Confused - Diyer confused about subbase

[dbargna]

hi

I've read a lot of information on this site and wondered if someone could shed a little more light for me. I plan to create a 4x3m patio on clay soil. I think I will need some subbase - but am not sure (there will only be light traffic on the patio).

Can I just compact the clay and then lay down 5cm of sharp sand to lay the flags on, or should I lay some sort of subbase and then the sand? if I need some subbase could someone recommend something I can pick up from Jewsons/Wickes etc.


Also could someone tell me what Dolomite is - I cant find any useful info on this anywhere - but many builders (in the NE) seem to use this as subbase

thanks
david

[Rich H]

Wickes (spit spit) sell bulk bags of DTp Type 1 (perfect sub base material) for about £30 - possibly including delivery. This is slightly light for your area but if you compact it well and then allow about 1 1/2 tonnes of sand and cement you should be fine. Assuming 40mm slabs, the total thickness of all three layers will be just under 15cm or 6", which is ok for light traffic.

Ideally, take out a bit more clay and make it 2 bulk bags of type 1 - this will give you a sub-base thickness of about 7cm - perfect for a sound base for a long time to come.

[lutonlagerlout]

dolomite is a posh word for limestone,which is MOT type 1
ideal base
comes from the italian mountains the "dolomites"

why they call it dolomite and not type 1 i dont know

LLL

[dbargna]

thanks for the info guys. I've ordered a ton of dolomite and sand. Just need to start digging again. I dont have a wacker, so any one know of any good manual alternatives?

[Rich H]

A hand tamper or big sledge on end. Better to hire a wacker, though. 1 bag of sand will probably leave you a bit short.

4 x 3 = 12 x .05 x 2.2 = 1.32t. Bulk bag of sand = 0.88t (typically) + 5 bags cement 0.125t = 1.0t (and 5 kg!). This will leave you 320kg light, or 13 small bags of sand + 3 cement.

[seanandruby]

............Nothing like keeping it simple for the DIYer a?

[dbargna]

right thats pretty easy to follow - but what's the .05 and the 2.2?

my slabs are pretty old and heavy, which is the best method to lay the sand? shall I lay it all down on the subbase and then wack it down? or should I try to use the individual method here? I'll be doing all the work myself so which ever is easiest on my little back would be best. I managed to get a wacker for £25 for the weekend so I'm all set to go

[Rich H]

0.05 = 5cm = bedding course thickness. 2.2 (roughly) = tonnes damp sand per cu.m.

How you lay the slabs is largely determined by what type they are. Both methods require you to pick slabs up and then lay them down!

[Rich H]

............Nothing like keeping it simple for the DIYer a?

Thought I was!

[matt h]

............Nothing like keeping it simple for the DIYer a?

Thought I was!
short of actually do in it for the bloke, i thought you did pretty good...but tell him to read the main site.. its all there

:p :p short of actually doin it for the bloke i thought you did very well. get him to read the main site.. it is all there/ :;):

[seanandruby]

right thats pretty easy to follow - but what's the .05 and the 2.2?

If it was easy to understand then why did the person then ask the question above? was'nt slating you rich, it just seems a little long winded for the typical DIYer. I think it is easier just to tell them the final calculation they are looking for, or direct them to the calculator. it is quite daunting for some people to lay a patio for the first time and can find it hard to understand the working out. That is why the guv'ner in his infinite wisdom created the calculator page.

[Tony McC]

Dolomite is a specific type of limestone used in NE England. It is subtly different to the limestones from, say, the Peak District or the Cotswolds. The use of the term 'dolomite' in that area of England can be misleading, as it is sometimes used as a generic term for 'sub-base material' whether it's dolomite or not. I've met gangs that refer to a sandstone type 1 as 'dolomite' even though it's a completely different rock type.

[dbargna]

thanks all. I managed to dig and lay the patio this weekend and it was bl**dy hard work doing it by myself. It looks pretty good and the wife is happy. In total it cost £160 which is not bad at all. Next is to rebuild a wall....I've never done that before so it'll be fun.

[Dave_L]

£160 all in?? That's a right bargain!