Could you suggest a treatment for Italian marble when used as wall cladding in a bathroom?
Most foreign marbles come pre-treated with hardeners and surface sealers to stabilize their often fragile structure against normal physical handling. Although these treatments reduce the permeability of stone and improve its functional life, I recommend you supplement it with specialized surface treatments that increase surface shine and reduce its tendency of developing cracks and of absorbing and retaining stains.
The brand Akemi (www.akemi.com) has some good products that could intensify the natural colour of the stone, give it a wet look or make it moisture- and dust-resistant, along with improving its inherent strength. Here are two options:
Stone strengthener E: When applied on a raw stone surface, this chemical penetrates to 18mm depth and increases its strength. A 1.5kg pack of this colourless strengthener costs Rs2,500 approximately, and covers 100-150 sq. ft.
Stone impregnation: This product contains siloxane, which penetrates deep into the stone to make it waterproof, without affecting its vapour permeability. One litre of it can cover 80-120 sq. ft approximately (depending on porosity), with no discolouration.
For the actual treatment, identify a good local vendor who has used similar products earlier or talk to the company representative to identify a competent service provider. It’s very important to understand the extent of service provided by the vendor and negotiate rates accordingly.
I am renovating a bathroom, which is to have wooden cabinets under the washbasin. As the counter is adjacent to the washing area, what material should I use? For water resistance, is there any economical material that can be used before polishing or any special coating that can be applied over polish?
Over a period of time, water can deform and disfigure most materials, including concrete, steel and even some of the hardest stones. So we accept that most materials will undergo some form of deterioration when in contact with water. Even though it may be no more than simple water stains or discolouration, water does make its presence felt in some way or the other eventually.
Wood in the wet: Bathroom cabinetry and cladding can withstand the inevitable splashes of water with the right treatments.
That said, the simplest material for cabinetry is “water retardant” or “waterproof” wood ply or boards. Technically, it is the adhesive used in the plywood boards that imparts water repellent or resistant quality to the material. Make sure you do not invest in “water resistant” materials, though—they will only “resist” water for a short period of time, and then start to deform or distort. Some vendors import specially treated natural wood planks that are good for outdoor applications. These, however, also develop cracks and flints on extended exposure to moisture, and should be used only if the customer insists on natural wood.
An alternative is “wood fibre-reinforced cement boards” (Everest Industries and Bison Boards are popular brands). They stand up very well to water, but are cumbersome to work with and don’t look good by themselves. Glass and stone are very good alternatives too, but equally hard to work with. Corian is another versatile material that is impervious to water. However, finding a good dealer who delivers on time is very difficult. For all of these, you will need an excellent team of workmen with experience in handling these materials. The most popular option among designers is to make the frame of the entire cabinet (rear body) out of a water-retardant stone, cement board or glass, and make just the front shutters out of waterproof boards. Plan the fixing detail of the shutter to the rear frame carefully. Connecting a hardwood frame (1.5x2 inches) as an interface to the rear frame and fixing the shutter hinges to it improves the workability and maintainability of the system.
Another option is metal cabinetry meant for the kitchen (such as Godrej and other vendors, some available online).
To protect further, laminating the external surfaces helps, as do surface sealers such as melamine or polyurethane (PU) finish over polished or lacquered surfaces. The choice of laminate or stone colour and polish finish have no impact on the material’s ability to restrain water, though. A ballpark evaluation of shutter finish costs, arrayed from lower to higher, would range the treatments thus: paint, laminate, veneer + melamine/PU, modular wood or metal cabinets, Corian or other alternatives.
(Malhotra is a Delhi-based architect.)
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