Porcelain Patio - Getting Myself in Knots

The internet is a great and terrible thing!!!

I’m planning on doing the patio myself - all the time of the world, not afraid of hard work - but I’m getting myself in knots with the sub bases for the porcelain patio.

What I’ve researched is that you need 100mm of MOT; 50mm of a 1:12 lean mix - whacked; 30mm sand:cement 1:4; and 20mm flag. The Paving Expert and Greentop Landscape talk about how porcelain must not be laid on an unbound/flexible sub base - hence the weak lean mix. This makes a lot of sense to me. But on the brockstone YouTube he uses a dry mix to bring up levels if needed. And I really like that guy and the stuff that they do.

The problem is that I have 160sq m of patio to lay; and my side access is the size of a wheelie bin. That’s 35 tonne of mOT to bring in by hand - which is fine to do.

My question is really about the 50mm 1:12 lean mix. If I lay that myself I’d need about 8 m3. And if I’m gonna do that I might as well get concrete pumped in and lay the porcelain on with adhesive.

Any advice? Appreciate everyone taking the time to read this. Thank you.

I always lay them on a concrete/lean mix surface. I bed them full on 3:1 mortar but you must make sure you use a trowel and scrape the entire back of the tile before bedding on a full bed of mortar.

I was asked to relay a triangle shaped patio that some contractor did. The tiles were loose but level !!, dot and dabbed, and the back of the tiles hadn't been scraped with mortar, hence why they detached. So I mixed up a really runny 3:1 mortar mixed, poured it on the tiles and used a squeegee to move it about so it ran into the joints. Then the next day, I poured brick acid down, swept it about and hosed it down. Turned out to be one solid flat patio.

You can buy those big levelling discs that the corners of the tiles sit in to avoid bedding them but all I know is that they're costly.

I use the quarter cube tubs of mortar from my local fencing supplier. And yes, easier to get a ready mixed load in for the base.

Thanks so much for that reply. Will take your advice about the 3:1.

Can I ask again about the laying surface you use.

I presume 100mm MOT
What do you put in after that exactly?

Thank you.

Sorry, hadn't been on for a while, just very busy with work.

I always whack down 100mm mot hardcore and then 75mm c20 concrete. Then anywhere between 25mm to 40mm 3:1 mortar.

Just one golden rule, when using mortar below damp proof course or on a house roof, it's always 3:1 mortar.

A mate did his hardcore, then screeded sharp sand and cement, I think 8:1. Then full bed mortared the tiles onto that. Apparently he saw this on Youtube, that is not the way I've been shown and it's not the way that I use.

To karlitob1983
I'm in a similar situation in regards to the MOT and Lean Mix.
I've seen John lay on both a wet mix mortar and a dry mix.
I've seen him use the lean mix of 15/1 on top of t he MOT (I think).
Is the lean mix dry? Can you buy it already mixed and what does it consist of? Just sharp sand and cement?
I'm only doing a 20m2 area but still have to barrow it through the garage and kitchen
I hope someone can add to this.
Thanks in advance
Andy

Yes, sharp sand and cement dampened enough so when you squash it in your hand, it forms and remains in a ball.

Hey OP I'm still wqorking on mine
I have to say the the top pation area base including the lean mix has been down for 10 months now and it's stil perfect for laying the porcelain tiles. I did protect it over the last winter with plastic sheeting.
I've been working on the lower pation base this year and that is now ready for the MOT and lean mix base (hope to get that down before this winter).
John has been an absolute hero in my eyes with his youtube videos. I hope next year I can post some photos of my finished project.
My back and other health issues has held me back this year but I can wait to see this finished.
Good luck and maybe you could post some pics too.
Andy