Sandstone problems

Patio flagstones (slabs), concrete flags, stone flags including yorkstone and imported flagstones.
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psmudge
Posts: 2
Joined: Thu May 19, 2011 1:15 pm
Location: wales

Post: # 63690Post psmudge

hi i have laid a small patio 3mx4m using indian sand stone and a semi dry 5 to 1 mix tamping down the stone with a rubber hammer,6 days later i went to grout it, to find that i could lift up a number of the stones (most of them)is this normal, i used a dry mix because i was told a wet mix would stain the sandstone
ps the cement has set but is a bit flakey
hope you can help
phil
phil

DNgroundworks
Posts: 1951
Joined: Sat Dec 06, 2008 10:28 pm
Location: Preston, Lancashire

Post: # 63697Post DNgroundworks

well if the flags weren't rocking then there's no real problem, why did you lift them up? personally i prefer a slightly wetter mix to aid adhesion, sometimes we use a bond bridge as well.

I think that a dry mix or semi dry mix and indian sandstone dont work so well together, but thats my opinion gained from my own experiences, alot will say that semi dry is fine.

psmudge
Posts: 2
Joined: Thu May 19, 2011 1:15 pm
Location: wales

Post: # 63706Post psmudge

thanks for that reply, two or three of them had a slight rock so i thought i wonder? thats when i found they would lift, this is only the start of the patio a small raised section, i have another 20m2 to do this was just the tester, i think i will try wet from now on and do it bit by bit.
phil
phil

mike builder/landscaper
Posts: 155
Joined: Tue Jun 22, 2010 9:03 pm
Location: north yorkshire

Post: # 63712Post mike builder/landscaper

i use a mix of 5 parts sharp sand 1 part yellow sand and a cap full of mortar plastisicer. this is mixed wet almost like bricklaying mortar. spread a full bed the size of your paving flag you are going to lay on the floor and make deep ripples with your trowel accross the bed and lay your flag. i always have a bucket of water to hand and an emulsion brush then any spills of mortar are cleaned up instantly. definatly get good adhesion laying with this method.
m.atkinson

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

Post: # 63717Post lutonlagerlout

mike builder/landscaper wrote:i use a mix of 5 parts sharp sand 1 part yellow sand and a cap full of mortar plastisicer.
no cement mike <cough cough>
LLL ???
"what,you want paying today??"

YOUR TEXT GOES HERE

mike builder/landscaper
Posts: 155
Joined: Tue Jun 22, 2010 9:03 pm
Location: north yorkshire

Post: # 63726Post mike builder/landscaper

sorry, forgot to add the cement in the mix. but i think the guy got the jist off what mix i personally use.
m.atkinson

Kristina
Posts: 3
Joined: Thu May 26, 2011 9:50 am
Location: Surrey

Post: # 63968Post Kristina

Sorry wrong thread, don't know how to delete it!
wannabe-builder

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