Paving grout cracking from new

[crackennz]

Hi all,

Just wondering if anyone has had paving done where the grout cracks 4-5 weeks after being layed?

The contractor said there would be an element of cracking but this is literally covering 90% of the 50sqm area.

It is around a fibreglass pool area so understand that due to the wet rainy winter the ground will dry out and could lead to movement however it doesn't seem like enough time to me for that to happen.

They all run linearly along the side of the pavers.

Any thoughts or experience?

Cheers
Phil

[jimO]

username irony

[John the builder]

Hi all,

Just wondering if anyone has had paving done where the grout cracks 4-5 weeks after being layed?

The contractor said there would be an element of cracking but this is literally covering 90% of the 50sqm area.

It is around a fibreglass pool area so understand that due to the wet rainy winter the ground will dry out and could lead to movement however it doesn't seem like enough time to me for that to happen.

They all run linearly along the side of the pavers.

Any thoughts or experience?

Cheers
Phil

more information please....
do you mean a concrete pad? if so Ring Firth or the concrete supplier, as they have experts who will assess?

[erinak]

?????
I don't get it?

[crackennz]

Hi John,
Sorry I’ll be more specific...
The pavers are 600mm x 600mm concrete (or whatever they are made from but assume it’s poured concrete with whatever else paving stone makers add.
I also had coping pavers made which are 300 x 400.
I have a fibreglass pool and as is standard with fibreglass pools the lip runs horizontal with the ground around the entire pool to form the look of coping.
When the pavers were installed there was a bond beam (poured concrete) added underneath the fibreglass lip/coping so the smaller 300 x 400 coping pavers/tiles could be glued on top of the fibreglass lip to form a paved coping for the pool.
Around the remainder of the pool area the 600 x 600 pavers were settled in on a compacted bed of whatever they used.
After that they grouted between the pavers and after a few weeks cracks appeared running linearly along the side of the pavers.
By that I mean the cracks run the whole length of whatever paver I am looking at on one side of the grout/paver and the other side of the grout line stays attached to the opposing paver. There aren’t really any cracks that run sideways across the grout except where the pavers all meet at their corner points.

I tried to upload a photo with my first post but for some reason this website and my computer don’t agree.

[John the builder]

Hi John,
Sorry I’ll be more specific...
The pavers are 600mm x 600mm concrete (or whatever they are made from but assume it’s poured concrete with whatever else paving stone makers add.
I also had coping pavers made which are 300 x 400.
I have a fibreglass pool and as is standard with fibreglass pools the lip runs horizontal with the ground around the entire pool to form the look of coping.
When the pavers were installed there was a bond beam (poured concrete) added underneath the fibreglass lip/coping so the smaller 300 x 400 coping pavers/tiles could be glued on top of the fibreglass lip to form a paved coping for the pool.
Around the remainder of the pool area the 600 x 600 pavers were settled in on a compacted bed of whatever they used.
After that they grouted between the pavers and after a few weeks cracks appeared running linearly along the side of the pavers.
By that I mean the cracks run the whole length of whatever paver I am looking at on one side of the grout/paver and the other side of the grout line stays attached to the opposing paver. There aren’t really any cracks that run sideways across the grout except where the pavers all meet at their corner points.

I tried to upload a photo with my first post but for some reason this website and my computer don’t agree.

pavers shouldnt be grouted as they are meant to move independently. I am more surprised that they havent all cracked the same. By end of summer they will have I expect. If they were laid on a concrete pad and glued then that might have worked?

or a very flexible grout?

Talk to the paving supplier?

[crackennz]

Well they kind of have all cracked the same...linearly and fully along one edge of the paving stone....if you picture 2 pavers together with the grout or mortar (whatever you want to call it) line in between, then picture a crack running fully along one edge of one paver while the grout/mortar is still attached to the opposing paver.
I would assume flexible grout/mortar should have been used if it exists but it would appear not.
To be honest, every quote I got before going ahead with it mentioned grouting between pavers and I’ve never seen pool coping without grout/mortar in between the coping tiles/pavers.
Actually nor any paving without grout unless it’s the permeable type or has a grass or shingle feature layer in between.

[Bob Kane]

Around the remainder of the pool area the 600 x 600 pavers were settled in on a compacted bed of whatever they used.

There's your problem.
The compacted bed is flexible and moves.
Grout would never work over a flexible base.
If you had poured concrete over the compacted base then it would be rigid enough for grout.

[crackennz]

Hi Bob,

So I found out what method was used and it was a compact bed of base material then a 4 to 1 slurry mixture of sand to cement approx 20mm thick...this is what the pavers were bedded into/onto so surely that should rule out the movement?
The joint filling mortar was a 3 to 1 silica sand cement mix - well that's what the paving manufacturer recommends.
I get it that grout does crack and to be honest I wouldn't have a clue how long it takes ground to dry out and for it to shrink and move but it just seems to me to much and too soon for both cracking and ground movement.

[Bob Kane]

If it's cracking within 4-5 weeks then the work isn't fit for purpose - not appropriate for the conditions.
If the contractor knows his stuff and backs his work then he'll repair it so that it won't happen again.
In which case let him repair it.
Doing the rework for free might make him take more care.
If he doesn't know what he's doing (as I suspect in this case) then he'll argue with you and won't offer to fix it for free.
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[John the builder]

If it's cracking within 4-5 weeks then the work isn't fit for purpose - not appropriate for the conditions.

that seems harsh?
it is still fit for purpose despite the cracks which are likely hairline in nature and inherent in the design. This is a minor blemish that doesnt affect use?

who was the designer? who chose paving and who decided grout jpints?

[crackennz]

I chose the pavers from a family owned business which has been operating for many years.
They recommended the paver who pretty much only installs their product..
I’m off to see them this morning to get their opinion....
Unfortunately on at least one piece of grout in the coping I could (if i tried) wiggle a piece of grout free....I can feel it’s loose.

[John the builder]

I chose the pavers from a family owned business which has been operating for many years.
They recommended the paver who pretty much only installs their product..
I’m off to see them this morning to get their opinion....
Unfortunately on at least one piece of grout in the coping I could (if i tried) wiggle a piece of grout free....I can feel it’s loose.

I have sympathy for the installer

Perhaps your expectations are unrealistic. (the loose grout accepted)

Love to here what the supplier says. Their opinion should settle the matter?

[crackennz]

Yes the installer was a good guy and was there grafting with his labourers...

Personally I don’t think my expectations are unrealistic....90 - 95% cracking seems excessive to me.
I have looked at many paved areas in my time around pools and don’t recall an abundance of grout cracks...certainly not along the side of every coping paver.

[John the builder]

you havent been looking at apple for apples. Most of those pools have tiles on concrete slab.

why did you even grout between pavers they are intended to be close butted.

Your expectation that grout will not crack is unrealistic.

what did the paver supplier say?