All buildings require periodic maintenance, more so during the rainy season. Damage caused by monsoon, wind and rain, needs to be repaired. Due to the action of weather over a period of time, most building materials show signs of ageing.

Roof

The portion of the house that receives the maximum beating from the weather is the roof. This is the most exposed part of the house and needs our special attention.

Repeated cycles of heating and cooling along with getting lashed by the winds and rains causes many materials to crack and deteriorate fast. This is especially more if the materials used for weather proofing are substandard or were the wrong choice.

For centuries, building roofs were weather proofed with lime and brick bat concrete known locally as ‘Surki’. But for the past 10 years or so, due to high levels of atmospheric pollution, there is increased level of acidity in the rain. Due to this, the lime based mix is rapidly deteriorating and needs to be protected with a new layer of acid resistant weather proofing material.

As a temporary measure however, any depression found to be accumulating water on the weather proofing surface needs to be immediately taken care of. Even a simple mix of cement mortar with waterproofing compound can be applied to last for a season or two.

Clay tiles

Of all materials, inert material like clay tiles, specially made for weather proofing is ideal. Other choices are natural stones like Shahabad stones, but these are heavier than clay tiles and don’t insulate the roof against heat and cold as much as the clay tile does.

Even though the tiles themselves last for many decades, the joints filled with cement slurry are not so stable and give away much faster. With constant expansion and contraction of the roof surface due to temperature changes, the joints become weak and cracks gets formed.

Unless we take care of these cracks, they have a tendency to widen and then water can enter through these and cause dampness. If these cracks are left unattended, they may even cause water leaks inside the house.

If cracks are visible on the tile surface, then just brushing in of cement slurry mixed with water proofing compound is sufficient. If the joints have completely come off, then they can be refilled with a thicker mix of cement and water proofing compound.

Weather proofing

Similarly any loose tile that has got separated either due to bad workmanship or weathering can be refixed. This is the advantage of tiles as weather proofing material. The repairs can be done where it is needed without disturbing the other tiles.

The repairs are easier since the tiles get fixed individually. Whereas in a monolithic layer, the repairs are difficult. If we try to repair at one place as in ‘piecemeal’ fashion, the new mortar does not join well with the older monolithic layer of concrete and fresh cracks may appear defeating the very purpose of repair.

Leaves and other flying wastes tend to accumulate on the roof. When it rains, these flow towards the ‘rain water down-take pipes’ and block them. Stagnant water on the roof is a serious situation. Unless the water is made to flow freely by removing the blockage, water is sure to seep in. Roofs are meant to be weather proof and not exactly water proof. When it rains, the water should flow outward.

Weather proofing is not meant to take care of stagnant water on the roof.  Stagnant water, especially near the pipe outlets, is likely to rapidly percolate down the roof as the weather proofing layer here will be the thinnest as it is the lowest ‘valley’ part. The ridge areas are comparatively less troublesome, as the weather proofing is thicker here. Tiles on roof surface are laid in ridge and valley pattern to allow drainage of rain water towards the down take pipes.

With a bit of care, we can have trouble free service from the most important part of any shelter - ‘The roof over one’s head’’.

The author is an architect and can be contacted on phone no 9844132826 or Email architectjayaram@yahoo.com