Concrete sub-base (instead of type 1) for a patio

[MSB81]

Hi all,

I'm looking to get a c.30 square metre patio laid in our garden in the coming months and have been getting quotes from a few builders / garden landscapers. We'd most likely be looking to use porcelain slabs The cheapest quote so far has come from someone who is proposing a 4 inch concrete sub-base (pumped in via a lorry from what I can gather), however I was always under the impression that type 1 should be used.

I can't find any clear pros / cons for using concrete vs. type 1 online, so has anyone on here had a patio laid on a concreate sub-base, and can they confirm if it has worked well or caused any issues down the line? To confirm, our patio would only have some aluminium garden furniture and a few pot plants on it, and would only see light traffic.

Thanks in advance for any advice on this...

 

[cwhaley]

That's the reason it was the cheapest quote. It might work well for years (unsure of the soil your way), but the most likely outcome is failure of the slabs -- sinking, cracking, heaving.... Plus you don't want to worry your whole time there about only taking 'light patio furniture' on it -- there will be one day where you'll have to drag something heavy across it.

I laid mine of a very similar size on a base of hardcore and MOT (6-8"), with a dry mix of sand and cement on top (whacker plated down) then another 2-3" of wet mix on top of that. Was a great way to get rid of loads of old broken bricks!

Far better to create a proper base of hardcore and MOT.

 

[cdbe]

I have a 30m, 4" concrete patio which I will be tiling with porcelain in the future - it's not going anywhere, but is on rock solid clay. It cost me £500 to get the concrete barrowed in and the tamped and brushed finish is good enough use till we've saved up for the tiles. I think it's slightly ironic that we'll probably end up going for concrete effect tiles!

 

[John D v2.0]

Funny that is cheaper, cement is expensive compared with aggregate alone. You'd only pay say 50 pounds a tonne for aggregate, whereas cement is say 200 pounds a tonne on top of that. So a concrete base could easily cost double in materials.
Also aggregate is easy to adjust and you just whacker it down, whereas concrete is messy and hard to adjust later.
Also aggregate is more eco friendly.