Patio 60cm depth to fill

[trigger01]

Hi, We have had an extension and now we want to lay a patio. I have done patios and driveways at my previous 3 houses but certainly not text book (broken flags punnered in and concreted poured around and over. Then flags spotted on top. So what most would consider a bodge but maybe due to look they have never sunk or cracked. I am very much a simple diyer but I wanted a project outside for the summer and I am quite happy digging and barrowing back and too for some excercise.
I am trying to figure out if this patio may be too much for my experience, but if possible I would like to do it so I may be asking a few, what may be dumb, questions.
Its going to be approcximately 50sqm. The ground slopes left to right and also away from the house. This is first big challenge as the far corner need to be built up 60cm (including flag). The opposite corner needs few cm fiigin out to get a 15cm depth. I was thinking of putting in a retaining wall (footings 50cm x20cm) and just filing with mot1 and use wacker every 10cm. Does this sound sensible or is there a better way of doing this? The flags (porcelin tiles most likely) will then be laid in a solid concrete bed, perhaps 5cm or more deep. Any advice appreciated. thanks

 

[freddiemercurystwin]

You can do that though there is always a danger the MOT will subside as you surmise it might. As a side note Building Control would not let you go over about 600mm if it was supporting a floor slab inside for this reason but it's a little more difficult to control when it's outside and you may have water/rain soaking through it. An alternative is a suspended block and beam base but that's comes with a cost of course.

 

[trigger01]

Thanks. Interestingly our extension has a much larger drop on the corner and the building inspector was ok with soil infill then mot/sand/insulation/slab. They did inspect before mot layer though.
The 60cm is the extreme on the corner. 80% will be less than 30cm and that include concrete and flag.
Drainage is something on my list to think about.