Definitive Patio Advice

[chilluk]

I have searched on here and gained a lot of advice - but just wanted to check what approach best for my situation.

The soil in the garden is mainly clay but with a bit of a finer topsoil. However there are lots of Oak trees in neighbouring gardens - some quite close to where the patio will be.

I want to pave a thin area (approx 2.5m average width by 10m long) at the side of the house which will flow into main patio which will be about 5m x 9m.

There is currently patio covering the bulk of this area which has been down as far as I can tell the entire life of the house (just under 10 years) There has been a little bit of movement in the slabs in that time, and in the summer some areas see a small amount of noticable movement (as the trees drink all the water??!!) THe main area of exisitng patio needs ripping right out as some idiot decided running towards the house was OK!!

The current slabs seem to be laid on a fairly coarse aggregate dry type mix - its quite strong but a little too crumbly I guess to have been wet mix - it's about 50mm thick and direct onto the soil underneath. It has obviously hardened and withstood quite a battering from the pickaxe in the smallish area I have pulled up so far!!

My main question is this - should I use a hardcore layer and compact that?

Can I use some of the broken up existing patio, bricks, even solidified dry mix base as hardcore for the new patio or should I be getting the finer stuff from the builders merchants and whacking it to a fairly hard compacted base? I was sort of toying with putting a layer of this down and then just dry mix on top.

Will I find it easier to establish a firm level(ish) base with some finer hardcore and then do a better job wet laying the slabs?

Just looking for the best longish term approach that won't see me pulling my hair out because of excessive movement within a year or two!! I've never done a patio (done decking but want a change from that) before.

I know what the text book answer is (and if that is correct then so be it) but it seems overkill to put down 75mm hardcore and then 75mm sand/cement on top of that - but maybe that is the only way to go.

Cheers.

 

[Thermo]

put down a base of mot/scalpings and compact them. that will give a very firm base and is easy to level. Then wet lay the slabs on top of that. It wont move. Take up all the old stuff and skip it.

 

[AndyBill]

thermo , what does mot stand for?
how much would you expect to pay for this from a merchant?

 

[chilluk]

Thanks Thermo - I was sort of hoping you would be one of the people to reply!!

What thickness would you suggest of MOT? How do I ask for that at the builders merchant so I don't get laughed at MOT or M.O.T.?!!

And then when laying the slabs do I need just enough mortar to stick them down rather than a thickness that is part of the base itself? I am presuming I want the famous 3-2-1 mix?

Thanks

 

[Thermo]

put down a base of 3-4 inches of mot. You should be able to spread it quite easily with a shovel or a rake to get it at the right level and fall on it. The bedding mix should be a minimum of an inch. 321 or 421 as a mix will be fine.

You can get it from most builders merchants, should be about 35-40 a bag, or look in the yellow pages/friday-ad for small local guys that deliver it loose, will be a lot cheaper. It gets called avariety of different things such as mot, scalpings, road stone etc. The mot bit actually comes from Ministry Of Transport as they designated what was acceptable to use on different road constructions. Ask for it as letters ie M O T not as a word! Just remember it will condense down when compacted so you need to allow for that.