Getting the right finish
Masons are slowly forgetting the ‘how’ of laying a red oxide floor as no code of practice is being followed.
How we cook decides what food we get; our singing leads to the song we hear; irregular training will not produce champions of sports. The lesson from all these examples is simple — the process has much to do with the final product we get.
Strangely, the construction industry is slowly forgetting or knowingly ignoring this lesson. Most complaints about bad quality work could simply be a result of not following the prescribed procedure and may not be related to men, money or material.
Red oxide floor is among the items of construction ill fated due to the above cause of not following a code of practice. Though the recent times has seen a revival of this technology, the present generation is slowly forgetting the “how” of red oxide. Every other mason and builder has executed it in their own way, often leading to not so good finish and slowly the flooring technology itself has got a bad name today.
Among the present contractors, Vijaya Shankar has gained considerable experience in red oxide floor work.
He follows the traditional method, slightly improvised to avoid the known pit-falls. First, the base layer, about 2 inches thick, needs to be laid with 1 part cement, 3 part sand, and 6 part stone aggregate of 12 mm thickness.
Plain glass cut to 2 inch width should be embedded within this concrete layer, at average 5 ft. distance or to subdivide the floor area equally.
The top of these glass pieces should be at perfect level verified by tube levels and the top cut edge of glass needs to be neatly done.
These glass divisions ensure the floor is one level, an important criteria, and stop the minor shrinkage cracks from spreading out, another equally important criteria.
A fine mix of 1 part cement and 4 parts of clean sand should be spread on the concrete screed layer with a trowel, popularly called karni , to fill the small gaps.
Upon this consolidated layer, a thin slurry of red oxide powder and cement mix should be placed and pressed gently to densify the surface. Some water may rise to the surface during this stage. If this application is well done, the final finished surface will gain good red colour without white patches.
Once the thinner slurry settles within the base layer, thicker slurry of 1 part of red oxide, and 3 or 4 parts of grey cement would be applied with a gurmal , the square trowel with top handle. The mason would walk backwards applying the mix, while the surface would slowly get dried.
After waiting for up to one hour, following the early setting, the surface is finished with repeated swinging movement of the trowel ensuring no trowel marks show up.
This trowel application should go on continuously till the floor gets fully dry, until no water condenses on top or seeps up. The foregone description amply proves that red oxide floor is really a hand-made product!