NEW PROVEN LOW RISK FM-APPROVED SYSTEM

FM4478 - Roof mounted rigid solar module systems

The FM4478 standard is one of the few serious approaches to ensuring realistic, safe and durable solar installations on roofs. As a supplier of roofing accessories to the flat roof market for decades, we have never come across such a demanding standard. It illustrates FM Approvals' uncompromising approach to minimizing risk in the construction industry to protect building owners from natural disasters and fire.

In this article, we provide an in-depth insight into the extensive testing of our JUAL PV-X mounting system for rooftop solar panels with single-ply membranes. The focus will be on wind uplift and fire tests - the most extreme tests in the FM4478 test scheme.

A breath of fresh air for the industry

It is important to understand that FM4478 is firmly rooted as a "roofing system" based on the FM4470 standard for approval of roofing and associated roof structures.

For JUAL, which has followed the rooftop solar industry for many years, the FM4478 standard is a much-needed breath of fresh air for both the construction and solar industries, which have operated independently of each other for far too long.

FM4478 considers solar installations as part of the building - both structurally and in terms of water tightness. Important criteria from both industries are integrated into realistic solutions that unite solar and roof structure in a technically balanced system.

About the test

The PV-X system consists of roof anchor points with brackets and FM4478 approved solar panels. The test series includes hail, gravity (snow), water tightness, fire and wind uplift.

While all elements of the FM4478 test series are essential for a durable installation, in this article we focus on wind lift and fire testing, which we believe are the most risky and often overlooked elements.

The right solution for the building

The JUAL PV-X system is a roof-parallel, fully structurally anchored system that requires anchoring into the building structure with corresponding penetration of the roofing. Often roof and PV suppliers work independently and are not very coordinated in their approach to flat roof PV systems.

The number of FM4478 approved systems in FM's RoofNav database clearly underlines this. At JUAL, our ambition has always been to offer the right solution for the building - even if it has required bridging two industries that do not normally work closely together.