Absolute steel advises screws be installed down inside the flat of the panel and not in the top of the rib.
Where should screws be installed in metal roofing.
Corrugated roof panels and other exposed fastener metal roofs are usually held together with screws every 18 inches or 2 feet.
See the illustration below.
These screws must be installed at the proper.
The screw will compress better when attached in the low and you are less likely to distort the metal roofing panel when you tighten the screw.
Quite often the screws are over tightened or under tightened and when this happens it creates leak points.
Today the fasteners of choice for corrugated roofing are gasketed hex head screws with a metal and rubber washer below the head.
These are where to screw down corrugated metal roofing.
This is important as placing a screw in the top of the rib will prohibit a good seal.
Metal roofing installation requires special metal roof screws that are equipped with a metal washer with a neoprene seat on the base of the washer.
Screws that are installed in the low of the metal roofing panel will result in a more secure connection but will be less weather tight.
Your roof will have thousands of screw holes.
As the screws are driven the washer presses against the metal roofing to form a water proof seal.
Be sure the larger edge is laid so that the small edge of the next panel will overlap it.
However you have to ensure the rubber washers have enough space to move around.
Find roofing screws with either manufactured rubber caps or washers that will create a proper seal.
Working with metal siding and roofing will often create gaps when the screws are inserted into the metal.
This will prevent any possibility of rust or erosion.
Install the roofing screws vertically along each rib in the panel.
If placed in the top of the rib the screw may also potentially tilt thus stretching the screw hole.
This can potentially cause damage in the future.
The main cause of a leaking roof on a diy metal roofing installation is incorrectly fastening the screws.