# Lime



## JonM (Nov 1, 2007)

I don't pretend to be a mason, actually I prefer to stay 5o feet from any type of brick or concrete work...I just have a simple question...Why does some mortar recipes call for lime and some don't?...:thumbsup:


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## concretemasonry (Dec 1, 2006)

The original mortar was Portland cement and lime. It is still the standard that other blends are compared to. It is usually more workable and has better autogenious (sp?) healing properties.

Recent mixes have allowed masonry or mortar cements that contain different chenicals. fillers, surfactant (soaps) and by-products to get workability and different properties. From a structural standpoint you can make any type of mortar using combinations of different strengths and cementitious materials.

You can get a wide range of strength from any of the mortars that meet the ASTM C270 requirements.

Contrary to uneducated opinions, higher strength mortar is nor desirable and ASTM suggests using the weakest mortar possible to carry the structural loads. Strength is rarely a criteria for selecting a mortar type. I have had 4800 psi concrete block prisms made using 2200 psi mortar.


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## stuart45 (Oct 7, 2009)

This is the UK National House Building Councils recommended cement mortar mixes. What the hod carriers actually produce is another thing.


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## 4th generation (Mar 28, 2008)

If you are trying to repair an historical building the recipe that is generally spece'd is a 1-1-6 thats 1 portland 1 lime & 6 sand this however is not the original recipe from the days of very old. Prior to portland cement it was pretty much lime & sand (and probably a few other additives by the mason to make it smoother) often horse hair was also added for strength which was later replaced with asbestos, which is why we have to be careful when we repair buildings of that era. The lime that you get in the bags nowdays is only good for plastisizing the mortar and the portland gives it the actual strength. For new construction we now use masonry cement (and sand) which supposedly doesn't contain lime however the actual cement recipes are closely guarded secrets. And there are also regional differences in mortar recipes due to seismic, climate and other factors.


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## Tscarborough (Feb 25, 2006)

You can slake Type S lime to create lime putty, FYI.


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## CJKarl (Nov 21, 2006)

Tscarborough said:


> You can slake Type S lime to create lime putty, FYI.


I have heard of this, I need to try it. Can you explain how you did it?
50/50 water to hydrated lime? let her soak, add water as necessary?


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## Tscarborough (Feb 25, 2006)

Just keep it covered with water, 2 days to a week. It is good so long as kept covered with water.


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## fjn (Aug 17, 2011)

*hydrated lime vs.lime putty*

It is true you can create a lime putty by soaking dry hydrate"bagged" lime. You will improve some of the properties of the lime if you do it. That process will "fatten" up the lime and improve it's plasticity however it will not equal lime putty derived from slaking quick lime and forming a putty directly from that method. If you want to learn more regarding that topic get your hands on the papers presented at the 2005 lime symposim held in orlando fl.that year.Also read the book Building With Lime by Stafford Holmes &Michael Wingate.One can also read the Myth Of The Mix by Gerard Lynch. All the above will shed a very bright light on lime and its contribution to mortar.


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## Tscarborough (Feb 25, 2006)

If you use bagged Type S double hydrated lime and not common single hydrated lime, there is no difference.


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## fjn (Aug 17, 2011)

*There is a difference*

NOT TRUE if you read those publications you would realize that . If you have not previously read them do so and then way in .


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## dakzaag (Jan 6, 2009)

Virginia Lime Works has a pretty good explanation of lime mortar and restoration work. 

All Lime is not for masonry use.

A pretty good example of why you need to know what your doing in this area of masonry is the fact that Portland Cement wasn't invented until the late 1800's. It didn't become commonly used until the 30's and 40's. So if your working on a building from the turn of the century, you are most likely dealing with lime mortar. 

You had better replace the original mortar with similar or your going to introduce problems down the road. 

The addage that Dick mentioned about using the weakest mortar that will still handle the load is critical to the success of masonry. This is a really hard point to get across to most people, carpenters included. 

I have a real close friend who insists on mixing his mud with 1/3 less sand than is called for. I can show him the label on a bag and I have counted shovels with him to prove my point, but since he learned from an old mason, he still doesn't believe me. 

So many ill informed people, so little time...:whistling


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## concretemasonry (Dec 1, 2006)

Those references are local construction using local practices, local materials and traditional tools, but do not apply universally by any means.

A wide trowel will require a different mortar, the local sand may have different shapes that can be more important than the actual "by the book" gradations.

Everyone knows or should know that compressive strength is NOT the main criteria, since mortar types defined in ASTM 270 are just arbitrary proportions in the acceptable to break mortar into different "types" for specifying by proportions. - See appendix 1 in ASTM C270 where it clearly states that workability (which depends on local materials) is the most important property in specifying mortar and workability can be achieved in many different ways. I have made 4800 psi hollow 8x8x16 concrete prisms using 2500 psi mortar.

It all goes back to whether the mortar holds masonry units together instead of apart and all the hair-splitting is often not necessary.


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## Tscarborough (Feb 25, 2006)

"NOT TRUE if you read those publications you would realize that . If you have not previously read them do so and then way in . "

I do not need to read the publications (although I have), I can read a chemical reaction. They are exactly equivalent.


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## fjn (Aug 17, 2011)

*mortar strength*

Mortar strength it appears is akin to the bigger is better mind set. Most mortar speced is way to strong and consequently to brittle. There are certain tech. notes out there That advocate portland/lime mortar.One of the perks they claim is autogenious healing. That IS a wonderful property,however there is a very distinct possibilty that the chance for it to occur in a mortar containing portland is very very slim. In order for that to happen the 'free' lime must be able to "leech" to the surface where it can carbonate. The presence of a pozzolan negates the ability of the Free"lime to do so. Portland is a stong pozzolan the more there is present the less the chance for the healing. In a lime sand only mortar it happens all the time every time.If a small portion of portland is added to a predominately lime based mortar to create a gauged mortar it negates the limes ability to the mortar as a binder. Having said that,that is the reason portland should NEVER be less then 50% of the lime, otherwise the mortar is destined to fail.


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## Tscarborough (Feb 25, 2006)

Sorry, but I disagree for the very reason you state. Speaking of stucco, using 2-10% portland is an excellent way to gauge a lime stucco. For mortar, the same applies, but the type of unit being laid should determine an appropriate percentage, but never more than 10% for a lime mortar by volume. For a portland cement mortar 25-75% is appropriate depending upon the units and structural requirements.


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## Rock Headed (Nov 8, 2007)

Tsar, I was on your side in my "restoration experts" thread.

fjn, my reseaches all tend to totally corroborate your thinking about hydrated lime. Not the same as slaked lime. I soaked some last year...did not make an acceptable lime putty.

Then again, this double hydrate lime is a new term for me. Still, everything I've read indicates bagged lime just don't cut it.

I was planning on that restoration project of mine, considering anyway, using hydraulic lime, rather than regular lime putty. Comes in powder form, from the virginia lime works company I believe someone else mentioned. it is is made from lime stone which naturally contains pozzolanic properties, some alumina silicate I believe. 

Will that negate it's self-healing properties? For those unhip, when fjn talks of autohegdmonious um ation healing properties, he refers to the fact that lime bases mortars contain free unbided lime particle, whicle can and do come into action to fix minor cracks over time. 



I've made myself a whole bunch of mock ups....mixing together all types of stuff.....bagged lime, slaked lime, lime putty......locally harvested clays, koit clay, clay from my yard, fly ash, ect....all attempting to come up with an aternative to OPC. I am not the best scientist, nor an expert on lime in any way! But I try. Ordinary portland cement kinda sucks. It's quick and easy, hence it took over. Much like cheesy assed cultured "stone" and pavers now are taking over. Quick and easy wins, in the short run. OPC is the reed that refuses to bend in the wind, thus breaks. Seriously, I hope this convo continues.


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## dakzaag (Jan 6, 2009)

Here is an article that you might find useful.

This old house has an articlle on line that gives some basic information as well. Google will help you find it.

I haven't read this article all the way through but is looks promising. Well, now I have and I still think it is a good read. It helps distinguish between hydrated and hydraulic lime. 

Virginia Lime Works also has a bunch of info on the topic


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## Tscarborough (Feb 25, 2006)

A valid response. The various names and types do not change the fundamental chemical reaction of lime to water and air though. You can add substances to adjust the various properties, but when dealing with straight CaO, the reactions are predictable and known.

Hydraulic lime mortars contain a gauging material. Lime, CaO, on its own, requires C02 to achieve set. The basis of creating a lime mortar or render is to fully hydrate the lime without providing CO2 to allow it to begin transforming to calcium carbonate until application.

CaO + H2O → Ca(OH)2

Once you have that, the material is ready for use. It doesn't matter how you get there, the desired result is:

Ca(OH)2 + CO2 → CaCO3 + H2O

That is lime mortar/render/stucco, what have you.


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## Tscarborough (Feb 25, 2006)

And just because that is a little confusing, here is a clarification:

Lime mortar is never hydraulic.
Mortars containing lime can be hydraulic.


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## Diamond D. (Nov 12, 2009)

Meanwhile Rock, there is a local outfit, similar to The Va. Lime Works.
I forget their name and address right now, but it is just south of Quakertown.

I will look for it when I get home, in a couple days.
You probably already know about them, but, I just thought I would mention it.

D.


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## Diamond D. (Nov 12, 2009)

Never mind, Rock, S.S. Has it over on your "expert thread"

Figured someone would know.

D.


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## stuart45 (Oct 7, 2009)

All the plasterers I know that use lime mortar for internal rendering won't use hydrated lime. They will only use matured (at least 3 months) lime putty. They say that it's a much better quality mortar. It could be just their imagination, although I can remember being taught something about it at college when I was an apprentice. It was a long time ago but I think that one of the reasons given was that the bags are not 100% moisture free and the lime can carbonate slightly as soon as it's bagged.
In theory it's all the same product.


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## CJKarl (Nov 21, 2006)

I know a mason that uses only lime mortar. He buys Calcium Oxide, mixes it with water in a mortar tub, then stores it in 55 gal plastic drums.


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## CJKarl (Nov 21, 2006)

Can always just make your own.


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## CJKarl (Nov 21, 2006)

Also, look this guy up. One of Europe's top restoration guys. Walking history lesson and a hell of a good guy to boot.
http://homepage.eircom.net/~mcafee/#limew


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## fjn (Aug 17, 2011)

*lime works*

the name is DeGRUCHY Lime Works The owners name is Andy DeGruchy. Quakers Town Pa. The hydraulic lime they import comes from a plant in France called St. Astiers.


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## fjn (Aug 17, 2011)

*lime works*

The name of the co. is DeGruchy Lime Works the owners name is Andy DeGruchy. The hydraulic lime they sell is imported from France & is produced by St. Astiers lime co.


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## fjn (Aug 17, 2011)

DeGruchy lime works Quakers town Pa. Andy DeGruchy owner


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## fjn (Aug 17, 2011)

*trying to post in right spot*

I can't seem to get reply in right spot. The lime works in Quakers town Pa. is DeGruchy lime works Andy DeGruchy is The owner his lime comes from France St. Astiers lime co. it is hydraulic 3 types.


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## fjn (Aug 17, 2011)

Stuart 45 lime does start to carbonate as soon as it is produced . I got that staight from the area rep. for Carmuse lime in pa. he said 6 mo. old it was so so 1yr. toss it. Iknow a guy serving on the A.S.T.M. board who is trying to mandate producers date stamp bags out of 6 in U.S. now only one does so on there own.


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## Tscarborough (Feb 25, 2006)

Lime is hygroscopic, so there is some truth to that.


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## CJKarl (Nov 21, 2006)

Had to look that one up.

Definition of HYGROSCOPIC
1
: readily taking up and retaining moisture
2
: taken up and retained under some conditions of humidity and temperature <hygroscopic water in clay>
— hy·gro·scop·ic·i·ty \-(ˌ)skä-ˈpi-sə-tē\ noun


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## Tscarborough (Feb 25, 2006)

We have some Type SA that was shipped by mistake to us in 2006 in the warehouse. I just opened and sampled a bag. It is still powder. I will soak it for a week or so and see what happens.


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## Rock Headed (Nov 8, 2007)

The state I live in has large known lime deposits. I worked on a job once, new construction where the earth was all lime. Dig down 6 inches and you hit lime, all white, both loose powder-ish stuff and stones.

I'd love to have access to that ground now--back then the lime riddled soil made the excavation proccess as well as re-grading a pain in the neck.

I'll get around to finding another local source one of these days. It would be neato, having that level of involvement with the materials I build with.


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## dakzaag (Jan 6, 2009)

CJKarl said:


> Can always just make your own.


I have been wanting to build a kiln like that for some time. What is the raw material, and how do you know you got it hot enough? 

I was under the impression that the kiln had to reach about 1800 degrees farenheit. Maybe that would be for production purposes.

Carl, did your kiln work and were you able to use the final product with success?


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## CJKarl (Nov 21, 2006)

Yes it worked. In the last pic it is of the quick lime chunks being mixed with water. It made a beautiful lime putty.
This was just an experiment for fun, so I really didn't have a project in mind.
I mixed half the fresh lime putty with sand. 1:3. Played around with some brick and stone. Man oh man does that mortar work nice!
I also put half in a trash bag and sealed it up, left it in a small box I made out of dry laid brick for protection and left it over the winter.
About 6 months later I opened the bag and mixed some more 1:3 mortar and actually used it on a small part of my pizza oven.
The lighter colored mortar is the lime mortar. It set up nice also.


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## CJKarl (Nov 21, 2006)

Raw material were some limestone veneer scraps and 100 year old coal I dug out of a church basement.


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## CJKarl (Nov 21, 2006)

I was thinking of building another one and trying to fire some pottery. There's a primitive technique (forgot the name) of stacking the pottery among the fuel and burning it. Being in contact with the fuel gives the pieces random color variations.


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## stuart45 (Oct 7, 2009)

CJKarl said:


> I was thinking of building another one and trying to fire some pottery. There's a primitive technique (forgot the name)


Is it a clamp kiln? Clamp bricks are made the same way, as it gives them a variety of colours.


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## Fundi (Jan 5, 2009)

CJKarl said:


> I was thinking of building another one and trying to fire some pottery. There's a primitive technique (forgot the name) of stacking the pottery among the fuel and burning it. Being in contact with the fuel gives the pieces random color variations.


Use that pizza oven when the wife aint looking. I am serious. I have seen bricks burned this way on small scale.


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