So, what is roof hugger?
Roof hugger is a product that is used during a metal roofing process called a metal-over-metal retrofit. A metal-over-metal retrofit is when a roofing contractor recovers the existing metal roof with another metal roof without removeing the exist metal. Roof hugger is a metal piece that is installed on top of the existing roof giving a new flat surface to install new metal roofing on.
Roof hugger is basically a hat channel that is made in the shape of the existing roof ribs. Thats how it is installed over the existing metal and is able to sit flat. The notches are designed and fabricated around the existing metal profile.
Roof hugger comes in many sizes and heights to accommodate all types of existing metal roofing. It is made of 16 gauge grade 55 steel and usually comes in 10' 2" lengths. It is generally shipped on pallets so that it is easy to hoist onto the roof.
How is roof hugger installed?
To begin, it is installed directly overtop of the existing purlings and is secured to the purling using a self-tapping screw. After a 10' piece of hugger is installed, another section of hugger is lined up and installed with a 2" overlap.
After that, the overlap is secured with 4 smaller self taping screws. Once completed, each purling on the building should be properly covered with roof hugger. This creates a flat surface for the new meta roofing to be installed onto.
What about all that added weight?
A metal-over-metal retrofit using roof hugger will only add about 1 pound per square ft. of weight to a building. In fact, the roof hugger actually strengthens the existing purlings, greatly increasing the load carrying capacity of the structure. So in short, not only does roof hugger allow you to install a metal roof on top of your existing roof, it strengthens your building's overall structure!