Block Paving

[Thunderace]

Recently had some quotes for a block paved extension to an existing block paved drive, the new bit is covering areas that previously had paving slabs and grass.

The company that got the go ahead quoted :-

Excavate 'where necessary' to a depth of 250mm below existing driveway.
Level.
Lay membrane over sub soil.
Lay and compact 190mm of type one for base.
Lay 100mm sharp sand and screed.

After lifting the paving slabs they decided to use the original base - been down about 8-9 years and looked very solid - after scraping it and screeding on top.

Just wondering, is this a normal/acceptable method ? Should we be asking for a price reduction or are we caught by the 'where necessary' wording ?

[Mojooo]

well, one assumes your quoted price included the cost of the bottom base layer which they will not be using now, so you should be due a reduction in price.

[bigee]

Just a point,190mm of type 1 is a 'unusual' specification,if a normal domestic driveway then 100mm is far more usual.Also 100mm of sand?? Again far too much,will only lead to problems.

[pimpin gimp]

A typical detail we have for private driveways is this:

60mm THICK RECTANGULAR CONCRETE BLOCKS TO BS 6717 LAID IN 45° HERRINGBONE PATTERN WITH 2 STRETCHER COURSES ADJACENT TO KERBS AND 1 COURSE AROUND IRONWORK.

50mm COMPACTED SAND LAYING COURSE COMPLYING WITH BS 6677 PART 3 OR BS 6717 PART 3 EXCEPT A MAX. 1% SHOULD PASS THE 75 MICRON SIEVE. SAND SHALL NOT BE FROM CRUSHED ROCK.

225mm SUB BASE TYPE 1 GRANULAR MATERIAL

This assumes a 2-3%cbr value, not especially good ground. if you have decent bearing soil/stone or whatever under your drive you could cut back to 150-200mm sub base.

[mrmaggit]

That's a very good spec.

[pimpin gimp]

I think it's out of date now, certainly regarding the sub-base classification anyway. But it'll do. I don't do much in the way of block paved areas, unless doing permeable areas.

[Mojooo]

gimp, are you a professional block paver? if so, can i ask you loads of questions!

[pimpin gimp]

No, i'm a civil engineer that specialises in highways and drainage, we do a couple of housing schemes occasionally though which is why we have a spec for block paving.

Sorry, ask the questions though, someone here will know the answer. There are a couple of pavers on here.