masonry a lot, its not worth buying one. You will probably have to buy a drill bit which aren't cheap. I would highly recommend a Kango 4-cut bit in the required size as thee make perfectly round holes and will drill through any red bar you might strike. Once the holes are made it's important to remove/vacuum all the remaining dust or the chemset may not take or be weaker than specified.

Regards, Nailbag