Block paving

Haych

I’m hoping to have my driveway and garden path repaved in the next few months and am currently obtaining quotes from tradespeople, when they bother to turn up. 

Initially I was hoping to have pattern impressed concrete but I cant find anyone locally who does it (I prefer to use local people when I can) and the cost I’ve had from others is prohibitive. 

The most popular surface seems to be bonded resin but again quotes are prohibitively expensive. Block paving, however, seems to be much more reasonable. 

So that was a load of guff for what is essentially quite a simple question. One guy who quoted said he lays block on top of cement dust instead of the usual sharp sand. He claims it’s more durable although I’ve never heard of this before. 

Is this true or is it bollocks that should be ringing alarm bells?

To be fair to him he showed me a large portfolio of work he’d done and online reviews don’t seem to be anything but positive. 

ESBlonde

My thoughts as someone that once layed a small block patio 20 years ago. ;-)

One of the advantages of block on sand is that some rainwater can be absorbed through it rather than run off and add to the street drain problem. I wonder if cement dust would in time solidify and prevent absorbtion. Also spashed cement can cause some staining of the block if not done properly. This may give better long term stability and reduce his guarantee risk, does it do it for you. You have seen his photos of previous work though.

boogieman

I call bullshit, cement dust wouldn’t have any strength on its own. Sharp sand is the normal thing. Whatever happens, it needs to be dug out to a decent level and have a sub base of compacted hoggin laid first. A lot of workmen leave this out and just put down a layer of sand, that’s why the blocks sink after a few years.  

Fretwired

My neighbour recently had his drive done with block paving by a local firm with an excellent reputation. They dug the foundations like they were building a motorway. The bottom layer was a base stone material of some sort that was compacted using a large machine. Then a layer of concrete-like material that was smoothed out followed by some sand and the bricks. His previous block paved drive way had sunk and when it was dug up the owner said they hadn't built proper foundations. He has a nice pattern in his bricks .. can post a pic if you're interested.

The same firm built me a new drive and laid paving (not block paving though).

octatonic

Sounds like someone has a load of cement dust to get rid of.

Budgie

Cement dust? As in portland cement? I think I would clarify with him what he means.

I've done loads of block paving and it's a simple case of excavating to accommodate a minimum of 150mm MOT type 1 sub-base (for driveways (100mm for anything else)), 50mm of compacted bedding (sharp sand) and whatever the depth of the paver used. The edges are laid onto concrete and haunched to anchor. The joints are then filled with kiln-dried sand.

zepp76

I used to be a block pavers labourer and have never heard of using cement dust, you just need a layer of scalpings compressed with the whacker, a layer of sand levelled then lay the blocks, brush kiln dried sand into the blocks gaps then go over that with the whacker and brush more kiln dried sand into any remaining gaps and it's job done.

Dominic

" cement dust "........is type 1 aggregate
I have a friend who has a national pattern imprinted concrete business
pm me if you want to be put in contact

Haych

Hmm, so seems like a bit of an oddity then. My logical mind seems to wonder, if everybody else uses sharp sand, why is this guy using cement dust?

But, like I say he has rave reviews - although I guess these could be spoofed, and a large portfolio of work to show, at all stages of completion. 

Some pictures he showed me clearly showed the cement dust being used so looks like he’s been doing it this way for a while. 

strtdv

A lot of people seem to be using quarry dust. It does somewhat bind to itself but isn't impermeable.
You're still going to need the MOT-1 sub-base,
I put my paving down on MOT-1 with quarry dust and a sandy concrete mix where needed, then sand for the fine gaps between slabs (I had them essentially touching).

I'd say it's six of one and two threes of the other tbh.

Budgie

Dominic said:

" cement dust "........is type 1 aggregate

It definitely isn't... MOT Type 1 is crushed limestone which is crushed from about 40mm down to dust, which binds it when compacted. It doesn't contain cement.

Dominic

No.........I know, but because it's grey I thought they were confusing it..........I also thought they might be confusing crushed granite which can look like cement dust.

Rocker

I fear that you will have weeds growing between the blocks sooner than later. And there is bound to be some unevenness especially if you drive your car over it. Tarmac with a border of the same bricks your house is built with. Don’t make work for yourself. 

Haych

Rocker said:

I fear that you will have weeds growing between the blocks sooner than later. And there is bound to be some unevenness especially if you drive your car over it. Tarmac with a border of the same bricks your house is built with. Don’t make work for yourself. 

It can’t be worse than what I have now, which is a mix of tarmac, concrete and flagstones, many of which are broken and uneven. 

Block paving has its issues I’ll admit but many other surfaces do too. The tarmac that’s currently there has weeds growing through it. The only surfaces which are less likely to suffer are bonded resin and concrete, both of which are much more expensive. 

ToneControl

Block paving is very expensive, and always seems to grow weeds and subside
Concrete, and pattern-imprinted concrete often need digging up when some underground services need replacing

There's a reason we have tarmac on the roads, it's hard wearing and easier to fix

I suspect the cheapest option would be to lay a reasonably solid foundation, then cover (possibly with membrane) and grit/gravel, as used by rural car parks everywhere

My Mrs keeps wanting to brush cement into the joins on our block paving
I've gone off block paving

Iamnobody

I don’t know if it’s cheaper but round here I see a lot of people going for a single or double block edging all round and a deeper block apron at the front - maybe 10 rows and then tarmac for the rest.

I need to do our driveway next year (or more accurately pay someone else to do it) so this thread interests me. 

I have no idea how much it should cost though.

hywelg

Whatever you lay it is now compulsory for it to be permeable. 

Foster

strtdv said:

A lot of people seem to be using quarry dust. It does somewhat bind to itself but isn't impermeable.
You're still going to need the MOT-1 sub-base,
I put my paving down on MOT-1 with quarry dust and a sandy concrete mix where needed, then sand for the fine gaps between slabs (I had them essentially touching).

I'd say it's six of one and two threes of the other tbh.

MOT (Ministry of Transport in case you were wondering) is a rather old term (as is DOT, Department of Transport), T1SB is pretty much the norm. 

Chances are that you'll probably get Crusher Run which is a cheap by-product of the crushing/sieving process, it's essentially any old shit that falls off the belt. It *can* be suitable for what you want but it's a complete gamble as to what the grading result is, this is why it's cheaper than T1SB.

Generally speaking for a random bloke off the street you might pay £20 per ton for T1SB, usually £8 for a regular client with haggling skills. The material that it's composed of is the most important factor - shit limestone can easily be crushed to smithereens whereas good stuff is pretty solid, depends on the quarry it's from. If in doubt you can ask for the specification sheet and look at the BSEN grading result and the LA result. Same goes for concrete, most reputable firms will have regular tests on any concrete mixed up.


If you have a preferred material type just ring up a local quarry, they don't turn business away. Most will let you collect if you have a trailer and a tarp (essential if it's a limestone quarry, you'll most likely be turned away if you don't have a tarp). Builder's merchants sell the same stuff but they'll have bought it in from the local quarry anyway.

ToneControl

hywelg said:

Whatever you lay it is now compulsory for it to be permeable. 

not according to this
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/7728/pavingfrontgardens.pdf

is says it must drain to somewhere permeable, or otherwise you need planning permission 

spark240

After having blocks for 20 years I wouldn’t do it again....it’s a permanent maintenance job, cleaning, sanding, weeding etc,

Though we didn’t have the best blocks it seems, our neighbours had a slightly more gloss finish block which seems to have lasted much better.

im looking to do a driveway now, and would go with the block edges and tarmac or resin.

my mate has the printed concrete which looks good, but the slightest frost and it’s deadly.