FAQ
At Fabral, we know that many people have questions about how metal roof and wall panel systems work. Architects, builders, and homeowners are accustomed to shingled roofs. Metal, while far more durable, can raise some concerns. Take a look through some of the commonly asked questions below. If your question is not listed here, please contact us and we can answer any question you may have.
- What colors are available?
- What roofing or wall panel is best for me?
- Why does your installation manual show the metal wall panels held so high above the ground?
- Can I install metal panels directly over my old, worn-out shingles?
- How do I attach metal panels?
- Can I add insulation under the metal panels?
- Is metal roofing noisy when it rains?
- How long will a metal roof last?
- Are any special tools required?
- What is the best material to use along the ocean?
- Do I need a rubber membrane underlayment under metal roofing panels?
- Will a metal roof make my house or building more susceptible to a lightning strike?
- Can I use a lead pencil to mark on my metal panels?
If you still need tech support, click here.
Why does your installation manual show the metal wall panels held so high above the ground?
We show the panels held up above the ground level to make sure the bottom of the panels are not in constant contact with moisture, which would accelerate corrosion. To avoid contact with moisture, the panels should not be in constant contact with the ground or vegetation.
Can I install metal panels directly over my old, worn-out shingles?
Since metal weighs only 1/3 as much as shingles, you can often attach metal panels without tearing off your existing shingle roof. This eliminates the cost and problems of disposing of the old shingles. The best way to do this is to attach 1″ x 4″ or 2″ x 4″ furring strips at 24″ o/c parallel to the eave and ridge. Check local codes to determine if tearing off shingles is required in your area. Request Fabral’s Technical Bulletin #721 for additional information.
How do I attach metal panels?
You may use either screws or nails—both color matched to the color of your roof. Screw fasteners are designed to go into the flat part of the panel. Nails MUST GO in the high rib of the panel. Fasteners are typically spaced 24″ o/c. The FabrOseal is the best available option as a nail and also a viable option to fasten the panel if screws are not the method to be used by the installer.
Can I add insulation under the metal panels?
Yes. Among the types of insulation that can be used are fan-fold foam insulation or foil-faced plastic bubble insulation. You can save utility costs by making your roof more energy efficient.
Is metal roofing noisy when it rains?
No more noisier than the soothing patter that you hear now. The metal roof panels are installed over felt paper and plywood on the outside, with a layer of sound-deadening insulation and your drywall ceiling on the inside. These materials help deaden the sound.
How long will a metal roof last?
This could very well by the last roof you will ever put on your home, barn, shed or hobby shop—with life expectancies that can easily exceed 30 years. Corrosion resistant substrates and long-life finishes ensure long-term performance, minimal maintenance and life-cycle cost savings.
Are any special tools required?
Metal roofing and siding can be easily installed using standard hand tools such as a screw gun, hammer, metal snips, caulk gun, pliers, chalk line and tape measure. Cutting metal panels is best accomplished with an electric metal shear; however, panels may be easily cut with a circular saw with a metal-cutting abrasive blade. Standing seam roof systems require hand or mechanical seaming tools available from Fabral. See our installation instructions for complete details.
What is the best material to use along the ocean?
The salt spray from the ocean is very corrosive to most steel panels; therefore, the best solution would be to use a painted aluminum panel in these areas.
Do I need a rubber membrane underlayment under metal roofing panels?
A rubber membrane underlayment is always a good idea as an additional barrier against water infiltration. You should always use one under a valley condition or any other detail that is likely to be difficult to seal. A rubber underlayment is also recommended at the eave and up to at least 24″ past the exterior wall in a northern climate to help prevent water from entering the roof due to ice damming. It should also be used on very low slopes and when the metal panels are not sealed at their side laps.
Will a metal roof make my house or building more susceptible to a lightning strike?
No. A metal roof will not make a building more susceptible to a lightning strike. Lightning will tend to strike the highest object in a given area, regardless of what that object is made of. A metal roof can actually be beneficial in the event of a lightning strike due to being a non-combustible material.
Can I use a lead pencil to mark on my metal panels?
No. Standard lead pencils, or those made with graphite, will accelerate the corrosion of the metal near the mark. You can use masking tape and mark on the tape to prevent corrosion—plus, masking tape is easier to see.


