chuckey
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http://www.nationallime.org/IBLS05Papers/Induni.pdf
Please don't shout at me.
Frank
Please don't shout at me.
Frank
- Thread starter chuckey
- Start date
I won't shout at you Frank!
An interesting read, so thanks for the link.
The book that got me interested in conservation was by Hugh Lander
An advocate of those very same OPC : Lime : Aggregate mixes.
I've had my fair share of failure working with lime, hydraulic and non hydraulic mortars. I still think that I'd steer clear of using OPC on my particular house, as I've found no evidence of it in the original construction.
Some re-pointing was done at least 50 years ago (before my neighbours moved in) and that certainly seems to be OPC based - it's hard enough, but without a lab test who knows. More recent hard grey cement pointing on the extension gable does appear to have accelerated erosion to the stone, but I can't prove it as I don't have 'before' photos (or postcards!).
I'm more inclined to try a pozzolanic mix with non hydraulic lime, as it seems to be a 'safer' and more predictable option to the alternatives, according to everything I've read to date, and seemingly backed up by the Strange History of the English Lime Revival.
Nice find!
An interesting read, so thanks for the link.
The book that got me interested in conservation was by Hugh Lander
An advocate of those very same OPC : Lime : Aggregate mixes.
I've had my fair share of failure working with lime, hydraulic and non hydraulic mortars. I still think that I'd steer clear of using OPC on my particular house, as I've found no evidence of it in the original construction.
Some re-pointing was done at least 50 years ago (before my neighbours moved in) and that certainly seems to be OPC based - it's hard enough, but without a lab test who knows. More recent hard grey cement pointing on the extension gable does appear to have accelerated erosion to the stone, but I can't prove it as I don't have 'before' photos (or postcards!).
I'm more inclined to try a pozzolanic mix with non hydraulic lime, as it seems to be a 'safer' and more predictable option to the alternatives, according to everything I've read to date, and seemingly backed up by the Strange History of the English Lime Revival.
Nice find!
Lime
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- 2,749
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- East of England
The link in the pdf is interesting too.
http://www.buildingconservation.com/articles/lime/hylime.html
The big discussion appears to centre around whether or not building workers follow their own rules or those given them as specification.
Much like today I suspect they use what they are given and complain bitterly if the mix doesn't behave on the trowel as they like or expect.
Equally, much like today, the mixing of the mortar is thought to be a lowly job and is given to the inexperienced, unknowledgeable and often uncaring, unthinking apprentice. They are only concerned with going home usually.
So I gather from what is written in the pdf that all the written evidence of how much lime, OPC (ordinary portland cement) etc used in making mortar is to be taken with a pinch of salt too?
Probably.
However, no matter what anyone tells me, I judge a mortar by my own experience.
Put very simply, OPC gives a hard ungiving set, lime gives a slow soft set and over time I prefer lime to look at.
Reclaiming stone, brick etc is much easier with lime too.
No contest really.
http://www.buildingconservation.com/articles/lime/hylime.html
The big discussion appears to centre around whether or not building workers follow their own rules or those given them as specification.
Much like today I suspect they use what they are given and complain bitterly if the mix doesn't behave on the trowel as they like or expect.
Equally, much like today, the mixing of the mortar is thought to be a lowly job and is given to the inexperienced, unknowledgeable and often uncaring, unthinking apprentice. They are only concerned with going home usually.
So I gather from what is written in the pdf that all the written evidence of how much lime, OPC (ordinary portland cement) etc used in making mortar is to be taken with a pinch of salt too?
Probably.
However, no matter what anyone tells me, I judge a mortar by my own experience.
Put very simply, OPC gives a hard ungiving set, lime gives a slow soft set and over time I prefer lime to look at.
Reclaiming stone, brick etc is much easier with lime too.
No contest really.