Yes, there are mountings systems that offer non-penetration of the roofs for your rooftop solar.

Traditionally the use of rooftop solar with penetration of the roof has been in practice for a long time. However, non-penetrating rooftop solar has emerged has it can be installed in roofs that are quite ageing or cannot withstand any alterations made to it. Non-penetrating rooftop can be the solution for an individual/organization as they offer:

  • Allow decommissioning or relocating systems without damage
  • Quicker installation, no specialized training is required
  • Versatile – Can be built around existing rooftop obstacles such as HVAC units and roofs of varying heights

How do they work?

  • In non-penetrating system, a rack support system is installed on top of the membrane without anchoring, sometimes held in place using ballast
  • Ballasted racking systems require no penetrations to be made in the roof membrane, and are held in place by the weight of strategically placed cinder blocks. Penetrating the roof membrane to bolt down a mounting system is very labour intensive, and bypassing this step greatly reduces the overall cost of the install
  • Among the numerous mounting systems available in the market, non-penetrating ballasted systems have worked their way to the top of the list, especially for flat commercial rooftop solar installations, due to their speedy install time and low price

Concerns regarding non-penetrating rooftop

  • Non-penetrating systems are not suitable in high wind areas. Even in moderate wind zones, positive attachment to the building is often required in order to have array tilts in excess of 20°.
  • Any layout changes in the rooftop could require the manufacturer’s approval if the product warranty is to remain valid.
  • Common site restrictions may include maximum allowable roof slope and a maximum building height of 60 feet.

So, non-penetrating rooftop can be achieved with the various mounting options available in the market today but they must be carefully analyzed of their pros and cons before selecting the non-penetrating rooftop technology. Do ask the PV contractor prior to installation about ballasted systems on low-slope roofs and impact of movement, abrasion, drainage, and wind.

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