When it comes to renovating or installing a new roof, homeowners are often faced with various options and considerations. One commonly asked question is whether it is possible to install metal roofing over existing asphalt shingles. The answer is yes, it is possible to install metal roofing over asphalt shingles, but there are some important factors to consider before making this decision.
Benefits of Metal Roofing
Before delving into the details of installing metal roofing over asphalt shingles, it is important to highlight some of the benefits of metal roofing. Metal roofs are known for their durability and longevity. They can easily last up to 50 years or more with proper maintenance. Additionally, they are fire-resistant, energy-efficient, and environmentally friendly, as they can be recycled at the end of their life span. Metal roofs also provide excellent protection against heavy rain, snow, and extreme weather conditions.
Considerations before Installing Metal Roofing over Asphalt Shingles
1. Local Building Codes and Permits
Before proceeding with any roofing project, it is crucial to check your local building codes and obtain any necessary permits. Some areas may have specific regulations regarding the installation of metal roofing over existing shingles. Compliance with these codes is essential for both safety and legal reasons.
2. Roof Structure and Condition
Another important consideration is the condition of your roof structure. Metal roofs are significantly heavier than asphalt shingles, so it is vital to confirm that your existing roof structure is strong enough to support the additional weight. An inspection by a professional roofing contractor will help determine if any reinforcements or adjustments are needed.
Additionally, the existing asphalt shingles should be examined for any signs of damage or decay. If the shingles are in poor condition, it is advisable to remove them before installing the metal roof to ensure a solid foundation.
3. Roofing Material Compatibility
Certain types of metal roofing are not compatible with asphalt shingles. For instance, standing seam metal roofs require a smooth surface to be properly installed, which means the asphalt shingles need to be removed. On the other hand, metal roofing panels or tiles can often be installed over existing shingles without any issues.
Installation Process
If you have determined that installing metal roofing over asphalt shingles is feasible, here are the general steps to complete the installation:
1. Preparation
First, the roof needs to be thoroughly cleaned and cleared of any debris. This ensures a clean working surface and prevents any interference during installation. The existing shingles should also be examined for any protruding nails or loose boards that may need to be fixed before installing the metal roof.
2. Installation of Underlayment and Metal Roofing
Next, a suitable underlayment should be installed over the existing shingles before placing the metal roofing panels or tiles. This underlayment acts as an additional moisture barrier and provides added insulation. The metal roofing is then installed according to the manufacturer’s instructions, ensuring proper fastening and alignment.
3. Flashing and Sealing
Proper flashing is essential to ensure a watertight seal around roof penetrations, such as chimneys, vents, and skylights. Careful attention should be given to these areas to prevent potential leaks. Additionally, all seams, joints, and fasteners should be adequately sealed to provide maximum protection against water infiltration.
It is possible to install metal roofing over existing asphalt shingles. However, it is crucial to consider factors such as local building codes, the condition of your roof structure, and the compatibility of the roofing materials. Consulting with a professional roofing contractor is highly recommended to assess the feasibility of installing metal roofing over asphalt shingles in your specific situation. By following the appropriate steps and ensuring proper installation, you can enjoy the numerous benefits of a durable and long-lasting metal roof.