Some time back it had become common for pundits to talk about brick and mortar or click establishments as though they are mutually exclusive. As a matter of simple fact, it has been proved beyond a doubt that, they are not. This point was recently driven home by the well-received news of the acquisition of Whole food Inc. by Amazon.com.There is no doubt, then that brick and mortar enterprise are here to stay .Which is why its high time we said a few great things about mortar per se.
When you are constructing a building wall you need material that can hold together the bricks, stones or concrete blocks and the courses. That material is mortar- which happens to be an aggregate mix of sand and cement. When this super combo is mixed with water, a chemical reaction –hydration- takes place causing the mix to set. Because this is a chemical, not physical reaction, mortar that has set cannot be diluted by adding extra water to make it easy to work with if has too much cement. The chemical reaction has already occurred and any additional water will only work against you by reducing the long term strength of the mortar.
An alternative to above recipe, is the aggregate mix of sand and lime plus water. This formula gives mortar that sets through a process called carbonation- in which the lime hardens by absorbing carbon dioxide from the atmosphere.
However if you need the best mortar, you got to use an aggregate mix of sand, cement, lime plus water. The inclusion of lime not only makes the mortar more elastic and easier to work with but also improves its ability to accommodate movements caused by weather related heat loss and gain.
Mortar strength is varied by increasing the proportion of cement in the aggregate mix. However weak mortar is preferable because it experiences small shrinkage on setting and can cope well with movements caused by weather related heat and moisture variation in the environment. Also weak mortar results in minor cracks at joints which can easily be repaired.
Mortar that is too weak is an albatross across your neck because it’s easier for water to penetrate and can crush under high compression loads. This alone can the reason why your building may pose a high risk of collapse.
©2017Copyright: East Africa Little Hardware Ltd
Sources: Construction of houses by Duncan Marshal and Dereck Worthing