The problem is that you already have a shingle roof installed and you’re about to install a metal roof on top of it. This adds some significant weight for your decking and home to hold. And if your decking’s integrity is compromised, this extra weight can do structural damage to your roof and even your home.
Is it better to remove shingles before installing metal roof?
Your local roofing contractor may recommend tearing off your old shingles before installing a metal roof if any of the following conditions apply: Rough or uneven asphalt shingle roof will affect the metal roof’s appearance. The deck sheathing show signs of rot and would require repairs.
Is it common to put a metal roof over shingles?
In almost every case, the answer is yes, you can lay down a new metal roof over an existing shingle roof. This is one of the many reasons metal roofs keep growing in popularity ‚Äì their installation doesn’t require completely tearing off the existing roof, which is a time-consuming and expensive job.
How long does metal roof over shingles last?
Metal roofs offer many benefits, including: Longevity. Metal roofs can last 40-70 years, depending on the material. Traditional asphalt roofing materials have an estimated life expectancy of roughly 12-20 years.
Why not put metal roof over shingles Related Questions
What is the best way to put a metal roof over a shingle roof?
The first is to apply an approved underlayment over the old shingles. This is the fastest way to install but it doesn’t provide the flattest surface for metal roofing installation. The second way is to install 1√ó4 purlins over the shingles. This is more expensive but will also be higher quality.
Which is better a metal roof over shingles?
Metal roofing is far more energy efficient than asphalt shingles. Metal roofing offers homeowner’s significant energy savings through the use of cool roof pigments and above sheathing ventilation. Cool roof pigments are designed to reflect sunlight which lowers the amount of energy absorbed by the roof material.
Can you go over 2 layers of shingles with metal roof?
Many metal roofing systems can be installed over 1-2 layers of existing asphalt shingles, saving time, labor, and landfill costs.
How many layers of shingles can you put metal over?
One to two shingle layers can rest safely and securely under a metal roof. Any more than two layers could reduce the stability of your roof. Many building safety codes will not allow more than two layers, so check your local areas before making an installation.
Is it better to roof over existing shingles?
Adding a second layer of shingles on top of the existing roof would double the weight and cause the roofing structure to wear down a lot faster. Unless you are a hundred percent certain that the roofing structure is capable of handling the weight of a second layer of shingles, do not opt for re-roofing.
What goes underneath a metal roof?
Roof underlayment is typically placed beneath all external roofing materials, and is attached directly to the roof decking or sheathing. Three common types of underlayment for metal roofs include felt, self-adhering membrane, and synthetic sheet.
How do you vent a metal roof over shingles?
To vent the roof, holes are cut in the old roof (Detail 1) above the soffit, which pulls air through the soffit vents underneath. Cool outside air then travels under the shingles to the vented ridge (Detail 2), pulling out moisture and heat.
Can you put metal roof over shingles without furring strips?
It is not recommended to install metal roofing over shingles without furring strips. The thermal expansion and contraction of the metal will rub against the shingle granules and the metal will corrode from the underside. The gaps introduced by furring strips also allow air venting which can reduce moisture.
Do metal roofs rust over time?
With advances in paint systems, finishes, and other technologies, metal roofs will withstand oxidation and rusting for most of its lifetime. However, there can be factors that affect whether or not your roof rusts. If you have plain, bare steel for example, it will rust.
Are metal roofs loud when raining?
This is one of the most frequently asked questions we hear from homeowners interested in metal roofing, so we’ll get right to the point‚Äìno, metal roofs are not loud in the rain.
What color metal roof lasts longest?
Lighter colors – tans, whites, and grays – fade far less than darker, more saturated colors. You can also invest in a protective coating that buffers the roof from mildew, moisture, and sun to combat fading. This important step also decreases the likelihood of rust and peeling to keep your roof looking fresh and new.
What is the best underlayment for metal roof?
30# felt underlayment (or two layers of 15# felt) are recommended for metal roof panels. Felt is an all-over roofing accessory made of a natural (wood cellulose, natural fibers, etc.) or synthetic (polyester or fiberglass) base that is then saturated in asphalt to make it water-resistant.
What type of metal roof lasts the longest?
Considered to be the grandfather of metal roofing, copper roofs have been used for centuries around the world. Copper is an extremely long-lasting metal that in ideal environments, can last well over 200+ years. Copper roofs are 100% recyclable too, making them wonderful green roof options.
Do metal roofs fade?
If you’re purchasing a metal roof or already have, you might be asking yourself: Will my metal roof fade? The answer is yes. Fading on painted metal roofs occurs when substances like water, pollution, and chemicals in the atmosphere and specific environments react with the pigment of the paint.
Can you put a metal roof over 3 layers of shingles?
The answer is you can generally install a metal roof on top of shingles if there are fewer than four layers of shingles on the roof, but the exact standards vary by area. However, that process can lead to a variety of complications and therefore is not recommended.
How many times can you roof over shingles?
As mentioned above, homeowners are legally limited to two layer of roof shingles. Therefore, if you already have two layers, you’ll need a full tear-off. Additionally, if your roof is severely damaged, it likely won’t be able to support the weight of a reroof and will need to be torn off.