Monthly Archives: January 2012

Masonry walls or concrete columns?

If you are looking for concrete explanations to choose the right one, read these rationalizations.

Is your house built with pillar construction? If this line sounds familiar, there’s no surprise. Among larger cities today, building the house with concrete pillars and beams is becoming common, just like a multi-storey office building gets built. Have the load bearing walls suddenly lost their capacity? No way, they are as good a system as ever.

In the older areas of any city, houses with two or even three floors are commonly found built with no pillars. Raising the house, wall over the wall and floor over the floor, has been the most common method all over the world. The system is termed ‘load bearing wall system,’ against the ‘column and beam’ method called as ‘frame system.’ Both the systems have their respective advantages and drawbacks, hence require a judicious synthesis, as specific locations demand.

Pillars become inevitable where the soil is very loose, ground is water logged, land is earthquake prone, masonry materials are rare, and light weight construction is desired. A simple criterion for taking a decision can also be to see how our elders built. Irrespective of the site context and precedence, today we see the proliferation of concrete pillars everywhere. Construction costs have gone up, yet the idea has caught on!

The myths…

Among the arguments supporting RCC columns, we hear that more the columns greater the safety against earthquakes. It is not totally true, for structural stability against earthquakes depend upon basic principles such as corner stiffeners, diagonal bracing, height proportions, and horizontal ties. If such issues are not adequately addressed, a framed building is bound to crack or collapse as much as a walled building would.

Another myth is about the reduced cost due to thinner walls, again not fully true for additional costs of the concrete components nullify the masonry savings, where thin walls bring more noise and water seepage as fresh set of problems. Additionally, framed buildings demand alignments to perfection, skills of construction and good junction between materials which are most often missing.

The major two arguments for framed buildings could be the speed of construction and possibility of tall structures. While these two are essentials of multi-storeyed buildings, they are inconsequential for houses, where time saved by columns is negligible considering the time anyway consumed in finishing the house and the advantage of possible height may not be the criteria, for houses are rarely beyond the second floor.

The professionals and the market forces together have misled building owners, erecting RCC columns everywhere irrespective of their real necessity, in the name of durability and strength. Now the time has come where even people simply demand concrete pillars, converted to believe in the myth that they are better. It is high time we realise how RCC frame for houses consume more money, resources and energy, none of which benefit either the building owners or Mother Nature.

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Why are we happy to cut the trees?

We may not be able to make our cities more green, but the least we can do is not to make them less green.

As we read about terrace gardens and green roofs, the real green roof we have above us in the form of the tree canopy and thick foliage is thinning. When we notice trees getting hacked for unconvincing reasons mainly with a don’t-care attitude, all our talk about passive cooling that is being written for several weeks now seems a contradiction to what we otherwise are doing – creating heat islands and not cool cities.

While passing by a road, if there is a road block for cutting a tree, what would you do? Mostly we take the diversion and dash off to our destination. In this case, one felt like pleading with the site owner (who had requested for cutting the tree) checking how happier the neighbours will be without the tree and arguing with the officials about the whole system that lets people get the trees cut.

All that one could do was to photograph this great tree-cutting ceremony, gleefully watched by many people including the officials who appeared individually concerned, but had to follow the orders of the higher ups. It pains that one hour of arguments just went in vain.

After a year long effort with repeated applications and official refusals by the forest department inspectors, the owner was finally proud that he could get the local politicians to support his plea for cutting the tree. What was most hurting was to realize that there was no serious reason to cut it off, except that the roots of 50 year old tree were affecting the sanitary lines of his 20 year old house. It could have been simply solved by an RCC screen wall between the tree and the house to stop the roots growing towards the house. Instead, imagine cutting off the tree itself! Interestingly, we all claim to compensate for our wrong doing, like the house owner in this case assuring to grow fresh trees in front of the house. With the kind of urban life we all live in, with no time to stop by to look at how the leaves of a tree look like, with no mechanism to ensure that the sapling will grow undisturbed for 5 years and with the shallowness of the assurance to grow which follows the happiness to cut, we all know that replacing trees is easier said than done.

Quoting here from the 1854 speech of Chief Seattle may appear like an over reaction to cutting of one tree, nevertheless, these quotes do remind us about our possible destiny. “Where is the thicket? Gone. Where is the eagle? Gone. The end of living and the beginning of survival.”

We may not be able to make our cities more green, but the least we can do is not to make it less green. If we can not solve the problem, at least, we should not add to the problem.

Back to the past, for a stable future

The vernacular architecture of yesterday is the net zero carbon building of today.

It is now nearly proven that to relook at our past, pick sustainable ideas of every region and apply them appropriately during construction makes more green sense than many other material and technology driven solutions. The vernacular architecture of yesterday is the net zero carbon building of today. If so, returning to the past could be the ultimate solution towards a sustainable future. Of course, we all know, this sounds too simplistic for our times have drastically changed, the quantum of construction has grown manifold beyond the reach of traditional methods and in many areas the local materials or expertise could be in short supply.

However, if we observe our reactions to the past, we realise that not many fingers are pointed to the past saying traditional ideas are invalid, indirectly suggesting that the problem could be lying in applying and operationalising them. At the deepest level, however, we need to understand that the root cause lies in nobody patronising the spirit of the past today.

Overhead tank

A simple example could be to narrate the story of the overhead water tank. Traditionally, they were built with bricks, plastered and painted. Of course, there were issues such as leakage if they were not properly constructed. When the PVC tanks appeared in the market, the brick tanks were relegated to the backseat quoting examples of leakage or construction time, which actually need not be the core issues. Incidentally, the PVC tanks cannot be fully cleaned, water gets hot during summers when actually we desire it cold, create a problem if the pipe joints leak and are not necessarily cheaper. Yet, today we see PVC tanks everywhere!

During the complete cycle of the product, numerous people are involved starting from the raw material suppliers and manufacturers, carrying and forwarding agents, stockists and wholesalers, sales agencies and retailers, and finally, builders and installation team. Everyone needs a share in the profit chain; hence each one aggressively promotes the product through printed brochures, sales personnel, trade discounts, websites, promotional gifts, event sponsorships, newspaper advertisements and every other means available. What counts here is the sales figure and not carbon emission or embodied energy counts.

It is the same story with lime coat vs. chemical paint coat, mud block vs. cement block, oxide floor vs. vitrified floor or digging an open well vs. drilling borewells. While we know all about brick tanks, lime, mud, oxides or open well, with no one talking about them, it’s but natural that they get relegated.

No dearth of ideas

There is no dearth of eco-friendly ideas and construction options that could be discovered from our local tradition which can compliment the recent research findings, modern design ideas and new superior materials. No one argues for doing only what our ancestors did, and the need to blend the past and present has been widely accepted. To that end, traditional concepts also need to be popularised and local materials also need to be promoted.

Let us have green and cool roofs

The focus area of the ‘Green Sense’ column has been eco-friendly and energy-efficient ideas towards sustainable futures. Vegetative garden is being discussed here as one of the means of achieving that objective, including passive cooling of buildings. 

Going by the mail response ‘Green Sense’ column received during the last few weeks, one wonders why we do not get to do what is close to our dreams. The terrace suddenly appears to be a potential unexplored, with pavilions and gardening being what many house owners dream of! If it is true, we need to realise what has been the obstacle for following one’s dreams and find corrective solutions.

Incidentally, the focus area of Green Sense has been eco-friendly and energy-efficient ideas towards sustainable futures; as such, vegetative garden is being discussed here as one of the means of achieving that objective, including passive cooling of buildings. This idea of terrace garden is not to force residents to divert their time towards vegetable cultivation. We are living in the age of busy schedules, with no spare time; as such, expecting everyone to grow vegetables as a weekly norm surely sounds far fetched.

Multiple advantages

So, when a reader responds asking how practical it is to expect people to do rooftop vegetation, the answer can be guessed without stating it. However, there could be many people who generally stay at home, who may take to it as a pleasurable hobby. Having said this, we need to discuss vegetative roofs, not only for the ecological benefit, but equally well for the multiple advantages they offer — exercise for the body, livelihood for gardeners, home-grown vegetables or a place for family relaxation.

In case it is an existing building with no hollow core slab and we have no time to do greening of the roof, what do we do? Give up on passive cooling? Not really, there are other excellent ideas such as painting the roof white. This cool roof concept comes from the proven fact that white colour reflects light and absorbs less heat, hence keeps the building interiors cooler. Nowadays, the cool roof concept is being popularised in green building circles, it being the easiest step towards reducing heat gain in buildings. There are special paints available which are made to reflect more heat; however they may cost more.

The traditional lime wash

Traditionally, many villages in hot, arid regions are known to lime wash the house walls and often the roof also every year as a festive preparation. This practice might have begun both as a strategy of annual maintenance and also passive cooling. Lime being a common material and economical, a coat of white lime with small quantities of blue to tone down white-brightness and a pinch of salt to increase surface density of particles is among the simplest, cheapest, and easiest solutions in the Indian sub-continent.

Unfortunately, this century-old wisdom is also among the ideas vanishing at the fastest rate, since no manufacturer, no company, no advertisement and no website is promoting local lime coat!