The Brew Cabin

Posted: **Mon Dec 14, 2015 8:45 pm**

Hi To You All. I am new to this forum and would be gland for some advice. I also have some ideas and would like to run it pass the experts.
I intend to lay Bradstone Granite pavers but I am a little apprehensive about some of the damp patch issues. I intend to make a sub base of 100mm thick (30mm chippings to dust) over an area of approx 100 sq metres, The pavers to be laid on a wetish full bed of mortar ( grit sand & white cement 5:1 mix) with plastizer added. A bridging bond applied to the underside of the paver,(SBR diluted with water 1:1 and white cement added to form a brush on paste)
My question is:- if I coated the pavers with a impregnator on the top surface and edges prior to applying bridging bond would this minimise the possibility of getting damp patches coming though the paver? It would be a while before I got I time to grout these paviers therfore moisture could get in from the edges.
In the past I laid a natural stone floor in a kitchen and applied a impregnator to the stone before grouting,This made it easier to clean off excess grout.

Posted: **Mon Dec 14, 2015 9:25 pm**

If it's silver granite unwrap them and give them a good soaking down the night before (probably be done for you at the moment). I always lay them on a semi dry mix with sbr added not plasticiser.

Silver sand with white cement is said to be best for laying silver granite.

Posted: **Mon Dec 14, 2015 9:45 pm**

Hi Dempsey of Liverpool, Thanks for your very quick reply. The pavers are silver grey. I take it you don't use a bridging bond and add sbr in mortar mix. What is your success rate using your method in preventing damp patches? Have you tried applying an impregnator to the pavers before laying them? If not, what are your thoughts on this?

Posted: **Mon Dec 14, 2015 11:00 pm**

Yes I still coat the backs with sbr/cement slurry. I've had no issues to date. Never used sealents or impregnators on natural stone it seems to of done ok without it for the last few thousand years

Posted: **Tue Dec 15, 2015 8:42 am**

That of course is true â€“ but on the other hand for the majority of those thousands of years there hasnâ€™t been BBQâ€™s with oil, hamburgers being dropped on them. Or beer or Coke or milkshakes for that matter!
I always protect the surface of the paving I lay â€“ having said that, this is the wrong tone of the year, wait till Spring
Gary

Posted: **Tue Dec 15, 2015 3:37 pm**

Most granites are fairly impermeable so most sealents or impregnators will just sit on top. I personally wouldn't seal granite. But if you must I'd let it weather for a year, clean off the oil, drinks and burgers

Give it a few dry days (spring/summer) then apply your sealent/impregnator

Someone will be along with more knowledge of sealing than me

Posted: **Tue Dec 15, 2015 4:59 pm**

Hi Dempsey of Liverpool, Thanks for your reply. You say you would put SBR in the mortar mix. Can you tell me how much you would put in a 5 to one mix. As far as the impregnater is concerned, it was my thought on how to prevent moisture being sucked into the edges of the paver as it wont have been grouted until later. One other thing you mentioned was to use Silver sand. Is this like sharp sand? I have been told Building sand is not suitable, a course grain sand is preferred.

Posted: **Tue Dec 15, 2015 5:07 pm**

Hi GGG, Thanks for your reply to my queries.To use an impregnater on the pavers before SBR bridge bond is applied was my idea to
help & stop any ingress of moisture into the edges of the paver and possibly causing stains. I dont know if it will work. Any reasonable preventative measures for unsightly patches I think would be worth while. Thats why I am asking the experts

Posted: **Tue Dec 15, 2015 6:09 pm**

Silver sand is a silica sand with low iron content that reduces staining. It's like a clean, fine sharp sand.

Never use building sand.

The Brew Cabin

Granite pavers laying advice - Help in preventing damp patches