Liscannor slate with a Kilkenny blue limestone gully surround, all pointed using a lime mortar
from Tony McC Posted: 04 May 2006,14:02
After going through the issues regarding achieving a light coloured jointing, to resemble the kind of colour that Kiln dried sand is when first laid. I tried the suggestions using a lime mortar. The mix I used was 1 part cement-1/2 lime-4 1/2 white sand.
The lime mix ratio I used I took from the table on the web site.
I used the mix in the corner as a test, unfortunately the joints are now hardened to a gray colour. Is there anything I can do. Or what am I doing wrong.
Many thanks for your help. ???
Aaaarrrggghhh! The mortar recipes given on the website are for mortars were the lime is a plasticiser, rather than the binding agent. What you have is basically a lime-modified cement mortar, not a lime mortar. For pointing, I'd suggest a 3:1 mix of coarse sand with hydraulic lime. If you need a fast set, then 6:2:1 sand/lime/OPC.
As with much else, this is a topic whose coverage on the website I hope to expand in the coming months, but my time is sorely limited by other committments, not least of which is the need to earn a living!
