Silver granite damp - What to do now?

Patio flagstones (slabs), concrete flags, stone flags including yorkstone and imported flagstones.
m4tthall
Posts: 11
Joined: Sun May 12, 2013 8:27 pm
Location: West Sussex

Post: # 89980Post m4tthall

mickg wrote:>>>>So what are my options, do I have any?

already given you my opinion above - sadly the only solution is to take it up and relay it or to live with it
If I got someone to relay it, in your opinion would that be in the same price ballpark as putting it down in the first place? Just trying to gauge how much it is likely to cost me.

Thanks

lutonlagerlout
Site Admin
Posts: 15184
Joined: Fri Aug 04, 2006 12:20 am
Location: bedfordshire

Post: # 89983Post lutonlagerlout

its going to cost more as they have to lift it and clean it
let it weather for a bit is my opinion and see what it looks like in 3 months
LLL
"what,you want paying today??"

YOUR TEXT GOES HERE

davieb1969
Posts: 2
Joined: Sun Jun 02, 2013 10:50 pm
Location: Northampton

Post: # 90359Post davieb1969

Hi, I've got the same issue, look like the same slabs actually. Our patio has been down for a year now, the supplier said it would disappear after a few months, but it hasn't changed. It's laid on a full bed of sand/cement mix, with a deep sub base. I don't agree with what someone has said about the framing being caused by slabs being butted together as the slabs at the edge have the same marks. I was told to use a gloss sealant as that might help, but I'm reluctant to spend £100 if it doesn't work. Any ideas?

Thanks

davieb1969
Posts: 2
Joined: Sun Jun 02, 2013 10:50 pm
Location: Northampton

Post: # 90362Post davieb1969

Matt, where did you buy these slabs from? Was it an online company starting with N and ending with stone?

cheers

m4tthall
Posts: 11
Joined: Sun May 12, 2013 8:27 pm
Location: West Sussex

Post: # 90364Post m4tthall

davieb1969 wrote:Matt, where did you buy these slabs from? Was it an online company starting with N and ending with stone?

cheers
Yes

London Stone Paving
Posts: 2199
Joined: Mon May 10, 2010 1:07 pm
Location: Surrey
Contact:

Post: # 90367Post London Stone Paving

In my experience the biggest cause of picture framing is when the mix is too wet and too much mix is used. The result is that when the slabs are knocked into place the excess mortar gets squeezed up through the pointing gaps and the moisture just sits there getting absorbed into the outside edges of the flags.

I'm a little bit puzzled as to this because its not the first time I have heard this issue with granite. Granite is a really hard stone so you would think it would not be susceptible to this kind of problem. In fairness to nustone the problem is not confined to them but the fact that their granite is only 20mm thick cant help

lana
Posts: 62
Joined: Thu Jun 06, 2013 2:12 pm
Location: Oxfordshire

Post: # 90467Post lana

Found this thread when surfed the net in search for the answer - just have my patio laid in the same silver granite and noticed few slabs stained in similar manner to Matt's, maybe slightly less, still too early to say, the patio is not finished yet.

On mine it was a very thick layer of mortar, not sure if it is spotted or even spread, as didn't see how they did it. I have also noted the mentioning of the building sand used as opposed to sharp sand somewhere in another thread, if it is relevant at all.

Having read this discussion, I'm begining to think there is no remedy to that apart from either re-laying for the extra cost or simply letting time and elements to weather this effect out slightly.

I have still questions, if someone can clarify this for me please:

providing the weather cooperates, and this moisture dries out slightly, not completely, I understand, but at least to the more acceptable level, and I'll seal the slabs with suitable sealant, would this help to see less of the staining in future?

my slabs are pointed, would this prevent or alternatively aid to the moisture to stay longer between slabs and therefore keep the edges look damp for the years to come?

I'm usually a timid customer, a thought of confronting my contractor with the fact they did it wrong freaks me out and I suspect if I do, they will manage to persuade me in the opposite anyway (always an easy job with a woman on her own ;-)) So I'm kind of half-resigned to the fact that my patio will not be perfect. But i still would like to know what to expect and what is better not to expect at all.
many thanks in advance for whoever will spare time share their wisdom.
~Lana~

London Stone Paving
Posts: 2199
Joined: Mon May 10, 2010 1:07 pm
Location: Surrey
Contact:

Post: # 90470Post London Stone Paving

Hi Lana

If the patio is not yet finished, is it possible for you to find out whether the granite has been laid upon a full bed or spots?

In answer to your questions

1. Its difficult to answer this question as the marks could be temporary or they could be in the early stages and may get worst. Time will tell. If the marks are going to be around for a while, i dont think that sealing would help to cover them up. Can you post a photo?

2. Depends on the nature of the marks. Are the marks "picture framing" or are they just random across the slabs. Again a picture would be helpful but I would say that the fact that the salbs are pointed will not make a difference to how quickly the marks will fade

You should not feel intimidated, as long as you are asking reasonable questions the contractor should be giving you the answers.

Steve

lutonlagerlout
Site Admin
Posts: 15184
Joined: Fri Aug 04, 2006 12:20 am
Location: bedfordshire

Post: # 90472Post lutonlagerlout

I went to see the "harvest sawn" patio we did the other week, and there was some evidence of picture framing

this was like 3 weeks on from installation

however i know its rock solid on a full bed
the mortar if anything was deeper than the flag thickness so this can only be the pointing mixture causing the framing

I have have never had framing on normal riven indian stone and my technique was exactly the same for these

the client is happy for weather and time to take its course

LLL
"what,you want paying today??"

YOUR TEXT GOES HERE

m4tthall
Posts: 11
Joined: Sun May 12, 2013 8:27 pm
Location: West Sussex

Post: # 90474Post m4tthall

9 months on mine isn't getting any better after initially improving. In fact it has looked worse over the last couple of days in the good weather when I would have expected it to have been better. I have pretty much given up all hope.

London Stone Paving
Posts: 2199
Joined: Mon May 10, 2010 1:07 pm
Location: Surrey
Contact:

Post: # 90481Post London Stone Paving

lutonlagerlout wrote:I went to see the "harvest sawn" patio we did the other week, and there was some evidence of picture framing

this was like 3 weeks on from installation

however i know its rock solid on a full bed
the mortar if anything was deeper than the flag thickness so this can only be the pointing mixture causing the framing

I have have never had framing on normal riven indian stone and my technique was exactly the same for these

the client is happy for weather and time to take its course

LLL
Tony
It will be a bit of grout residue. Should go on its own but if not very easy to shift with lithofin builders clean

lutonlagerlout
Site Admin
Posts: 15184
Joined: Fri Aug 04, 2006 12:20 am
Location: bedfordshire

Post: # 90487Post lutonlagerlout

this looks almost like efflorescence steve
there is no mortar on the face of the flags
but obviously the high cement content of the mortar may have helped this
I am 100 % sure of the installation and methodology so it can only be the gun mortar
weird i have never seen it on riven stone
dandy's are doing a deal on weather point ,I may give it a bash on the small patio we are doing now
LLL :)
"what,you want paying today??"

YOUR TEXT GOES HERE

lana
Posts: 62
Joined: Thu Jun 06, 2013 2:12 pm
Location: Oxfordshire

Post: # 90492Post lana

I had a closer look last night and it looks like it is full bedded, at least for the most of the slabs. I had also few slabs lifted off the step to be re-laid for another resons and can see the mortar residue is deffinitely not in spots, but spreaded more or less evenly. I will take picture tonight and post, just for my own peace of mind. I have noticed that after we had few sunny days, the part of the patio that is in full sun shows less stains (or perhaps with silver grey sparkling the stain are not so visible?) the area along the fence looks more "wet" with the random stained patterns. Am I panicking too soon and what is the reasonable time after laying I should wait before declare it has problem? the slabs were laid a week ago only.
many thanks for all you inputs, have been most helpful!
~Lana~

lana
Posts: 62
Joined: Thu Jun 06, 2013 2:12 pm
Location: Oxfordshire

Post: # 90494Post lana

oh, just re-read what lutonlagerlout said and now have even more questions:
actually, when I said my slabs are pointed, I "lied", as they WILL be pointed in the next couple of days, for now they just have gaps between then to be filled, as per contractor, with the polymeric sand or similar. Now, this makes me think that the reason for my stains would be different and deffinitely not because of the pointing mixture. ok, that aside, now I have to ask: is there a "sure safe" pointing mixtures for granite slabs? I mean, if the pointing is still to be done, might as well requiest from contractor to use what I believe would prevent the possible unsighty effects from occuring afterwards.
I expect them to come to do it this weekend, so can still delay the process and ask for the appropriate material (unless their choice is already the one)
thanks in advance, guys!
~Lana~

lana
Posts: 62
Joined: Thu Jun 06, 2013 2:12 pm
Location: Oxfordshire

Post: # 90516Post lana

ok, this is plain spooky - just when I've found this forum and spoke about potential issues... this morning the slabs looked only slightly stained in places, noticable, but not too bad, we had a very dry and sunny day and when I came from work, I found what I feared most, as Steve said, they "may get worst" and sure enough - they did:
Image
Image

the symptoms are the same as Matt reported: nice sunny weather seems to made the staining more profound...
the "clean" slabs on the steps have been laid the last and only this morning the main patio area looked almost the same as the steps, random stains only slightly visible. in the evening it is all changed dramatically :-(
~Lana~

Post Reply