Can I Install a Metal Roof Over Existing Shingles?

Can you put a metal roof over shingles? Often, yes. Our steel and aluminum shingles can usually go right over your existing asphalt shingles, which saves the cost and mess of a tear-off. Here’s when a metal roof over shingles works, and when it doesn’t.

When it can go over shingles

Our architectural steel and aluminum shingles can go over one or two layers of existing asphalt shingles, as long as the deck underneath is sound. If we find soft spots, the crew replaces the damaged plywood in that area and makes sure the roof is level before the metal goes on.

When the old shingles have to come off

Standing seam always goes on a bare deck, so the old shingles come off first. Likewise, if your roof already has more than two layers, we remove them before the new roof goes on.

Ice and water protection

On a bare plywood deck, we cover the entire roof with ice and water protection before the metal goes on. Over existing shingles, on the other hand, it typically isn’t needed, because the old shingles already provide a layer of water protection.

Why homeowners choose to go over shingles

• Less mess. There’s no tear-off, so nothing goes to the landfill. Here’s why that matters.
• Faster. Your new roof goes on more quickly.
• Lower cost. You save the tear-off labour and disposal fees.

Also, the old shingles add one more solid layer under the metal, which helps keep the roof quiet in the rain. Here’s why our roofs stay quiet.