Granite paving advice - Granite paving recommendations

[Stanlyp]

Good Afternoon,

I have just taken delivery of around 110m sq. of Granite paving from a company called Nustone. The slabs are 600x900 - around 20-22mm thick.

They are for a new patio in our back garden.

I have a couple of questions that I need some help with.

Firstly I ordered a 100x100mm sample of the silver/grey granite and was happy with the colour/texture of the paving slab so then placed an order for the complete patio. The paving has arrived and I decided to take about a couple of the large slabs to have a look at them.

One side is what they called Flamed and the other is a smoother sawn finish. Rubbing my hand over the flamed surface its becomes very clear that this surface is very rough in texture which I couldn't really feel on a 100x100mm sample. We have 2 small children so I'm wondering if these slab can be laid saw surface up as i'm a little worried that children falling over on this will be like sand-paper on small legs/knees and cause serious damage.

My other option is to have them laid flamed surface up and then look at some form of sealer/protector that may make the surface smoother by sealing the paving? Can anyone recommend a sealer that does this?

If we can lay this sawn face up can anyone recommend a product/sealer that may add some for of seal/no-slip coating?

Also is it best to seal these before having them laid of wait a period of time before applying a sealer via roller/spray?

Thanks in advance

[lutonlagerlout]

the sawn side cannot be laid up as it doesnt meet the british standard for slip resistance,it will be like an ice rink when wet

the flamed side is fine if the flags are laid correctly ,but gets dirty very easily, this G603 granite is quite a porous stone and would be an idea to keep it dry and seal it before installation
dry treat and lithofin MN stainstop are 2 very good products but like all things come with a price tag

cheers LLL

[Tony McC]

You have to bear in mind that, generally speaking, we don't walk on paving on out highly-sensitive hands and fingertips. What might seem coarse or rough to the hand will actually be just about right for the feet, even unshod feet.

I know the stone to which you refer and the flamed side should always be laid face up. As LLL said, there is the Slip Resistance Value (SRV) to consider - we *need* some traction on stone otherwise you end up in A&E (if we still have them!) - but also consider that the flamed surface has specifically been selected and treated to be the 'wear face' on these flagstones. If you invert and lay upside down, you could invalidate any claim you might have for poor quality stone, cracks, fissures, failures, staining, etc. (not that any of these are more common with NuStone granite than anyone else's).

[Stanlyp]

Good afternoon,

The granite has been laid the correct way up.

The Contractor has been working for the last 8 days on our patio and has around 60M laid. The question just came up about sealing the Granite. The contractor is looking to use one of the brush-in products (EASYjoint) as we have gone for a 5-6mm joint between the stones. He has recommend that the patio has at least one seal coat applied before they grout the flags as without sealing the grout is likely to stain the flags.

I've got some prices for both drytreat and MN stainstop. The other product that looks to have done very well in the tests is Ad Sealing - HD sealer - http://www.advancedsealingsolutions.co.uk/Heavy-Duty-Sealer.html

How easy are these product to apply myself? I've been told that a microfibre mop is ideal.

I have been sent a sample and will apply the HD product this evening once it cools down a little.

Being that we ideally it needs a seal coat and the weather is warm how long should I leave it before applying one of these products? The MN StainStop and drytreat seem excellent products and being impregnator should allow the stone to still breath?

Thanks in advance

[Tony McC]

When properly applied, even the 1-part 'polymeric' jointing mortars such as that you mention should not stain. The key is to use plenty of water to prevent the stone absorbing surplus resin.

Sealing is easy. I normally use a lambswool (type) roller to ensure even coverage with no pooling.

How long to leave what? Leave applying the jointing? I'd normally joint then seal (see comments above), but if you want to do it the other way, then give the sealant at least 72 hours to get a decent degree of curing.

[Stanlyp]

Good Afternoon,

thank you for all the help and guidance so far. have cleaned all the cement marks and foot prints off with Builders clean and just waiting for a few nice hot sunny days before applying MN Stainstop to the granite paving and setts.

i decided not to let the contractor use Azpects – Easy Joint on the patio so would like so advice/guidance on how best to point. We have about 100 Sq M or Granite 900x600 thats been laid with 5-6mm joints. Also have granite setts around the paving and paths that have about 10-12mm gaps.

I spent a few hours last night on the site and have come up with a few options:

Gftk 815 for the small 5-6mm joints and the 850 for the granite setts
Larsen GPM Gun Mortar
Ardex Grout

The GftK looks like a great product but i'm a little worried that it will/could stain the silver/grey granite.
The gun mortar looks like a great option with a 5mm gun. the ardex products seem to get good reviews. With the grout would this be placed in a gun or do you use the same process at grouting floor tiles?

i'm hoping that as I've used MN stainstop staining shouldn't be an issue so the GftK looks like the quickest option as long as the paving is kept wet at all time.

Anyone recommend a good on-line supplier that I can order from?

Regards

Paul

[Tony McC]

GftK - use just one product, it doesn't really matter which, but choose just one. Even the 850 will get into 5-6mm joints. The 815 is ideal for joints <5mm

The way to ensure no staining with GftK (and most other 2-part resin mortars of quality) is to abso-bloody-lutely saturate the stone the night before jointing is to be done. Then wet it again in the morning. And again just before applying the mixed mortar. Then add more water while squeegeeing it into the joints. Then rinse off and rinse of and rinse of and rinse off again

You CANNOT use too much water, and the wetter, the more saturated is the stone with water, the less risk there is of any resin taking up residence within the capillaries of the stone.


Gun mortars - a skill very few possess and very difficult to put right *when* (not if, but when) it goes awry.

Ardex - you need to be meticulously thourough with the cleaning. All too often, despite the best efforts of the installers, these exceptionally fine-grained tile grouts leave a residue that, in theory, is a doddle to remove from tiles (or porcelain paving) but can present a challenge on more porous natural stone.

[lutonlagerlout]

I have used 815 with granite recently and as the gaffer says lots of water is the key
LOTS of water
LLL

[ilovesettsonmondays]

Done a few granite patios all 900x 600mm .All were from different suppliers .most slightly bowed. Nustones were definately the best quality if that's ok to say.

[Stanlyp]

Good Evening,

A big thank-you for you advise on the patio. After much discussions with my contractor I decided to do the pointing myself.

I bought a PC Cox mortar gun and 3 bags of Larsen GMP.

I initially sealed the front garden path and the 100x100 cobbles with MN stainstop. That was about 20m2 of 900x600 granite and about 40m of cobbles that went down each side of the path and round our bay windows. The cobbles had gaps around 10-12mm while the paving was laid with 5mm gaps.

The GPM was mixed up and after a few small batches I worked out the right consistency. Managed to point all the cobbles last Sat. Waited for it to nearly go off before striking it with a builders pointing tool. Reall happy with the finish of the GPM. It smooths off very nicely.

Pointing the 5mm gaps on the granite slabs was a different job. Even with the small tip on the PC Cox gun it was very difficult to not mark the slabs. Even with them being sealed the mortar cleaned off easily with a damp sponge but still seem to leave a white film even though they were sealed with MN stainstop.

I had to come up with a new option so off I went to screwfix and bought 100m of aluminium tape. 4hrs later I masked up each 900 x600 paving slabs and then started pointing again using the gun. Leaving the mortar slightly high once the gap was filled and then striking the mortar with the tool left a great finish. Once the mortar had started to go white I removed all the aluminium tape to be left with a great looking pointing!

What I have noticed is that water seems to lay the pointing between the granite cobbles. Should I have used a pointing tool to strike these joint leaving a "U" shape or should these have been left with a "n" shape so water doesn't collect between the cobbles.

Your be please to know that for the other 90m2 I have in the back garden I've bought GFTK 815 which was delivered today as there is no way I was willing to mask up 90M2 with aluminium tape. Ive learnt that using a gun with GPM is a skilled job left for the professionals unless you use aluminium tape !

Gftk 815 should be going down Saturday so fingers crossed it doesn't stain....

Thanks again.

Paul

[Tony McC]

The water hanging on the sett pointing: if it's not a u-profile, nor a n-profile, then I'm guessing it must be flat, in which case, the fall must be tight for water to hang there rather than draining away.

Let us know how you get on with the 815......

[Stanlyp]

Good Evening,

Managed to get 5 x tubs of GftK 815 down today. Thought I'd bought enough but still another 20-25m Sq to do. Just didn't seem to go as far as I thought so will have to order another 2 tomorrow to get it finished.

Can I ask if 850 is an exact colour match for 815 ? Been using stone Grey. My joints are 5-6mm so wondering if I'd get away with one tub of 850. Had very very little waste which was good.

I used loads of water and had a friend round misting it. Some of the slabs are still a little tacky in places even though I made sure the grout was removed. Hoping and praying we have no stains !

Regards

Paul

[Tony McC]

Npo - the colour is slightly different, but the texture is noticeably different. It may not be an issue for you - you'd have to look to spot that it was different, but it would never be a perfect match.