lime mortar mix

[arl]

Hello, just a quickie about mortar mixes

We have just dug up the concrete slab surrounding the back of our terraced house to install an air brick or two (see previous posts). The brickwork at ground level and below needs a bit of repointing before i put down the new patio slabs. Now i know i should use a lime mortar to prevent further damage to the bricks but im concerned that it wont have enough time to set before it gets covered over. Can i use a hydralic lime or will that make it too hard?

On a non-period note, is there any reason i couldnt use the old concrete slab as hardcore for my new patio, or would it make the surrounding beds to alkaline for my plants?

Thanks

 

[David Q]

Hydraulic mix would be fine, it sets in the presence of water (which a non hydraulic wont). However the bags of lime from a builders will be OK this is normally a weak hydralic mix. As long as your ground isnt saturated with water it doesnt really matter.

Concrete is OK in a rockery unless you want to grow alkaline haters (heathers). If the broken bits look too raw, paint them with watered down yoghurt (or cow muck is you have access to it!), this will encourage the green stuff to grow and camoflage it.

 

[arl]

Thanks for replying, i clearly didnt explain myself very well. the concrete rubble is to go below the patio slabs to stop them sinking into the clay so you shouldnt be able to see the stuff.
However the clay is really heavy (you could make pots with the stuff) so the ground will always be quite waterlogged. I wonder if the mortar would set? how long should it be left to harden before relaying the patio?

 

[Gervase]

Stuff like Castle's NHL 3.5, which almost every branch of Jewson's seems to stock, will set impressively as a mix- as anyone who's ever left a bucket of it unattended for a few days will testify !