Block paving - Frezzing weather

[kenweb1]

Hi everyone. can anyone help. down to the weather (frezzing cold) my block paving has started to lift approx 25mm i think its down to ice in the sand under the blocks is this normail if not how can i stop this happening as it did it last yr. cheers RGS Kenny.
MERRY XMAS TO ALL .

[lutonlagerlout]

is it existing block paving ken or stuff you just laid?
either way it shouldn't be lifting 25 mm under any circumstances
LLL ???

[kenweb1]

Hi thanks for your reply its been layed 2 yrs and it lifting where the gates are but not the edging blocks approx 3rd row layed from the start.

[Tony McC]

25mm is a lot of heave for anywhere in Britain or Ireland. We don't normally get enough of a frost for that sort of damage.

If the edge courses are staying put, that suggests it's something directly beneath the affected area: a burst pipe, perhaps?

Even if the edge courses were, as they should be, laid on concrete, while the body blocks are laid on sand, there's no way 25-50mm of sand can expand 25mm in a frost. If the sub-base has heaved, then why hasn't it heaved beneath the edge courses?

The short answer to your question regarding how to stop it happening is that you can't. Like Knut couldn't stop the tide, you can't stop the frost. Those crazy North Americans have heated driveways, similar in principle to underfloor heating, in order to keep their main access free of light snow and ice during the winter but the cost is rarely, if ever justified on this side of the water because we don't tend to get week after week of sub-zero temperatures (he says, after two winters of exactly that!)

[kenweb1]

cheers. i guess my drives a bit diffrent then ..there are no pipes under it as i did the job myself and took all the tips and what to do how to doit from this site so i know its done right.
__ i will wait till weather warms up and lift a few blocks out to see whats going on thanks fellas

[colordrives]

Have seen this recently did you by any chance use "Dust" as the screed layer?

[kenweb1]

no i put sand but now the snow and ice has gone its seems to have settled again i now think is down to the way i have
put the tracks for the electric gates im going to put 10mm round bar down and remove the tracks that way nothings in contact with the blocks i will post how things work out. i will do it b4 the next snow fall:)

[g.stewart]

hi, anyone know a good method of thawing out type one so we can proceed with installing block paving.I was thinking of hiring one of those space heaters "the rocket shaped ones"
as we have had 2 weeks of snow(no work!).Now the snow has melted the ground is frozen and i know the job should be a non starter,But i was thinking its to stay cold and would this space heater thaw a 30sqm area enough to allow compaction and laying of blocks and leaving final compaction till weather improves, maybe in january!
ANY IDEAS!
gil from glasgow

[Tony McC]

I've seen this done before, on a retail unit in Chester where the car park had to be opened at the same time as the main store, so a marquee was built over the parking area (around 150-180m²) and an array of space heaters roasted the site for 3 days before the paving gang went in to grade sub-base, compact, lay sand and paving, joint and compact.

Not sure how much it all cost. The contractor told me the shop owners had agreed to foot the additional costs, but I bet it wasn't cheap.

I was passing the same site about 4 months later, mid-Spring, and the whole area was noticeably uneven. Whether this was due to the extraordinary working methods or general incompetence by the contractor, I can't be sure. I know that particular contractor is no longer trading.

[rab1]

I`ll get someone to post the picture but noticed tonight that on my drive there is a distinct raised line, Its where the original drive ended and when monoblocked included the 4m2 grassed area at the side of the original drive.