Roofing Options for Asphalt Shingles
Adding a 2nd Layer of Shingles vs. Full Roof Replacement: Which is Best?
When it comes time to replace or repair an old or disrepaired asphalt shingle roof, property owners have some roofing options. A full roofing system replacement is always ideal, but some consider a cheaper solution: adding a 2nd layer of asphalt shingles.
An Asphalt Shingle roof is an entire system of barriers that work together to prevent water, weather, elements, and energy from entering and in some cases escaping the home. Because the roof is subject to constant attacks from weather and is so exposed to the elements it is important to keep your roof in good repair. This article will discuss your options for roofing work if your roof is old, damaged or otherwise in disrepair.
This article from the roofing experts at Superior Services of PA & MD will help property owners decide which roofing option is best for them:
Our extensive experience with roofing insurance claims gives us a lot of insight into this topic and it is our position that adding a second layer of asphalt shingles is an unprofessional practice for a number of reasons. We'll present all these reasons in our article below. Enjoy!
When Roofing Options like Adding a 2nd Layer are Available
Building code regulations allow for up to two (2) layers of asphalt shingles (per 2018 IBC: Chapter 15 Roof Assemblies and Rooftop Structures, Section 1511.3 "Roof Replacement") unless:
- there are already two or more applications of any type of roof covering;
- there is slate, clay, cement or asbestos tiles, or
- the existing layer of asphalt shingles is water-soaked or deteriorated such that it is not an adequate base for existing roofing.
Every roof ought to be inspected individually to determine whether it is even eligible for any roofing options other than a full replacement. Even when a roof is technically eligible, most experts will tell you that re-covering (overlay) is an unprofessional practice that makes for an inferior roof, and that is our position here at Superior Services of PA & MD. Other roofers may tell you that asphalt shingle overlays are an affordable option for fixing an old roof, but we have yet to find a roofer who recommends it outright.
PA & MD Roof Replacement Services
Superior Services, with help from our sister company Chateau Public Adjusters, provides a unique service to property owners in Hanover PA and Carroll County MD in need of roof replacements, repairs and storm damage restorations. It starts with a free roof inspection! Get yours today...
Why Adding a 2nd Layer is NOT the Best Roofing Option
Roofs are a System, not just a Layer of Shingles
A roof works to protect a home by keeping the elements out and energy in, and it is a system of barriers - from flashing and weatherproofing to the wooden roof deck up to the outermost barrier: in this case, the asphalt shingles. When you add a second layer of shingles there is no way to tell the condition of the other components of the roofing system such as the roof deck, underlayment, flashing, etc. This is why insurance companies often pay for the complete tear-off of both layers (more on that in the next section below). Also, the first layer of roofing shingles can become overheated underneath the outter layer.
Adding a 2nd Layer Voids the Roof's Manufacturer Warranty
The practice of re-covering with a second layer of shingles, even when doing so complies with building codes, always results in a void of the manufacturer warranty on not only that overlaid second layer of roofing shingles but the original layer also, which means there is no guarantee that your roof will last. With GAF's lifetime guarantee (35 Years) on their Timberline HD roofing systems, it is entirely wasteful to get a new roof with no warranty. A roofing system installation (see details below) consists of several roofing components, including flashing, drip-edge, underlayment and snow and ice shield in the valleys of the roof. These components cannot be installed without tearing off the existing asphalt shingles.
How Insurance Companies Handle Roofing Options for Asphalt Shingle Roofs
If your homeowners insurance policy has code enforcement coverage then your insurance company must almost always pay for complete replacement of your asphalt shingle roof with more than one layer. The reason for this is that we need to get down to the roof deck to discover rotten, deteriorated or delaminated sheathing and in order to do that we need to remove both layers of asphalt shingles. At Superior Services of PA & MD it's been our experience that the great majority of customers with 2 layers of asphalt shingles end up easily securing full approval for a complete replacement, including a brand new Lifetime GAF roofing system.