Stains on half of block paving

[jedi]

Hi all I`m new on here and I am looking for some advice on some block paving we have recently had laid.

1 half (the right hand side in the pictures) seems ok, some slight efflorescence thats all, but on the other side (the left hand side in the pics) they seem to have white specks every where? Is this cement? crushed sand? both or something else, The paving installer says its just efflorescence, but I really think not. Now its drying out a little it looks quite bad. any idea`s
The gold spots on the right hand side are just paint where I have marked broken blocks for them to replace.




??? ???

[jedi]

any one? Could it be an inferior pallet of bricks? I know the left side was laid 1st? I just can`t understand why its like this just on the left side, and theres a clean break between the good and the bad side? Its like Jackel and Hyde paving?:p

[Dave_L]

Blocks from a different batch - that's why any paving like that is best laid from 2/3 packs to avoid any 'different' areas.

I'm no paver but that's what I understand.

[jedi]

Hmmmmm? will this sort its self out in time? or will it always look like this, it just looks rubbish. is there anything I can do about it?

[Paul Miller]

I'm no paver either, but there appears to be a clear divinding line down the centre, and the those blocks on the left look considerably darker than the right. I wouldn't be happy with that either. I'm expecting to get effloresence on mine when it's done, but would expect it to go in a few months. I'm afraid that I can't offer any suggestions, but I hope you get it resolved satisfactorily.

[mickg]

the colour variation is caused by either a different batch during manufacture or the right hand side blocks have been stored in the manufacturers yard or a builders merchants yard for a longer than normal period in time and has faded slightly as you can see a distinct colour difference from pale on the right to very colourful on the left

what was the manufacturers name on the shrink wrap around the blocks when they were delivered ?

the paving installer has not taken blocks from 2 - 3 packs and mixed them together whilst laying the patio hence the reason why it looks like a patchwork quilt, the patio will fade slightly over a period in time due to the weather but you will always see this divide when the blocks are bone dry

the white specks without seeing a close up of the blocks could be kiln dried sand compressed on the face of the block due to the fact the blocks were wet when the vibrating plate was used to compact the patio, try using a stiff brush on the blocks to see if the marks disappear or a scraper lay flat on the block and just push forward and backwords lightly to see if the marks disappear.

if they don't disappear then it could be efflorescence, if you take a close up photo of the white marks it will give us more info as to what they might be

efflorescence is something that all the paving manufacturers can't stop happening and can happen on some batches and not on others and there is no defined reason why this is so, it does normally disappear after a few months but can return time after time when we have a warm spell and the paving dries out completly.

[jedi]

Hi Mickg, Thanks for you reply.

The blocks were Driveline 50, I presume manufactured by Marshalls?
Also the left hand side always seems wet, or a least always takes a lot longer to dry out, even though this side gets the sun the most, any ideas why this could be?

I`m pretty sure they did not mix the pallets of blocks either, as they were stacked on top of each other when they arrived.

The 1st 4 photos below are from the affected left hand side, the 5th last photo is a block from the good right hand side.

I hope these help.

Speckles on this block:


A milky sort of substance on this one, or is it cement?


More specles again:


Again a mily substance, effloresence maybe?


A good brick for the right hand side for comparison:

[mickg]

I thought it was a Marshall's block as you can see the marigold colour on some of the paving

photo1
these look like scuff marks where the blocks have been moved from the pallet into a wheel barrow and the blocks have been banged or rubbed together, normally these go when you have surplus kiln dried sand on the surface whilst using the vibrating plate to compact the blocks into place

either that or its dust or dirt what has not been washed off

photo2
looks like the dust from where they have been cutting the blocks and they have not washed it off, needs a hose pipe on a fine to medium spray and some using a stiff brush at the same time as the rain will not dislodge it

photo3
same as photo 1

photo4
this is efflorescence on the full block in the centre, the block just below looks like its the dust from cutting again, needs to be washed off using a hosepipe and stiff brush as the rain will not remove it

photo5
looks fine

[jedi]

Hi Mickg

These blocks have been scrubbed twice now with a stiff brush, and those speckles do not want to budge. These photos were taken sometime after the 1st wash and scrub, I have just done it again today, and it just looks the same.

You sure this is not cement stains, or as someone mentioned above, crushed in sand because the blocks were wet? They did use a lot of cement to do the edges near where the grass is, and also to the very left where a couple of new fence posts had to be put in.?

O and I just remembered this left had side, did`nt have much sand brushed into the joints when they left? they said they would have to come back to do it for some reason?

Do you think they already knew of this problem?

[lutonlagerlout]

jedi did they haunch the edges after they had laid the blocks?
this would explain possible cement splashes and is generally frowned upon as bad practise
also the shape of that curve and the darts and wedges cut into it are not good practise
its almost certainly a problem with not mixing from more than 1 pack,but the blocks are brindle so i would expect variations of colour, after all brindle is a multicoloured block and more pleasing to the eye than monotone blocks
see here for more info
cheers
LLL

[jedi]

Yep they did haunch the edges, they seem sturdy enough?

Shape of the curve and the darts and wedges not good practice? what do you mean by this should it have been do another way?

Do you think this is a good job? or are there problems with it looking at the pictures.

[lutonlagerlout]

ideally the edges should be laid before the main body of the paving
see here for details
also see here for info on cutting in
overall it looks ok,just silly things like mixing the blocks and the cutting in are not quite 100%
LLL

[mickg]

the white specks are
1: not crushed sand caused by running the vibrating plate over wet sand
2: not efflorescence

seeing as the blocks have been washed with water and scrubbed and its still there it could of been caused by a leaking wheel barrow or bucket when they have mixed the concrete for the haunching and it has dripped on the block paving

you need to get the installer back to rectify the problem plus he needs to add additional kiln dried sand to the patio anyway

[jedi]

Hi the installers are here today.

There is definatly specks of cement on some bricks which there changing now. and they say the other specs are "just dust" from where the wacker has crushed in the sand, they say this will weather/wash out? I could not remove these specs brushing with a stiff brush. Will these spec eventually weather out?

They say they will jet wash it if all esle fails????

Cannot update on any progress as the weather has turned bad, rain which make the blocking look nice, dreading it when it stops. Will have to wait and see. Not expecting any difference as not may blocks were changed, just the broken ones, so the colour difference I suspect will still be there.