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.