In virtually every scenario, the answer is yes; a new metal roof may be installed over an old shingle roof. One of the many reasons metal roofs are becoming more popular is that their installation does not necessitate entirely taking off the previous roof, which is a time-consuming and costly task.
Metal, while extremely robust, is extremely light, weighing less than a pound per square foot compared to up to four pounds per square foot for asphalt shingles. The addition of a metal roof over existing shingles does not considerably increase the total weight on the housing structure.
Installing a new metal roof over an existing roof not only saves the cost of entirely replacing the present roof, but it also provides the benefit of more insulation above your home to keep heat and cool from escaping.
Since we’re talking about insulation, we should emphasize that metal roofs are heat-blockers, meaning they reflect heat away from their surfaces rather than absorbing it. This implies that the additional insulation from your shingle roof will not operate as a heat trap for heat emitted by your metal roof.
Considerations for putting a metal roof over shingles
- In most situations, what we suggested about placing metal over shingles is correct. However, it’s always a good idea to check with your local building and zoning agencies to ensure that metal-over-shingle installations are permitted.
- If your shingle roof is leaking, look for rotten rafters or sheets. These issues should be addressed prior to the installation of the new roof.
- If the present roof’s weight has produced structural difficulties such as buckled trusses or drooping decking, these issues must be rectified before new installation can begin.
- It’s typically a good idea to install some form of underlayment on top of the tiles to keep the granules from contacting the metal and causing corrosion. Your metal roofing contractor will inform you of your alternatives in this regard.
The Advantages of Sturdy Metal Roofs
When you put a new metal roof over an existing shingle roof, you instantly save money that would otherwise be spent having the old roof removed. However, this is only one of the numerous advantages of a metal roof. Here are four more examples:
- Longevity: A properly fitted metal roof should endure for 40 to 50 years or more before it has to be replaced.
- Virtually impenetrable to damage: Metal roofs withstand the most severe weather occurrences, such as hail and ice storms, as well as gale-force winds and blistering summer heat.
- Low maintenance: Because of their robustness, metal roofs do not require frequent, costly repairs. They remain sound year after year, decade after decade.
- Lower cooling costs: As previously mentioned, unique coatings on metal roofs allow them to reflect and repel heat rather than absorb it. This results in cooler interior temperatures throughout the summer and less demand for your air conditioning system.