Are Your Shingles Bonded? Even New Roofs Often Have This Defect

For most of my clients the roof is one of their biggest concerns.  As one of the most expensive components of the home, it’s important to know the condition of the roof before buying a house.  Many homes advertise new or newer roofs, but that doesn’t guarantee they will be free of defects.  One of the most common problems I find when I inspect roofs is poorly bonded shingles.  This can be a big problem if left as-is, but there’s good news for buyers that find this condition ahead of time.

First lets talk about what bonding is and how poorly bonded shingles are a problem.  Asphalt shingles are manufactured with adhesive asphalt strips located beneath tabs that are designed to soften in the heat of the sun and bond overlapping shingles together. The desired result is that the entire shingle roof acts a single, unified membrane. Properly bonded shingles cannot be lifted as shown above.  Successful bonding of the shingles is the most important factor in determining the shingle roof’s resistance to wind damage.  When wind can get underneath improperly bonded shingles, they can be ripped right off the roof.  This will affect the roof’s ability to shed water and could result in leaks.

A weak bond can be caused by different factors:

• Poor quality shingles can have inadequate or poor-quality adhesive strip materials (for which there are no
  manufacturing standards).
• High winds blowing at the time of installation can contaminate the adhesive strips with dust and dirt.
• Since adhesive strips are activated by heat, shingles installed during the winter may take months to bond
  fully.

So do poorly bonded shingles mean you need a new roof?  Thankfully no.  The good news with poorly bonded shingles is that they can be hand sealed if they are found on time.  This can be done at a much lower cost than repairing shingles that have torn or blown away, and hand sealing is significantly less expensive than roof replacement.  All roofs new and old can have poorly bonded shingles, and many roofs with poor bonding can look perfectly good the untrained eye, so it’s important to hire an experienced inspector to find this problem before it becomes serious.