Tuesday, August 25, 2015

Lime use in buildings

Welcome to our blog, Menfranco general blog
and this post, lime use in buildings
Lime use in buildings
When mixing mortar, we not only use cement, but we use also lime, in fact in the old times lime was the main ingredient that was mixed with sand to make mortar. Of course there are other uses also, where lime is needed, as we are going to write about in this post.

Lime use in buildings

Quick-Lime and slacked or hydrated lime

Dear readers, in this post let us talk about the, Lime use in building and other uses as well, just to show you that lime is one of those things that is very useful and has been used a lot more than we normally think, but let us see what we can write about it. 

Today when we talk about lime we see a bag of white powder that we buy at the hardware store, we know that we can use this powder to replace some cement in some cases when we make mortar, but we don’t seem to know much more than that, But lime is a lot more than just a white powder in a bag, because lime is one of those materials that has been and is being used a lot in many ways, its’ largest use is in making mortar for the master builders, but it has many other uses also. So first of all let us talk about lime and where it comes from, so that we would be able to understand a few things about lime process and its several uses, of course here we are mainly interested about its use in the building industry for making mortar etc. But there is a lot more to say about lime, but before we do that let us check out how the Wikipedia explains quick-lime etc. Where you can find a lot of information about lime if you care to know all you need to do is click on the links therein.

And then we will say something about how in the old times quick-lime was turned into slacked lime for the builders and other people to use.   


From the Wikipedia:

   Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely usedchemical compound. It is a white, caustic, alkaline crystalline solid at room temperature. The broadly used term "lime" connotes calcium-containing inorganic materials, which include carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate, such as limestone. By contrast, "quicklime" specifically applies to a single chemical compound.

Quicklime is relatively inexpensive. Both it and a chemical derivative (calcium hydroxide) are important commodity chemicals.

   Calcium oxide is usually made by the thermal decomposition of materials such aslimestone, that contain calcium carbonate (CaCO3; mineral calcite) in a lime kiln. This is accomplished by heating the material to above 825 °C (1,517 °F),[5] a process calledcalcination or lime-burning, to liberate a molecule of carbon dioxide (CO2); leaving quicklime. The quicklime is not stable and, when cooled, will spontaneously react with CO2 from the air until, after enough time, it will be completely converted back to calcium carbonate.

Annual worldwide production of quicklime is around 283 million metric tons. China is by far the world's largest producer, with a total of around 170 million metric tons per year. The United States is the next largest, with around 20 million metric tons per year.[6]


As we have said above, lime has been used for a very long time its use could be prehistoric, nobody seems to know when it was first used in making mortar and plaster for buildings and also for other things, it was/is used even to disinfect places when there is no much else to use, and I know that there is a lot more to say about the use of lime even today; up to the time when I was young it was used even to whitewash the walls in spring once a year, after a long winter all the walls would be all darkened with smoke, since then if you wanted to keep warm you needed to light a fire in the chimney, so some of the smoke of the fire would find the way into the rooms instead of going all up the chimney, I am pretty sure that even today this would be the cheapest way of cleaning rustic building, as, it is one of the cheapest ways to make everything clean. But let us start to tell you it several uses including as a building material to make mortar when I was young, as it was done then and how I have witnessed it done and in rare occasions helped to do it myself, just to bring water to the pit.


From quick-lime to hydrated lime

From quick-lime to slacked lime the old ways

Here we are going to talk about the late forties and early fifties, when I was young and learning what was happening around me, so, here under we will be writing about what I saw and learned at that time about lime products and its uses. 

In the town where I come from in southern Italy; in the early fifties when there was a new building to be build or some alterations to existing buildings to be done one of the first things we would see was that the master builder would get ready a good supply of slacked lime, because this was one of the most important building materials he would need to do the job. In those times bagged hydrated lime and cement was very expensive, and also bagged cement has a short life shelving span, as it reacts when humidity infiltrate the bags, therefore most people or builders that needed to build would use lime wherever they could; they would buy quick lime and get it process immediately on delivery themselves or with the help of the people that delivered it, of course one needs to know how to do that, because there is some danger while you are doing it, so let us see how it was done, and then we will also see where else the lime was used.

So; the master builder would get ready to do this; if he had some large container or a purpose made pit he could use them, otherwise he would build a square wall like a box and in this large box he would process the quick-lime, now the quick lime cannot be held the way it is for any length of time, because it reacts to humidity and violently to water, so it is necessary that it is turned into slacked lime as soon as possible after delivery.

 Okay, the cart or the lorry is on the way, so the master builder gets his worker to start filling the pit with water, and when the quick lime arrives they start carefully throwing this burned lime stones into the pit in very small quantities, as soon as the quick lime comes in contact with the water it reacts and the water starts boiling, everybody is banned to approach the pit accept the people that need to work there, and they ware some protective gear, because it is dangerous to handle quick-lime and around the pit, this process goes on until all the quick lime is thus treated, once they have done that it is left to cool down for a few days; after it has cooled down it is a lot less dangerous, but still you need to be careful near the lime pit. You see the lime pit is now filled up with slacked lime, which looks like curd when you make cheese, but it is still very dangerous and it can easily kill you if you fall in it, its contend must be handled with caution, but anyhow the slacked lime is now ready to be used, this is how the builders used to get ready the lime to make mortar. Now to use this lime to make mortar might be a bit different than using bagged hydrated lime or cement; so we will come back to that soon enough, as now I would like to talk about some other lime use first.


Lime use in farming

As we have seen lime is a very useful commodity, in fact they are countless places where we could use it, I only happen to know a few of them but there are a lot more, so, let me just say a few things about how we were using lime in our small family farm at the time when I was young, just the way I remember it:

We would use it just like the builders use it when we had to repair or replace a few stone that were falling apart in the old stone building, so, instead of using a sort of clay that had been used the first time, we would mix a small quantity of mortar using lime and sand, but that is what most of you would already know. We used lime to whitewash the farm house, the stables, the pig stay, the chicken coop and sheds or other buildings near the farm house once a year in spring.

We would use it sometimes to disinfect stagnant water ponds that showed signs of vermin or the water were to dirty, so we would dilute some lime in water and then pour it in the water ponds, and next day the ponds would be clean, as the lime would kill the vermin and also would make the water clear because all the dirt would sink to the bottom of the pond; you see in our small farm we used to have a kitchen garden, so we would dig up a few ponds beside the garden that would feel up with water during winter or when it rained, we used this water to water the plants when the soil was becoming too dry for the garden plants to grow.

In the farms of those days lime was also used to spray vines and trees, sometimes there were diseases that could be controlled by applying a coat of lime to the trunk of those trees; but there is one thing that always comes to my mind; it is when we where spraying the grape vines with a copper sulphate and lime, we would have two containers one with diluted copper sulphate and one with diluted lime, some people used to spray first with copper sulphate and then with lime, so that they somehow would help each other to kill the mildew, but my grandma had worked a way how to avoid this double spraying and it worked thus;

In those times it was not like today and even the vine spraying pump was a devise that you would put on your back and with a handle that you would move up and down you would spray your vines and trees as well; this devise would hold about three gallons of liquid, so every now and then you needed to fill it up; so as I have said we had two containers one holding diluted copper sulphate and one with diluted lime; (of course you had to know how much diluted you had to do your mixtures but that does not mutter here this time) anyhow when the pump was/is empty you would go to these containers to fill it up: here is my grandma way to avoid to spray twice, when filling the pump, first of all you had to make sure than the mixture were well stirred, then you would put the copper sulphate in the pump and at the last minute you would add the lime, and immediately start to spray. This was my grandma way and it worked because the mixture would not have time to settle down and become stale.

There you are this is just another way of how lime is useful in the farms. And now we are going to tell you how to make mortar with slacked lime.

How to make mortar with slacked lime

This is how I know it was done in the old time, perhaps for thousands of years, anyhow let me just describe to you the procedure; We would like to do that so that people that want to try how to do it yourself, could have a go and also in those parts of the world where are far behind may come handy to know, since lime being cheaper than cement and having a longer storage life once it has been hydrated might be more convenient to use than cement. Now that we have stated the purpose of this article, let describe how it was done.     

Let us suppose that you have the slacked lime in the pit or in a container; you also have some brickies loams or very fine sand, so let us start:

First of all make a hip of your sand on a platform and definitely not on loose soil; now that you have done that, make a well in the centre and place your slacked lime in it. The quantities in here may vary a lot more than when we use cement or hydrated bagged lime, because the slacked lime can be as liquid as thickened cream to as compact as feta cheese, so you have to learn as you go about the quantities, but if you have mixed mortar before you soon work it out yourself, or if there is any tradesman that is going to use the mortar he would be able to tell you just by looking at the mortar being done, whether you need more lime or more sand and water etc.

Okay, now that you have the lime in the middle of the sand, with a Larry start pushing this devise up and down through the lime by adding a bit of water as needed and slowly mixing some sand with the lime; you need to do this until you have mixed the whole lot evenly. This is hard work but that is how it was done when there were no mixer and no bagged hydrated lime around.

Here we need to note that this mixing of slacked lime to mix mortar is completely different from mixing other mixture, because the slacked lime is already wet and it is like a paste, and the others are dry powder, therefore it needs to be used in a different way.

Anyhow this is how I remember it was done. Now, I think that I might have said enough about how to mix your own cement or mortar, and also this article has become too long to continue, so see you next time with a different subject about any sort of buildings or real estate. 


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Lime use in buildings
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