Page 1 of 1
Posted: Fri Jun 29, 2007 5:43 pm
by alien Pirate
Hi guys - looking for the eternal answers - old concrete patio (30 sq yards so don't suggest digging it up! ) 1 brick below damp course, made from 'mixer leavings' though still flat! but looks 'orrible! (with a slight slope!) with opposite side a six inches drop to the garden soil (yeah I'm one of the old English Aliens!)
Looking to smarten it up with Blocks..... or paving slabs budget of don't spend any money up to a grand...
votes on which is best maintaniance / resale in 10 years time...
also
1/ do they (blocks) need the 'recommended' 2 inches of sand below, or can they go 'nearly naked straight on the concrete?
2/ does the wall to patio join need a lead flashing to seal it?
3/ if sand is needed, what is the recommended method of edging on the open end of the blocks.
any help in making up me mind would be useful....
Posted: Fri Jun 29, 2007 6:34 pm
by Stuarty
1 Brick below damp course is never acceptable, but to reduce the height from the current surface by adding more stuff to it is just going to create more bother than anything else.
Best bet is to rip the whole lot out and do it the proper 150mm below the dpc
Posted: Fri Jun 29, 2007 6:37 pm
by dig dug dan
You cant easily block on top without a sand course to level it up. This will take you above damp course.
If you did this, and went to sell, a surveyor would pick up on it. I recently had to dig up and lower a patio for a customer because he couldn't sell his house as it came up on the surveyors report.
30yds is not a great area to dig up to any like minded contractor.
Its always best to go back to square one, rather than try to cover up in my opinion
Posted: Fri Jun 29, 2007 7:08 pm
by alien Pirate
so how far away from the wall with the damp course do you need to be before it becomes acceptable?
ps: in my heart of hearts I knew the answer -just didn't want to hear it!!
Posted: Fri Jun 29, 2007 9:22 pm
by lutonlagerlout
out it comes alien,this is a bodge free zone mate
but realistically if you bodge it now in 10 years it will cost twice as much to put right
save up and do it next year,i would have thought if you do it yourself 30 ys2 might cost £1500
cheers LLL 
Posted: Fri Jun 29, 2007 11:05 pm
by andpartington
you need to be at least 150mm or 6" below the dpc
andyy
Posted: Sat Jun 30, 2007 10:49 am
by alien Pirate
Hi - not into bodging myself - merely looking at all tactical options before doing the job - having been responsible for 150 standards and statutes in an associated area for the whole of the UK production in the past.... I spent many happy hours sorting out work arounds and best practices... ???
I've just checked the building regs and found : doc c 5.5 b if the wall is an external wall, the damp proof course should be at least 150mm above level of adjoining ground - unless the design is such that a part of the building will protect the wall....... in my case 18 inches overhang on lee side of building
the requirement can also be met by the following relevant recommendations of clauses 4 and 5 of BS 8215 1991 Bs 8102 1990 (anyone got a copy?)
5.7 As well as giving protection against moisture from the ground, and external wall should give protection against precipitation.... ...solid wall ..... cavity wall..... or by impervious or weather resisting cladding....
5.23 Cladding may be: A; impervious including metal, plastic, glass and bituminous products
Thus I would argue (on a technical {paperwork} level) that if the wall is clad / treated to a level above that of 'rain bounce' and there is a suitable membrane on to that from below the dpc - in effect tanking the wall, as with a cellar or garage pit - there would be no need to remove all the patio (no guessing how deep the excavations would go, could be three inches, could be three feet 
) but simply to 'operate' on the area adjacent the wall to provide suitable damp prevention measures... and still meet the requirements of a 'new build' on a property with sections dating back to 1820.... guess my only real answer will be to get the local building inspector on site and discuss the problem... they love people like me....... :p
Posted: Sat Jun 30, 2007 11:57 am
by bobhughes
LOL So do we mate
Posted: Sat Jun 30, 2007 3:21 pm
by dig dug dan
no matter how much legislation and regs, there is no substitute for doing a proper job!
Posted: Sat Jun 30, 2007 6:00 pm
by seanandruby
may be a bad case of false economy there.
Posted: Sat Jun 30, 2007 7:09 pm
by Rich H
Why not use a disc cutter and kango to get the concrete out nearest the wall and then use one of the approaches suggested on the main site on the following page:
http://www.pavingexpert.com/dpc01.htm
Depending on access etc this may be the lowest cost option...