Can GAF Shingles Be Installed Over Existing Shingles?
Yes, GAF shingles can be installed over existing strip shingles, T-lock shingles, wood shingles, laminated shingles, and other asphalt premium shingles. This can be a cost-effective solution for homeowners looking to upgrade their roofs without a complete tear-off.
What Is Required to Roof Over Existing Shingles?
For a successful installation over an existing roof, several key requirements must be followed:
- Single Existing Roof: There should only be one existing roof in place. Most local codes do not allow roofing over more than one roof layer. If there are already two layers, a complete tear-off is necessary.
- Smooth Surface: The existing roof should provide a smooth surface for the new shingles:
- Remove all loose or protruding nails or fasteners.
- Nail down any loose, curled, or lifted asphalt shingles.
- Split badly curled and/or warped wood shingles and re-nail the individual pieces.
- Replace any missing shingles.
When Should a Complete Tear-Off Occur?
A complete tear-off is necessary when:
- Multiple Roof Layers: There is more than one existing roof layer, as required by local codes.
- Surface Issues: The surface of the old shingles is warped, curled, or so badly weathered that providing a level surface for the new material will be difficult.
- Deck Concerns: There are any concerns about deterioration to the deck itself. If the roof is being re-roofed due to extensive leakage, removing the existing roofing materials allows for inspection of the underlying deck. Any deteriorated decking should be replaced.
Shingles Should Not Be Installed Over
GAF asphalt shingles should not be installed over:
- Wood shakes
- Tile roofs
- Metal roofs
- Asbestos shingles
- Roll roofing
- Low slope membrane roofs
- Insulation (direct application)
- Decks other than wood unless an approved specialty deck
Note: This is not an exhaustive list. For installation over any substrate other than a wood deck or an existing shingle product as described above, please contact GAF for requirements and/or acceptability.
Conclusion
Roofing over existing shingles can be a practical option, but it’s important to ensure the existing roof is in good condition and follows local building codes. Proper preparation and inspection can help ensure a successful and long-lasting roof installation.
For Immediate Service or Consultation
Contact Allied Emergency Services, INC.
Phone: 1-800-792-0212
Email: Info@AlliedEmergencyServices.com
Location: Serving Illinois, Wisconsin, and Indiana with a focus on the greater Chicago area.
If you require immediate assistance or have specific questions, our human support is readily available to help you.
Disclaimer: This article is intended for informational purposes only. For professional advice, consult experts in the field.
