Should I tear off my existing shingle roof or should I install another layer of shingles over it?

This is a question that comes up very often when homeowners are trying to decide which is the most economical way to have a roof replaced.  Obviously the most economical way to have a new roof installed is to re-roof  over the existing shingles.

• The disposal costs of  a re-roof are minimal.
• The labor cost to remove the existing shingles is eliminated.
• Underlayment costs may be eliminated.  This will reduce material costs.
• The cost associated  with protection of the home during a  re-roof  are greatly reduced.  This eliminates  the cost to have tarps available, plywood for protection of siding, windows, doors and landscaping, etc.
• The labor cost to remove and replace areas flashings may be eliminated or greatly reduced.

How much money can I expect to save by re-roofing instead of replacing my shingle roof?

Generally you can expect to save 30 to 50% off of the price of a tear off.

Will the shingles on a re-roof last as long as a roof replacement?

No, generally you can expect up to a 30% decline in the life expectancy of shingles installed over existing shingles versus installed onto a roof deck. This will be especially true in warmer climates.

Can I get the same warranty on shingles installed over existing shingles as the warranty provided for shingles installed onto a roof deck?

Yes , the warranty is on the shingle  regardless  of a re-roof  or tear-off.

What will help determine whether my shingle roof is a good candidate for a re-roof?

• Only one layer of shingles are now on the roof.
• There are no issues with roof leaks.
• The roof shingles appear to be relatively flat.
• There are no issues with ice damning.

Local building codes and ordinances do not prohibit re-roofing.   However, most codes generally prohibit the installation of  more than  two layers  of shingles.