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Posted: Tue May 31, 2011 9:49 pm
by sambomartin
Hi everyone,

I've just found this web site and hope it's not too late to get some advice before I lay my "flags" this weekend.

I've excavated an area of about 45 sq m to a depth of about 2-3 inches.

I've got a load of cut stone which i now know are called flags. They are about an inch deep.

I have ordered (although i can change) 3.5 tons of type 1 to fill the area to a compacted depth of 2 inches?

Then i've ordered a ton of sharp sand and some cement to bed them in. I think i was quoted this amount based on spot bedding them, which i've since read is bad news.

It's a main thorough fare to back of house and will have table etc on it.

I desperately need some guidance on what's the best course of action from here. I've got a whacker ordered for hire this weekend also.

Any advice (esp regarding quantities or materials) would be greatly appeaciated.

thanks in advance
sam

Posted: Tue May 31, 2011 10:05 pm
by Carberry
Calculators for working out coverage for sub base and bedding layer:
http://www.pavingexpert.com/calcall.htm#focus14

Page on laying flags:
http://www.pavingexpert.com/layflag1.htm#spot

What type of flags are you working with?
It doesn't sound like you have a lot of room to work with for your bedding layer, if you have to go ahead and do it this weekend then it should be ok but it will make life a little more difficult for you laying the flags if they vary in thickness. If you have the time I would dig out another inch or two.

Posted: Tue May 31, 2011 11:04 pm
by sambomartin
thanks. thats all coming out a lot more than what i've ordered.

what do you think the minimum depth the bedding layer and sub base could be

if i took it to four inches would that help?

at the moment i'm looking at about 2 inch sub base and was going to do 0.5 inch wet mix, but reading about it that seems a bit wrong.

the bedding layer should be dry mix 10:1 sharp sand and cement right?

i was originally planning to spot mortar on flags and stick them to sub base. but it's taken a while to clear area and want to do it right.

given current situ, whats the best / and best value way to complete job.

i'm thinking now go to 3.5 inches deep, 2 inches for type 1, 1 for bedding (10:1 dry mix) - how does that sound?

tia

sam

Posted: Tue May 31, 2011 11:11 pm
by Carberry
Depends on the material you are working with, generally speaking though a semi dry mix is best, enough water in it so when you squeeze some in to a ball it holds it shape. 10-1 is fine.

I wouldn't go less than 2" or your sub base, it will depend on ground conditions though, you may have some soft spots that need alot more hardcore than that.

25-40mm for your bedding layer.

Posted: Wed Jun 01, 2011 5:48 am
by mickavalon
A 2" sub-base seems pretty pointless, is the Ground Soft, in which case you need to dig it out and layer a minimum of 4", compacted, if the grounds firm, then you may not need a sub base, but better to be safe than sorry. 10:1 dry mix is fine for heavy slabs, but if your using anything thinner than 50mm I'd go for a stonger mix, and wetter, and your going to struggle laying on a 1" bed.
Have you read any of the Site?
Aggregates aren't expensive, why are you trying to skimp on them?
You really need to have a good read on Sub-bases and laying Paving, else it sounds like your heading for a few problems.

Posted: Wed Jun 01, 2011 7:19 am
by jonnyboyentire
^What he said. Main site.