Window Grill & Waterproofing

How does a window grill affect the waterproofing of a building?

Since the serial blast on 12th March 1993 personal safety came on anvil. The day to day life of individual changed drastically thereafter. One significant change which took place was installation of MS Grills on window and balcony openings. Perhaps the family staying behind these grills felt that they were now safe, not knowing at what price this safety is achieved. Over night many buildings voluntarily confined themselves into jail like structure. Taking advantage of the situation people extended this grill to a cage, encroaching 2 to 2 ½ feet space in the air.

Just to get a feel of what people think of these grills I asked few questions to those who were around me and known to me. In short following were some of the answers I got from them –

I. “every one does it, so I have done”

II. “I feel safe, house breaking won’t take place now”

III. “It is necessary, I have small children in my house”

IV. “since grill is there I can keep some flower pots”

V. ”I had to make a place for my split A/c; where else I could have made it?”

Not a single person gave me the answer which I was expecting and that was, “I get an extra space to dump discarded corrugated boxes, plastic buckets and other scrap, children’s broken bicycles and all unwanted heavy items, waiting for the disposal.”

It is an irony that in a country where aesthetics and beauty is cherished for generations is fully ignorant of how they are defacing their city. The authorities are just not bothered; condition is like a free hand to every body, do what you like. If the grill was essential then they could have standardized the size, material, shape design and could have kept the drawbacks within limit. Such cages like box grills which extend out to 2ft. from the wall surface, are installed from ground floor to any floor up in air.

Grills reduce service life of a building

Aesthetics is not an only negative aspect of this practice, installing such grills create a maintenance problem for a building and reduce its service life.

When an architect conceives a design and shape of a building, he approaches Structural Consultant to design a skeleton that is R.C.C. grid for that structure. At that time various aspects are considered like how the building will be used, what will be the load that various area of the structure will carry, how the soil and environment is where the building will be standing, financial limitations, Govt. regulations, local constrains etc. In all this mental churning there is no provision for the heavy MS Grills hanging on the sides of the building.

With this new insight, once again look at your building and imagine how much that extra collective load your building is bearing on its sides. Think that you have gone to the market to buy your monthly grocery. You have done lot of purchases, so much so that two bags in your hand are weighing 20kg. each. How long you will walk with this load in your hand? You have option to keep the bags on the floor, when you are tired. What happens of a building when it stands like this with extra load mounted on its sides, in all seasons, for years together and when it experiences fatigue?

Building develops cracks. When it can no longer sustain with the load, the weaker areas give way first. There are construction joints in a structure, they start falling apart. This development is progressive and do not halt with normal measures. A portion of a building actually starts tilting and pulling away from the main structure. The cracks and voids which open cannot be permanently sealed. Water enters into the structure through these spots and travel from inside to appear from the weaker spots, located anywhere in the structure.

The grills are fixed by hammering heavy duty nails (plumber’s nails) in to the wall. The impact damages the wall. Wherever the nail is inserted, it starts corroding after some time. The corrosion damages building material around it and creates a cavity at that place. Sometimes this corrosion is even transported to the steel reinforcement of a main R.C.C. grid.

All this eventually weakens the whole structure and slowly makes it unstable.

Grills block the emergency exit

In the hue and cry for safety everybody seems to have forgotten of the emergency exit. Incase of unfortunate fire in the building windows and balconies are used as emergency exits. The fire fighters carry out their operations from the external sides and they use windows and balconies as the entry points. By installing heavy grills in these areas we block their way, no our way to the safety.

Obvious question is then what is to be done?

It is possible to attend to all the concerns of people at the design level and by consultation of people from various fields. A unique treatment to the elevation and with the help of external assistance like CCTV, security gadgets, lighting etc. the problems can be minimized and the ugly appearance can be removed.

In case of existing buildings following things may be adopted –

A. Reduce the weight of the grill by proper selection of material and design.

By this I mean instead of using solid bars use hollow seam pipes of lighter weight which will serve the purpose. Alternatively grill made out of aluminum can also be used. Select such design which is not dense so that less material will be consumed.

B. Limit the grill to the wall surface and do not extend it any further.

There should be no provision for dumping or storing any material including flower pots in to the grill.

C. Incorporate design with hinged emergency doors.

Such doors will be useful when need arises.

D. Take care to seal the nail heads.

Special materials are available which are compatible with building material and metal, so that they do not open due to the thermal variations.

E. Make use of modern safety gadgets and employ professional security guards. It is worthwhile paying little more to the trained and reliable watchman than installing heavy grill.

With such considerations it is possible to reduce the menace created by the grill. Our gesture will also do little bit to face lift our city by bringing down the ugly feature to its minimum.

The Root Penetration a detrimental process

We expect that the building we use should render its services for long long time, rather to the infinity. But every thing on this planet is designated with certain span for existence. So is our building, without any exception.

Since the time of construction of a building, it is provided with inbuilt programs for its deterioration, by the nature. Root penetration is one of them. A small seed which looks insignificant grows as a parasite on the surface of a structure, in to a colossal tree and threatens its own existence. In natural environment it breaks mighty rocks into pieces, building is just a man made structure. Strongest of a building stands helpless against this every day growing monster.

It begins with sprouting of a seed which is dropped by the birds. Most common species of these are Banyan and Pipal tree. However many times even grass or some types of shrubs are found growing on the roof top. The seeds of these plant species are blown by wind and they take shelter on the roof top and gradually make their way into the suitable growing space in a structure.

Most of the building material is lime base. Where there are leakages, ph of the material drop to 6/7. When this is supported by perennial source of water it is the ideal condition for the seeds to germinate and to grow into a tree. These growths normally take place at the junctions of pipe, near leaking sanitary pipes, in the gaps and corners, on the terrace behind drinking water pipe line, etc. and within no time, like a huge octopus, the growing tree spread its tentacles in all directions in to the structure. The roots of these simple looking plants are very strong and powerful. During their growth they make constant efforts to break all the barriers and to reach to their food source. In case this growth is near a construction joint then their penetration becomes very easy and they move into the RCC members (columns, beams, slab) in a grid. At such a growth, bacteria thrive along the roots.

The two are complementary to each other. The bacteria have secretions which are acidic. These acids react with building material and dissolve lime and provide required food enzymes to the growing tree. The process forms small pores to make the surface hygroscopic and absorbent. With every passing season lots of water is absorbed and stored in these pores. It goes on for years to gather to form hairline cracks, big cracks then fissures to weaken the building. All this forms into a cycle which deteriorates the building and keeps destruction program on the progress. Eventually the whole R.C.C. skeleton becomes unstable and culminates in to the collapse of a structure.

The unwanted growth should be removed from its place when it just appears and is barely visible. At the later stage it becomes very difficult to uproot it. It becomes imperative to break down the surrounding portion of the structure to remove the roots completely.

Now day’s efforts are being made to create gardens on the terrace or special flower beds are constructed along the elevation of a building. At such a place mere coating is not sufficient to stop ingress of water into the structure. It should be a multidimensional treatment to have the effective waterproofing and to also grow the garden. The following points should be considered while designing such a garden –

1. Care should be taken at the design level to see that the excess water flows into the drainage system without running hay way and penetrating into the structure.

2. The waterproofing method and the material used should be such, which will withstand against the force and the penetration characteristic of a plant root system. Here coatings are not that effective and get punctured easily. An efficient membrane system can be of some use in such areas.

3. The plant growing program should incorporate highly efficient drip irrigation system which will monitor and provide only that much quantity of water which is required by the plant for its growth, and not more.

When such care is taken, one can grow a flower garden or a kitchen garden, even around his penthouse on the top of a tower building, without having a single drop of water leaking into the structure.

The root penetration is a serious subject in preventing water leakages and it requires due attention if leakages are to be stopped and the life of a structure to be increased.