The Brew Cabin

Posted: **Tue Apr 26, 2011 1:00 pm**

I have just laid a silver grey granite patio and it appears the sand cement bedding mortar has been drawn through the stone and has contaminated the surface of the granite. The result is a rather unattractive and patchy finish.

The supplier were not a lot of help, they advised that I should have laid it on white cement (pity they didn't provide this advice at the time of purchase).

Has anybody else come across this and it there a cure for the problem?

Thanks in advance.

Posted: **Tue Apr 26, 2011 3:18 pm**

Are you sure it's the cement and not just damp patches, did you prime the underside with a sbr slurry? Photo's please.

Posted: **Tue Apr 26, 2011 6:43 pm**

Hi, thanks for the reply. From the response of the supplier I would say this is a common problem and therefore assume its not damp patches.

I didn't use a primer, would this help. I am new to this site and cannot work out how to upload photos - can you advise how I do this.

kind regards

Posted: **Tue Apr 26, 2011 7:13 pm**

white cement should have been used in the mortor mix,

Posted: **Tue Apr 26, 2011 7:16 pm**

I didn't use white cement, is there anything I can do now to improve it, without taking it up and starting again?

Posted: **Tue Apr 26, 2011 8:02 pm**

try contacting the manufacturers to see if they have a solution, by using ordinary cement you may well have stained the granite beyond repair

Posted: **Tue Apr 26, 2011 9:47 pm**

The supplier (manufacturer) were unhelpful. They don't have technical staff, just sales people. They suggested I contact this site for help.

regards

Posted: **Wed Apr 27, 2011 8:14 am**

Hi Shaz

We recently laid silver grey granite paving at our display yard and had no problems with any mortar residue leaching through, so I am a bit surprised that you have faced this problem.

Would be good to see some photos so we can give you the best advice. email them to: steven@londonstone.com and I will upload them onto the site.

In my experience there is no need to use white cement on a material as hard as granite. We supply lots of sawn sandstone which is much softer than granite and we never reccomend that our clients use white cement, so i dont see any reason why you should use it with rock hard granite.

Once we see the photos we should be able to give an explanation and solution, but I would not worry too much as the effects of mortar leaching are usually temporary.

Posted: **Wed Apr 27, 2011 8:25 am**

Group: Moderator
Posts: 8318
Joined: July 2004
Posted: 01 July 2007,18:54 QUOTE
The Brew Cabin uses some fairly basic coding to enable members to upload their photies. This is how to do it....

You will need:~

The photies stored somewhere on the web
The url (address) for where the photies are stored
About five minutes free time
A little bit of patience

Pleasae don't upload effing huge photies that take three days to download - you'll only annoy your potential readers. The Brew Cabin is set up to have a width of 720 pixels, so PLEASE PLEASE PLEASE keep your photies to a maximum width of 600 pixels. If you really want to impress people with ginormous photies, just provide a simple link rather than distort the carefully designed layout of the Brew Cabin.

So: you have uploaded your photies to your own webspace or a website somewhere out there in cyberspace. To make them appear, as if by magic, in the Brew Cabin, you need to include a little bit of code in your message. Here's the code...

Code Sample
[img]http://www.Name OfYourWebspace.com/photie01.jpg[/img]

You MUST use the square brackets around the IMG tag, and you must use a closing tag (ie: /IMG within square brackets. The square brackets are the two keys to the right of the P key on most keyboards.

You need the FULL url, so that means the http bit, the www bit, all and any backslashes or forward slashes and the full name of the photie itself. The easiest way to do this is usually to navigate to the photie using your browser, whereupon the FULL url should appear in the browser's address bar. You can copy and paste it from there - easy!

Note: due to the nefarious activities of certain one-handed surfers and eejits peddling drugs, the code does not allow photies from dynamically created sites to be uploaded. This prevents the Brew Cabin becoming some sort of animated billboard for all the crap you don't want. It also means that SOME photo-sharing sites are "out of bounds" and will not work with the above code.

If all else fails, you can always staple your photies to a ten pound note and email them to me at the address given on the website and I'll upload them on your behalf.
There you go shaz courtesy of T Mc the governer.

Posted: **Wed Apr 27, 2011 9:51 pm**

These are the photos of the granite

I dont really see any major issue with it. It's just a bit of efforecence/leaching which will be gone within a couple of months at most

Steve

Posted: **Wed Apr 27, 2011 9:56 pm**

I cannot see any issues with it just looks a little damp IMHO
LLL

Posted: **Thu Apr 28, 2011 7:47 am**

Thanks for your comments. I will wait and see what happens. If things don't get better I'll contact you again. For now you have eased my concerns a little. Thanks again.

Posted: **Thu Apr 28, 2011 11:27 am**

Staining and contamination of pale-hued flags emanating from the bedding and/or jointing is a known and growing problem, so much so that several suppliers/manufacturers are now, somewhat sheepishly, adding yet more small print to their brochures to get them out of trouble.

The current thinking is that by using a silver sand and a white cement, any stain or contamination can be avoided. I'm not 100% convinced as I've seen some discolouration occur with Indian sandstone (Fossil Mint) even when laid using this method. However, it has to be said that there does seem to be less risk of stain/discolouring when this much more expensive method is used.

The science behind it is that silver sand has very little or no iron oxides (rust particles) and/or clay content which can be transferred from the bedding/jointing to the flag surface in more permeable materials, and that white cement lacks the grey-ish calcium compounds that are also implicated in staining.

The problem is that silver sand is often 2 or 3 times the cost of grit sand, and white cement is around 11 quid per 25kg bag, all of which means the cost of the bedding is often tripled, making installation more expensive and the customer much more likely to go with the cowboys who will use a bit of any old sand they can find and the cheapest OPC.

I have a page in production that explains all this, but with everything that has happened this year, it is a good way from being finished. If anyone is doing a silver-with-white patio job and can get me photies or let me come to take my own, it would be an enormous help.

Posted: **Fri Apr 29, 2011 12:00 pm**

I understand the logic behind using silver sand and white cement but I dont think it is necessary.

We always tell our customers before they order stone to expect a bit of leaching/efforecense (is that the correct spelling? I seem to spell it a different way everytime?

). In my experience it never lasts more than a couple of months and we have never had clients come back to us months-years after a sale and complain about leaching/efforecense.

The big problem comes when suppliers dont make their customers aware of the problem and the first thing the cusstomer sees are lots of dirty looking stains all over the new patio.

The Brew Cabin

Granite stained - Granite stained by bedding mortar