A green roof is a living roof system that incorporates plants and soil or a growing medium over a waterproof membrane, offering benefits like better insulation, stormwater management, and a pleasing natural look. When considering installing a green roof, one of the key decisions is whether to overlay the existing roof or perform a complete tear-off before installation. Overlay means placing the green roof system directly on top of the current roof without removing the old materials. This can be quicker and less expensive initially, but it adds weight and can trap moisture between layers, potentially causing problems down the line. A tear-off removes the existing roofing materials first, allowing the roofer to inspect and repair any underlying damage and apply proper waterproofing membranes designed specifically for green roof systems. This option is usually better for long-term durability and ensuring warranties remain valid since most manufacturers require clean, dedicated surfaces for green roof installation.
To safely check whether your roof is suitable for an overlay green roof system, you can start by examining the age and condition of your current roofing materials. If the existing roof is nearing its life expectancy, has visible damage, or multiple layers, a tear-off is often the safer route. Look in the attic during the day for any signs of leaks or water stains, which suggest underlying issues that need repair before a green roof can be installed. When you do call a roofing contractor, ask them two important questions: “How many layers of roofing material will you allow underneath the green roof system, and how do you ensure proper waterproofing with an overlay?” Secondly, “Will the installation affect or void my current roofing warranty?” Clear answers to these questions can help you decide the best, safest approach for your green roof based on conditions, weight limitations, and manufacturer guidelines.