Hollow sound under patio slabs - Please can you advise

[cpjpage]

We had a patio laid professionally in the spring 2012. It is in Indian sandstone and looks beautiful. We were told not to walk on it for two days, which we didn't.

When we went on it we found about 7 slabs loose and a further 12 that sounded hollow under foot and when tapped them.

We contacted him immediatly asking him to fix this. He came round that day without telling us, and when we were out and proceeded to fix the slabs. Even though we asked him to come and see us and we would point them out.

He fixed the loose slabs by repointing but he was sloppy with the mortar and stained those slabs. We still have hollow sounding slabs and now have found some more loose ones.


We wrote to him again:
"Thank you for working on the patio. However, we are sorry to say this, but we are still dissatisfied. Each slab we marked, still feels and sounds hollow or has hollow gaps underneath.Whereas the majority feel solid under foot. We would like these hollow slabs to be fixed to the same standard as the others.

Also we would like any staining on slabs made by pointing to be cleaned or the slab replaced.


We would like this work done while we are away on honeymoon between 6 - 20 August 2012. As doing it before is going to be too disruptive in preparation to our wedding on the 4th August.
Before you left on Tuesday you did say that if we were still unhappy that you would fix it, you continued to say, this fixing would involve taking up faulty slabs and relaying in fresh cement then re pointed to match the rest."



His reply was:
"sorry for the delayed reply, we just got back from holiday this morning, so I'm getting through my emails now. Sorry the re-pointing didn't do the job. I will be happy to re-set those that are still iffy and re-point as necessary, and clean up etc. I have written it on my calendar to get it sorted whilst you are away.
Hope all goes well with the wedding.
Best wishes..."


We though great and replied saying so. Ours neighbours said they would keep an eye on our house, while away.

We returned from honeymoon and went straight to the patio. He had fixed the loose slabs, attempted to clean the staining however still looked messy, and we still had a hollow sound under the slabs. We felt very disapointed.

He hadn't left any notes as he promsed and as he had used the outside socket it had tripped the fuse in the garage.

We left it a few days and deceided to write and ask how he got on. We heard nothing for about a week. So we emailed again, asking the same thing.

This is his reply:
"I Went over the whole patio and lifted the slabs I thought were a problem. Once I had them up and could investigate, I could see that the 'hollow' sound must just be coming from the few voids in the concrete that occur under most of the slabs. These voids weren't big enough to pose a threat to the patios stability, and the concrete has gone off very hard so all the slabs are well supported. As I had them up, I ground some of the concrete away and re laid them. I then re pointed and cleaned up afterwards. In all I was round yours nearly two days getting it done.

I am confident now that the slabs are well laid, and well supported. I can assure you that if any remain that sound hollow, there is no problem with them and it is just a result of the laying process and how the concrete had dried." {end}

We still have a few slabs that are loose again.

Please can someone advise me if he is telling us the truth and should we have him back to fix the hollow slabs. This is getting frustrating and we feel very let down by his work. We were recommended him and we judged that his work would be good. He was our second expense quote for the job.

Many thanks for reading and replies are very welcome

Chris

[local patios and driveway]

Although in my own opinion from your side of the story it does sound like the method used to lay the stone wasnt correct, im impressed that he is clearly trying to correct any issues, thats a good sign, the good guys go that far and rightly so. The fact that he probably tripped the socket from using a grinder is also a good indication but also coukd mean he couldnt grind everything at some point... I think you need a face to face meeting and look at the job together share your concerns. I will admit ive had the odd hollow sounding slab but never had an issue with slabs lifting on any job apart from one early job in my career.

[lutonlagerlout]

^^
he doesnt sound like a bad sort
hollow flags doesnt always mean voids
it can be the stone delaminating
LLL