Coping stones: mortar bond has failed

[mike004]

Moved into a 70s bungalow in December. I was looking at the front garden wall -- a small 4 or 5 course brick wall, about 6metres with taller piers every now and then.

Nearly all the coping stones on top of the brick work were loose and in danger of falling off. I could lift them by hand. I removed most of them for safety reasons as a public footpath is nearby -- a toddler could pull one off and injure itself.

Question: How come most of the coping stones have come loose? A bad mortar mix?

Refixing the coping stones will be my first ever job with a trowel/cement. I have bought a ready-made bag of pointing mortar mix from B & Q. Will this be OK.

Tips please. Getting a level finish shouldn't be of prime importance in this case. I seem to recall my dad always had a bucket of water handy when he did bricklaying stuff...

Mike

 

[kevplumb]

wet the stones before using them

 

[mike004]

>wet the stones before using them<

Is that to ensure the mortar does not dry too quickly and so is prone to cracking?

Mike

 

[Thermo]

first thing id do is scrap the bag of ready mix mortar. invariably its crap and never the right mix. Get a bag of building sand and cement. Get a small bucket and use a 1:3 mix (3 parts sand 1 part cement) fill the bucket level 3 times with sand and then once with cement to make sure you get the right mix. Mix it all up dry and then start adding the water to get the right consistency (fairly wet, but still firm enough that it wont slop about)
wet the coping stones and the bricks that they are going on top of. Let them dry a little around the edges so the mortar doesnt smear. Place a nice dollop of the mortar on the brickwork pier and run the trowel through it to get the bed spread roughly even. Place the stone on it and give a little wiggle of the stone as you do. Square it up and then strike the mortar thats overhanging off with the trowel to get a neat finish. About an hour or so later you can point it up if you want.

In answer to your other question the bricks and stone are wetted to ensure they dont suck the mositure out of the mortar too quickly so that it bonds well. You dont need to do this so much on a damp day.

Best of luck, and ditch that ready mixed stuff

 

[Simon Ruddy]

Before setting the copings back onto the wall, mix a slurry made up of dry cement, SBR and water and paint this slurry onto the underside of the copings. While still wet refix the copings as normal.

More reading here => http://www.pavingexpert.com/sbr_01.htm
and => http://www.pavingexpert.com/bond_bridge_01.htm

 

[23vc]

Excellent. Having been trying for the last 14 years, they’ll be glad of that advice

 

[23vc]

Excellent. Having been trying for the last 14 years, they’ll be glad of that advice

 

[VDubDan]

Excellent. Having been trying for the last 14 years, they’ll be glad of that advice

 

[VDubDan]

Excellent. Having been trying for the last 14 years, they’ll be glad of that advice.

Edit: Looks my mockery has backfired somewhat!