HOW TO BUY CEMENT

There are two types of cement: Grey cement - used only for construction purposes, and White cement - for a variety of uses like mosaic flooring, in cement paints, and as a primer for paints, etc. Grey cement costs more than white cement because the production costs and excise duty are higher. White cement also sets faster. For grey cement, the strength after 28 days of setting is taken as the final strength. White cement achieves this strength in about three days time.

The cement has to be fine in texture. It should be smooth, dry and cool to touch. Fineness gives more strength to cement because the chemical reactions take place faster. Do not buy cement which is in rough, granular lumps. This indicates it has been exposed to moisture. Cement is now available in grades and is easier to buy . For eg: 53 grade cement implies that a cube of cement can withstand a pressure of 530 kgs per square centimetre. You can check this on a compressing machine. This is called the breaking strength of cement. Good cement hardens faster. You can therefore remove the scaffolding / formwork sooner than usual. You save on centering and labour costs, and your building is ready much faster.

HOW TO BUY MARBLE

Marble has qualities and advantages over other stone materials. It is more durable, attractive and is available in various colours - white, yellow, red, black and green, which can be used to match any kind of decor.

When used for flooring, it provides a highly elegant finish which is hard, durable, dust free and suits Indian climatic conditions.
Marble possesses great reflective qualities and its crystalline structure gives it a bright lustre. Marble is broadly classified into two categories - white and coloured. For exterior finishes, sound marble with uniform quality should be used. If the marble contains flaws, voids, is discoloured by veins and lines, it should be treated for soundness by spraying surface treatment compounds.

Good marble should comply with the following requirements:

1.If immersed in cold water for 24 hours the marble should not gain more than 0.4% in weight.

2.On Moh's scale (a scale of 1 to 10 to measure hardness of solid materials, where talc, the softest material occupies No.1 position, and diamond, the hardest material is No.10), hardness of marble should measure more than 3.

3.When you buy marble slabs and tiles see that they are square edged. Tiles and slabs are available in the following finishes:
Sand abrasive finish - a flat non-reflective surface.
Hone finish: a velvet smooth finish with little or no gloss.
Polished finish: a highly glossy finished surface which brings out the full colour and character of marble .

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