Concrete base or not???

[Ifu01307]

Hi,

I’m looking to lay outdoor porcelain tiles (1200 x 600, 20mm thick) and have had differing opinions on how to do it.

Several builders and a tiler have told me it must be on a concrete base however others have said that, unless tiles will be bearing a heavy load (vehicles driven over them) it will be fine to do on a hard core sub base and then a wet mortar base.

I know don’t know what to do, I want job done properly and certainly don’t want to skimp but equally I don’t want to spend considerable time and money on something that doesn’t need to be done, any advice would be greatly appreciated.

Thanks

Ryan

 

[norm]

Considering how most normal flag stones end up subsiding and moving about with time, it probably is prudent to go with a concrete base.

However depends how long you plan to stay in the property, if you get 5 years from the hardcore base with no issue would that suffice.

 

[joelk2]

Hardcore base. 100mm
Compacted with a whacker plate and when you've finished. Do it again.
Full mortar bed.

That's how id do anyways.

If you have Facebook, join the matipo landscaping group. Also check his videos on YouTube.

 

[Rroff]

I might be remembering wrong and there might be other factors to it but IIRC our old house the previous owner had the patio done on hardcore/mortar and after awhile some of the flag stones ended up moving and/or cracked and when we had a conservatory added they were replaced with a concrete base and held up fine for years until we moved.

 

[rexehuk]

I'm doing the same as you. 20mm porcelain coming Wednesday, 600x600 and doing wet bed laying.

This method is fine and approved, a concrete pour is the gold standard, and I'd probably go further and lay anti crack membrane too if I done that.

I'm planning on laying it on mortar bed (full not spot bedding) and you need to prime each porcelain tile with a slurry.

For the gaps, most likely settling on mapei ultracolour as it's great grout.

Also check out https://www.pavingexpert.com great resource

 

[NickK]

Just make sure you have drainage. All that surface water has to drain somewhere.

 

[dal]

I'm also doing a patio with porcelain slabs, I'm going to lay 100mm sub base wacking it down with a whacker every 2" then lay the slabs on a full mortar mix ( 6 : 1).
There is one guy on youtube who puts down a PQC ( paving quality concrete ) THEN a sub base but I cant find anywhere that does PQC so I'll just go with the sub base.

 

[Ifu01307]

Thanks for you replies, really appreciate the advice.