Metal over Modified/ Single-Ply Recover
The life expectancy of a properly drained standing seam metal roof with no exposed fasteners is 30 to 50 years. This is much longer than the modified/ single-ply systems typically used on low slope commercial applications. Metal is rarely used on a low slope, but can significantly out perform these other systems if proper care is taken in choosing the right system.
The basic requirements to recover a modified/ single-ply roof using the 238T are a minimum 1/4” sloped deck below the existing roof that will hold fasteners, and replacement of any wet insulation. By using our Transverse Panel Curb detail, in many cases the existing curbs do not have to be modified. The 238T system as installed allows for a 3/8” air space between the new and old roof. This air space can significantly reduce the radiant heat transfer into the building.
Externally Drained
Recovering an existing modified/single-ply roof that drains into a gutter using the 238T System can provide an economical, long lasting alternative to traditional re-roofing options. Like a Metal over Metal generated. In most cases, the existing penetration curbs can be utilized without modification using our Transverse Panel System (see photo above). Various panel widths and Transverse Panels are applied in a manner that prevents water from ever reaching the back of the curb. The end result is improved weather-tightness and lengthened life expectancy for your roof system.
Internally Drained (238T-ID)
This is an area where no one uses metal. Our question is why not a metal hybrid roof? Leave the roof in place, install 238T-ID directly to the existing deck using patented 6” offset clip and support system with R-19 6” batt insulation between the two roofs. The water runs off the metal roof into a high end single ply trough that feeds scuppers or internal drains. This results in a roof that is almost 100% metal – creating a 40 year roof solution for 95% of the roof, leaving only a 5% maintenance area.
