QA

How To Install Metal Roofing Over Existing Shingles

Can you install metal roofing over shingles?

You’ll be able to save up to 25% in labor costs by not tearing off your old asphalt roof, installing new underlayment, or the fees to dump the old roofing materials. So, yes, you can install a metal roof over your old asphalt roof.

What is the best way to install a metal roof over shingles?

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 1×4 purlins over the shingles. This is more expensive but will also be higher quality.

Can you put metal roof over shingles without furring strips?

One option for installing a metal roof over shingles without furring strips is to use a cross-batten style. A cross-batten technique involves laying down vertical battens first. Next, the battens attach through the roof deck to your rafters. Finally, your horizontal battens are placed.

Do you need to put strapping under metal roofing?

Single wood strapping is better than no strapping, as it creates a wider gap between the existing roof decking and the metal roof, but doesn’t afford enough ventilation to resolve condensation issues. It also does not allow leveling of the roof, which corrects swells and swales on the roof.

What type of underlayment do you use on a metal roof?

The traditional and most common material used for roof underlayment on a steep-slope metal roof is non-perforated, asphalt-impregnated felt underlayment. There are several types of felt underlayment including both organic reinforced and inorganic reinforced.

Should you remove old shingles before installing a metal roof?

Metal roofs can be installed over your existing roof without tearing off shingles, provided local building codes allow it. While shingle removal is the preferred route, tear-off is messy and raises the cost of the job. If trapped between the metal roofing and old roofing, moisture can build up and cause mold and rot.

How much does it cost to put a metal roof over shingles?

You can spend anywhere from $5,000 up to $15,000 to install a metal roof over shingles when added together. This value range is for overlaying metal over existing shingles. Your costs will increase if you have to pay for a tear-off due to damaged shingles or the roofing structure.

Does a metal roof need furring strips?

When installing a metal roof over an existing roof, insulate the spaces between the wood strips with rigid insulation to prevent condensation before installing the roofing. You also need to add furring strips. Twenty-four inches is a common spacing of furring strips for a metal roof.

How do you combine metal roofing with shingles?

Tips for combining roof systems: Choose an analogous color palette to provide visual continuity of the roofline. Look to the supportive, less dominant color in the shingle roof as your inspiration for the color of the metal roof. Consider the use of a “pop” color to break up the visual palette.

Does a metal roof need a vapor barrier?

Metal roofs and buildings require specific insulation and vapor barrier to meet the demands of condensation and breath-ability. Depending on whether your building is sheeted or not, or if you require insulation, we have it all, including the necessary tapes for installation.

Can metal roofing be screwed to OSB?

No, you do not need to screw into solid lumber (joists, stripping,etc.). As you can see, the thinnest material they recommend is 1/2” (7/16”) OSB board at 9” on center up to 24” on center. Be sure to follow their instructions in order to obtain the warranty.

How far should a metal roof overhang?

A typical metal roof overhang may be 2 to 4 inches, or even less. Some slight overhang is recommended, in conjunction with a drip edge flashing, to prevent water from getting under the roofing and onto underlying wood.

What goes under a standing seam metal roof?

Underlayment is usually a felt (15 lb, 30 lb, or synthetic) material used over your decking to provide additional protection. That makes it a crucial component to your metal roof. For your standing seam metal roof, your underlayment will be a self-adhering, high heat ice and water shield.

Do you have to put plywood under metal roof?

As long as the interior of your roof is protected from moisture accumulation, underlayment is not required, though homeowners planning to insulate their house heavily may choose to install plywood to protect their investment.

Can I install a metal roof myself?

While most metal roofing styles can be installed as an advanced DIY project, metal roofing installation is complicated and can vary slightly based on the brand of panels or shingles that you select. We recommend that you install a metal roof with one or two helpers and fall protection equipment designed for roof work.

Can a metal roof go over 3 layers of shingles?

Metal roofing is a more efficient and longer-lasting roofing alternative to asphalt shingles. You can generally install a metal roof on top of shingles as long as there are fewer than four layers of shingles on the roof, but the exact standards vary by area.

Is it a good idea to put new shingles over old shingles?

The answer is yes, you can lay new roof shingles over old ones. You can’t do it with wood or slate, for example, and you should never mix materials, such as laying asphalt shingles over cedar shakes. Also, the old roofing has to be in pretty good condition.