We recently paid the best part of £10k for 110sq/m of block paving/walling comprising front driveway, side walkway and rear patio. This was completed in March 2014 and the job looked fantastic, no issues whatsoever, and we have a 5 year guarantee with the company.
3 months on, there are dips where the cars are parking, not major dips, but certainly noticable and water is pooling in around 12 spots on the driveway, where 3 cars park overnight. I understand all block paving will move very slightly etc, but if it's done this after 3 months what concerns me is following bad winters and long term.
Also, quite a few of the blocks have chipped where it looks like there may have been air bubbles or defects, a pillar for the walling completely broke in half, the mortar on the joint where it broke is very yellow, sandy, and crumbles easily.
The company have told us that 1. block paving will dip very very slightly where cars are, and that nothing can be done about it. Their rectification to the 12 dips was to turn up, remove the blocks where the 12 dips are, pour cement (yes, they poured cement) - i wasn't at home at the time and this is what the wife told me they did, having checked the cctv they actually did, and then re-screed/lay the bricks on top, it's certainly got rid of the dips, but to me that's just a quick bodge that isn't going to last long term. I've pulled them up on this
"rectification" and not received a response as of yet.
They have also told us that the wall pillar is fine and the mix is fine and that someone must have driven into the pillar to break it, we have CCTV and no-one has driven into the pillar, complete nonsense.
I think it's worth pointing out in their defence that they did use good, type 1 subbase, to the correct levels, and a very large vibrating roller to compact etc, everything seems to have been done correctly and the company have fantastic reviews/long term clients, but for some reason ours is having these slight dipping issues.
Any advice on the above?
Thank you in advance.
Are you a tradesperson and able to answer this question?
hi regarding you query,
we have had this problem in the past with the newly laid block paving,
but it does depend what is underneath the sub-base 7inchs of type1 is perfect to use but if its clay or soil then you would have a problem due to the sink-age being a heavy object is in the one position constantly witch is allowing it to do so, my advice to you is new sub-base with geo-textile membrane then a pre-mix cement screeded then lay your block paving, pillar or wall most probably their was not enough cement in the mix for a big wall the ratio usual is 1;3 or 1;4 varying thats a brief description of a job in bromley roughly about 3 years ago hope that helps
regards
Landscape PavingLTD
If you have a clay soil and they did not put a geotextile membrane under the base materials that could be one of the problems.
Recommended excavation for domestic drives is as follows 230mm dig out, Geotextile membrane laid over sub soil, 150mm of type 1 base laid in 2 layers with each layer being compacted, 30mm of sharp sand which should be screeded then the blocks laid followed by brushing in kiln dry sand and wacked with wacker plate, Sand brush off and site left neat and tidy.
As to the wall almost certainly not enough cement in the mix. They may also of failed to use any plasticiser which also helps.
Answered7 September 2014
4
Anonymous user
sounds to me like there is to much depth of sand under the block, the usual is 200mm type 1 and max 50mm sand, if the sand is any deeper it will sink as sure as ducks swim
Answered6 November 2014
4
Anonymous user
It's because the base they put down isnt good enough you would need to lift the whole drive up and put a new base down compact it with a machine then the sand compact with machine then blocks you should never get a problem
Answered3 April 2018
4
Anonymous user
To much sand will cause dips less sand more type 1. A pro would know if it needs more type 1 or not
Most of the time sinkage in Block Paving is caused from the sub base not having the correct compaction and/or the correct depth which ideally needs to be no less than 150mm. Or as others have already stated the depth of the sand may be to thick and not compacted properly.
Answered15 November 2017
3
Anonymous user
There are various reasons to why you have the problems your experiencing.
1. Inadequate sub-base material or the depth it’s been laid to and how it has been compacted, No less than (150mm of certificated Type1 MOT or primary scalping should be considered, compacted in two layers at(75mm). Any recycled material or material that contains organic matter I.e (soil fines) will only cause the sub-base to fail prematurely and is not acceptable.
2.To much sharp sand as a laying course (new British standards state (30mm). Any more than (50mm) and not compacted Properly will only allow for additional movement of paving.
3. Paving hasn’t been compacted enough/correctly after being laid. In that case it’s probably because the paving wasn’t even laid to correct heights beforehand.
All traditional block paved driveways should have a geo-textile membrane installed between sub grade and sub base not mater what the sub base comprises of.
If your on heavy clay and you have a membrane or not It’s irrelevant as it’s not possible to stop the ground from heaving. A Geogrid ground stabiliser and or a reinforced concrete sub base with expansion joints would be the only option to avoid problems with clay sub grade.When clay heaves the ground will expand when saturated with water Amd the ground below will expand.the paving will be affected to some degree not matter what Unless installed correctly.It’s most likely to be down to poor installation.
Block paved driveways are not a rigid construction so yes there is always the element that the paving may move slightly depending on the pressure it’s been put through. But unlikely unless your vehicles weight more than 3.5ton.
Alarm bells should start ringing Given it’s only been 3 months and your experiencing these problems
It’s absolutely ludicrous to say you need to take your driveway up and start again without a inspection of the sub base and laying course. A few trial holes will determine how the driveway was constructed. Then you’ll most certainly have an answer.
What is also worrying is the condition of the blocks that were laid.
Inferior paving most likely equals inferior materials elsewhere.
If you’ve been provided with a guarantee this should be upheld.
Not seeing how driveway constructed,
Am inclined to think contractor used hardcore under sub-base .
Over time water passing through a permeable driveway will remove fines of type1 roadstone, therefore creating pockets ,and therefore driveway sinking.!!
As with all driveway installation the base is 90% of work and should be compacted in layers .
Using too much sharpsand will also overtime ,do the same.
3 months is certainly too soon to be experiencing such problems !!
