Build it green with clay roof tiles

Architect Manoj Patel says they cut down heat ingress, and can be used as stylish facade for exteriors and interiors. By Nandhini Sundar

The handcrafted clay roof tiles may have been a ubiquitous feature in small towns and villages a few decades ago. Yet, a walk through one of them now will see a near absence of their presence, the clay tiles literally on their way out as a roofing material. Interestingly, this discarded clay roof tile comes with an important quality of being climate responsive where it cuts down the heat ingress, thus serving as a fine source of insulation in hot regions.

Architect Manoj Patel, of Manoj Patel Design Studio from Ahmedabad, stumbled upon this local material while doing his research to come up with sustainable green solutions for buildings. “Use of clay roof tiles is on its way out, leaving this handcrafted material on the brink of extinction, forcing traditional craftsmen to give up this vocation and look for employment elsewhere. The technique of handcrafting these tiles will certainly be lost a generation from now and with it the vernacular construction mode of addressing heat ingress”, states Patel.

When temperatures soar to 45 degrees C in summer, the conventional RCC terrace causes heat ingress, resulting in the interiors requiring greater artificial cooling. Worse, RCC radiates heat just as a glass façade does, causing the urban heat island effect. “When an RCC terrace is layered with clay roof tiles, the heat ingress is substantially reduced and prevents external radiation of heat. Cladding the façade with clay roof tiles similarly prevents exterior walls, especially west facing, from being exposed to direct sunlight. This automatically reduces interior temperatures by several notches even in peak summer besides addressing the heat island effect”, explains Patel.

Bringing in craft

Interestingly, Patel goes one step further and brings craft into the equation besides the green quotient. According to him the clay roof tiles can be broken down and clad on the façade in an aesthetic pattern that is in sync with the sun’s movement as well as the wind pattern. “The patterned cladding brings art to the exterior wall while acting as a shield against the harsh sun.”

The presence of clay roof tiles together on the roof and the façade reduces the internal ambient temperature by 10 to 15 degrees C in peak summer, Patel claims. Incidentally, while this keeps the operational costs of cooling minimal, the installation cost of clay tiles is extremely inexpensive as a sizeable portion can be sourced from damaged, broken tiles that are discarded, “as the tiles in any case need to be broken and used.”

Extending to interiors

Patel does not restrict the use of clay roof tiles to exteriors alone, but extends to interior spaces too where they feature as wall art and also serve as vertical planters in balconies and courtyards. These vertical planter boxes double up as an aesthetic green wall in the semi-open interiors as well as aid to reduce the ambient temperature and increase humidity during the dry summer months.

“This is especially so if the balcony or courtyard faces southwest where the heat is intense. Their presence then significantly drops the temperature, acting as a traditional desert cooler, the dry hot air coming in contact with the water-laden planter boxes, becoming thence moist and cool”, adds Patel. His Ridge residential project uses this technique effectively to reduce the interior temperature.

Patel further points that the clay roof tiles are a much better option compared to common plastic planter boxes used for vertical gardens. “The clay continues to keep the roots cool even during peak summer while the plastic does the reverse.” However, given the weight of the clay tiles, Patel faced a structural problem in their vertical installation. “We finally addressed this by using an appropriate chemical bonding material and by engineering their placement in a manner where the full weight of the boxes did not transfer to the floor but rested more on the wall.”

As for the interior spaces, Patel transformed the clay roof tiles into a piece of art by creating a mural on the wall with broken tiles in one of his office space projects where they serve as an arresting contrast against the wood panelling and granite floor in the meeting room. Similar clay murals feature in a fashion boutique that he designed where the clay tile art vie for attention in the vibrant décor. “The waste broken tiles are sourced free and yet they form a fabulous piece of wall art when used creatively”, explains Patel.

Incidentally, Patel’s crafting is not confined to clay roof tiles alone but extends to other forms of discarded materials too. He avers that a design has to be both climate responsive and economical and this can be achieved by exploring options for recycling, reuse and upcycling of materials. In keeping with this, in the same boutique, Patel uses discarded broken bathroom tiles to create artistic vibrant flooring while waste beer bottles form an attractive wall art, usheringnovelty into the retail space.

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