One noticeable aspect of this pergola is its Topgal polycarbonate cover. It shields the covered area from rainfall, so our clients can enjoy their patio “rain or shine.” While it may look like a simple sheet of plastic, this cover is a four-wall structure that provides thermal insulation. The pergola cover allows light to pass through but blocks UV rays to reduce solar heat gain below. It’s an excellent weatherproofing feature with an unobtrusive appearance.