Laying black limestone.

[sy76uk]

I'm going to be laying a pretty basic footpath and patio at the weekend.

There's only 15m2 on it. It's sagar black limestone, 900x600 and 35-50mm thick for the most part but there are smaller sizes in there. ( random crate )

I'll be pointing it with grey weather point .

I've never laid any limestone and from what I've gathered it's a pain to keep clean.

Also 900x600x50mm slab of stone is going to be a git to get level on a mortar bed.

Any tips from you stone masters out there would be welcome

[r896neo]

Personally i like a good wet mortar with plenty of plasticiser as it flows better under a big slab. Just normal bedding practise though.

The 900x600's are generally similar or a fraction lighter than a council grey 2x2 so prob not as heavy as your expecting.

Keep a bucket of clean water and a sponge handy.

[sy76uk]

Personally i like a good wet mortar with plenty of plasticiser as it flows better under a big slab.

Just the kind of tips I was looking for. I didn't think to use a plastiser.

Just a basic sharp sand and cement mix or bang a bit of building sand in there too? I'll be mixing 6/1.

[London Stone Paving]

Sagar is sandstone not limestone. You should easily be able to tell the difference. Sagar black sandstone is notoriously riven and uneven, unlike black limestone which even though is a riven product, has a fairly flat surface

[sy76uk]

I'm no where near as experienced with laying natural stone as the majority of the pavers that use this forum. I've been a paver since before I left school but the vast majority of my work has been in the commercial sector which meant that we screed and lay more or less everything.

I've laid plenty on a full mortar bed and over the years have done a fair few natural stone projects, setts and flags but it's not something I do day in-day out like most on the forum.

I did ask behind the counter if it was a sand stone or a lime stone and they did say it was a lime.

This one will be nice little job to get used to laying the stuff.

I'll be fine when it comes to setting out, keeping my lines straight, pointing, ect. It's just little tips I'm after.

This was laid on a full mortar bed and pointed with a 3-1 wet mix
[img]https://farm3.staticflickr.com/2844....mg]20140318_174637 by sy76uk, on Flickr

[lutonlagerlout]

we use SBR instead of plasticiser 100ml per mix

half a bag of dust and 10 big shovels of grit sand

like neo wetter than bricklaying mortar as the type 1 pulls the excess water out really fast

if it is black sandstone better tell them it wont be black for long

LLL

[sy76uk]

I've read about SBR but have never used it. Would I get it from any builders merchants or would I have to order it in? I'm a bit weary about sticking it my mixer TBH.

Half a bag of cement to ten shovels is more or less the same as I'd use for the bedding mix.

I always use a fairly wet mix anyway just so that the slabs are stuck down better.

Thank's for the advice Tony.

Why won't it stay black for long?

[lutonlagerlout]

because it will go dark grey then light grey

I posted some pictures a while back let me see if i can find them

LLL

[lutonlagerlout]

limestone

sandstone fades even quicker

if they want black to stay black it would need to be slate i believe

I am sure steve from LSP would have a better answer then this

cheers LLL

[lutonlagerlout]

sorry found my pictures

fade to grey

LLL

[sy76uk]

Thank's Tony. I'll let them know it's best sealed.

[Tony McC]

I did ask behind the counter if it was a sand stone or a lime stone and they did say it was a lime.

I'd be extremely wary of buying *anything* from some dimwits who don't even recognise the difference between sandstone and limestone!

What if they send you bags of board finish instead of OPC?

[sy76uk]

To be fair Tony the place I'm getting my stuff from is a very good stone merchants. It's Alexandra stone and part of the stone craft company. I asked the lad on a busy Saturday morning so I'll let him off.

[London Stone Paving]

In all fairness if its Sagar black sandstone, then its not even black in the first place. See picture

Sagar black sandstone

As Tony says slate is the best option for a dark material that will stay dark.

Black limestone is also good but needs to be sealed with a colour enhancing sealant to keep it black

[sy76uk]

dropped a massive bollock on this job. I brought a crate that say's it covers 15.25m2 of stone but I didn't read the fine print that says it includes a 20mm mortar joint so the laying pattern I set out is 4.4m2 short.

The place I got the stuff from isn't open on a sunday and I have a digger and a skip going to a job I'm supposed to be starting Monday.

Nobody to blame but myself.

We live and learn.

Shit.