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Posted: Mon Sep 14, 2009 1:49 pm
by mace
Hi
I'm looking at buying a house and the driveway on this house has been part completed. The owner says it's 4 inches of concrete on 4 inches of rubble and he's left it about 3 inches below finished level . He says his plan was to put block paving on top of this concrete.
I've had a look around this site and can't work out if this is ok to do.
Can anyone out there advise
thanks
Posted: Mon Sep 14, 2009 2:02 pm
by DNgroundworks
Is that 3 inches below DPC?
Posted: Mon Sep 14, 2009 2:24 pm
by mace
it's 3 inches below the curb - he said about putting an inch of sand down then the paving on top of that to finish level with the curb once it's been dropped
im not sure about a dpc but you have to go up some steps to the front door so i guess its well below the dpc level
Posted: Mon Sep 14, 2009 8:08 pm
by lutonlagerlout
100mm of type 1 is recommended,if you put sand on top of concrete it will become waterlogged.
laying detail for rigid pavement is
here
ATB LLL 
Posted: Wed Sep 16, 2009 8:48 am
by mace
ok thanks
are you saying that block paving on concrete isn't an option ?
Posted: Wed Sep 16, 2009 9:22 am
by mickg
it is an option to lay block paving on top of concrete but you need to drill 50mm holes in the concrete for drainage at approx 600mm centres in all directions
you need to fill the holes with clean hardcore which is well compacted and lay a geotextile layer over the total area of the concrete and then cover the geotextile layer with the grit sand laying course
Posted: Wed Sep 16, 2009 9:38 pm
by mace
hmmmm, crazy paving it is then !!!
thanks
Posted: Thu Sep 24, 2009 8:14 am
by jay-Manor Driveways
this isnt rigid paving though its just block paving on a concrete base which is done all over the country on carp parks to patios
it will be fine to lay paving on top of this and will be as strong as anything else and with good falls wont be any side affects
sounds like you just need a paving company to come and lay it buddy which will be no big drama and shouldent cost the earth
Posted: Thu Sep 24, 2009 4:32 pm
by msh paving
mickg wrote:it is an option to lay block paving on top of concrete but you need to drill 50mm holes in the concrete for drainage at approx 600mm centres in all directions
you need to fill the holes with clean hardcore which is well compacted and lay a geotextile layer over the total area of the concrete and then cover the geotextile layer with the grit sand laying course
If you drill holes like that in concrete it will break up all over the place,block paving laid correctly is impermeable so the is no issue with drainage,myself and many other contractors have laid block paving on a lean mix concrete or base course asphalt with out this drilling holes idea,the geotextile over concrete will do nothing apart from wasting you cash MSH
Posted: Thu Sep 24, 2009 5:07 pm
by mickg
don't shoot the messenger, I am only quoting what Marshalls technical advise to do, the goetextile layer is to stop the grit sand laying course from migrating into the drainage holes
I have also laid block paving on a lean mix base but we know what we are doing where as a DIY person may not
Posted: Fri Sep 25, 2009 5:52 pm
by jay-Manor Driveways
seems marshalls know nothing either and there the proffesionals lol broken concrete base and wasted tarram lol
but then again those office bods have never been onto a site in real life so cant blame them can we??? lol
Posted: Fri Sep 25, 2009 6:20 pm
by mickg
If the ideas is no good why would Tony list it on the main site ?
http://www.pavingexpert.com/blokbase.htm
about half way down the page under the heading "Vertical cores"
Posted: Fri Sep 25, 2009 6:47 pm
by msh paving
Quote
"It should be noted that we have NEVER used this method on a commercial project, and cannot vouch for it efficacy on all jobs, but, on the few occasions when we have used it on residential driveways, it has worked well.
The holes are typically drilled at 2 metre centres, and once the core is removed, they are filled with a clean gravel which is compacted down with a punnel. The entire base course is then covered with a separation membrane, usually Terram 1000,"
Marshalls, probilly got the idea from this page on the site but as Tony say's he cannot vouch for its efficacy MSH
Posted: Fri Sep 25, 2009 7:10 pm
by mickg
the original poster never mentioned commercial block paving either ?