Base for slabs

[richie4236]

I'm planning to build a lean to at the side of our garage. It's an annoyingly shaped piece of land which isn't much use, and it too small for a shed, so I plan to cover the whole are to maximise the storage space for wheelie-bins, bikes, recycling, etc. The space is 6.6m long, and 2.7m at the front, narrowing to 1.4m at the back garden.

I would like to slab the entire area to give a nice flat floor. I've looked at a few videos on-line, and I'm confident I can do this easily enough. I do need to know a couple of things as I haven't done this before however. Firstly, I know I need to lay a decent base. One video suggested using scaplings, and going down to a depth of about 150mm. Is the right approach? Should I go deeper, or use a different base material? Also, is there a reliable way to work out how much I need, as I really don't want to end up with tons left over at the end, or not have enough to do the job properly.

Also, although it will be covered, presumably I should put a slope on the slabs for drainage? I read somewhere that 1 in 80 is recommended. Is that correct? If it is, then I should be installing a drop of about 80mm from front to back (where the nearest drain is)? That seems like quite a lot.

Many thanks.

 

[r896neo]

Your make up should be 100mm of hardcore mot type 1 then 30-50mm of mortar for laying the slabs on then the slabs.

If its your first go I would aim for 60:1. You may find if you go for 80:1 that a few low corners of flags here and there end up with small area of pooling water. Maybe not an issue if you are covering it though.

You can find good calculators for materials needed here and lots of advice on the rest of the site

http://www.pavingexpert.com/calcall.htm