Depending on the sealant’s thickness, you can apply it with a paint brush, paint roller, paint sprayer, or hand trowel. Some roof sealants come in tubes that are applied with caulk guns.

If you can paint, you can probably seal your flat roof DIY-style, but even if you have to hire someone, it’s not a terribly expensive job.

Lifestyle Your Place: Elastomeric roof coatings last long, if not a lifetime Originally published September 6, 2011 at 6:49 am Updated September 6, 2011 at 9:01 am ...

A coating of lime wash "can cost as little as 1.5 rupees (£0.017; $0.02) per sq ft to more expensive reflective coatings or membranes", says Ms Jaiswal.