How much of an overlap does metal roofing need to be?
Most experts recommend having the overhang measure anywhere between about an inch-and-a-half and two inches.
Can you put new metal roofing over old metal roofing?
As long as the original metal roof panels are not deteriorated from environmental conditions, a metal-over-metal retrofit can put virtually any type of metal panel over any type of existing metal panel.
Is a drip edge necessary on a metal roof?
A drip edge is not needed for metal roofing. If you make sure to overhang your metal roofing at least an inch, the drip edge is not necessary at the eaves and rakes.
How do you overlap roof sheets?
It is usual to allow roof sheets to overlap into gutters by about 50 mm. The valleys of sheets should be turned down at lower ends and turned up at upper ends. For maximum weather-tightness, start laying sheets from the end of the building in the lee of the worst-anticipated or prevailing weather.
What is a recover system for metal roofs?
By definition, a recover system means that the existing metal roof remains in place and is simply covered with new metal panels.
Can a roof be recovered over a bar joist?
This approach should not be used to recover existing roofs installed over bar joists, wood decks, or metal decks with rigid insulation. As the name implies, the hat over zee clip method involves attaching a Zee clip through the flat of the panel into the substructure below.
How does a 238t metal-over-metal recover installation work?
The system utilizes tall clips that sit between the ribs of the existing panel and are attached directly to the purlin below. The air space between the two roofs is filled with insulation. Shown below are the steps of a 238T Metal-Over-Metal recover installation.
What is the best way to replace a metal roof?
Historically, when the need for metal r oof replacement occurred, the most common approach was remove and replace. Much as the name implies, this method involves completely removing the original roof and installing new metal panels back onto the original structure.