Yes, it is possible to install metal roofing over shingles without the use of furring strips. However, this doesn’t necessarily mean it’s the best approach. The decision depends on several factors including local building codes, the condition of the existing roof, and potential long-term ramifications.
Metal Roofing Without Furring Strips
Installing a metal roof without furring strips involves attaching the metal roof directly to the existing shingle roof. This can be a quicker and cheaper solution because it eliminates the cost of materials and labor associated with furring strips.
However, there are a number of potential downsides to this approach. The lack of a ventilation gap can lead to increased heat transfer into the home, making it less energy efficient, and may cause condensation issues that can eventually lead to wood rot and mold growth. In addition, any irregularities in the shingle roof surface can potentially cause deformation in the metal roofing, known as “telegraphing,” which may affect the roof’s aesthetic appeal and functionality.
Considering Local Building Codes
Before deciding on your installation method, it’s crucial to consult your local building codes. Some regions have strict guidelines concerning the number of roofing layers a house can have. While some allow for multiple layers, others mandate the removal of all existing roofing materials before a new roof can be installed.
Evaluating Your Existing Roof
If your existing shingle roof is in poor condition, with curling or broken shingles or areas of sagging, it is advisable to strip it completely before installing the metal roof. In these cases, the use of furring strips won’t be enough to create a solid foundation for your metal roof. Ignoring the condition of the existing roof can lead to major problems down the line, including structural damage that may be expensive to rectify.
Long-term Considerations
While you might save some money upfront by avoiding the cost of furring strips or a full roof removal, there can be potential long-term costs associated with skipping these steps. Issues like the reduced lifespan of the metal roof due to moisture damage, potential violation of the roof’s warranty terms, or decreased energy efficiency can add up to significant costs in the future.