Craze cracking in asphalt shingles

Anyone who has inspected roofs has seen craze cracking. It can happen in as little as six years. What causes it is not a mystery. Here’s a good explanation although it’s inaccurate in saying that mats aren’t saturated. They are. Also contains information about shingle warranties that you can pass along to your clients.



Us inspectors here around KC see a lot of craze cracking. Agents and home owners are clueless as to how this happens, and any documentation that we can provide is very helpful.

There’s some question about whether it qualifies as a defective condition or is just poor quality material. Insurance and roofing companies will not call it defective according to their definition.
A defective condition is one that :

  1. Reduces the ability of the shingles to shed water; and
  2. Shortens the long-term service life of the shingle.

Until cracks propagate through the shingle and become splitting, craze cracking doesn’t reduce the ability of the shingle to shed water.

As to reducing a shingle’s long term service life, if the length of the long-term service life is not determined by the length of the warranty, that’s a difficult question to answer. Again, cracks would have to become splits before the end of the warranty period, an event an inspector can’t forecast except by guessing.

Even if the roof was covered by a warranty, the warranty is often void, either because the home was sold and the warranty didn’t transfer, or because the buyer failed to notify the shingle manufacturer of the transfer in writing within the alotted time period. If the warranty is still in effect, it will only cover a limited portion of the cost to replace the roof, possibly not including labor, or at best only a portion of the labor. It won’t cover removal and disposal costs of the old roof.

Inspectors can truthfully say that craze cracking:
…“is typical of asphalt composition shingles in which the asphalt used is of poor quality and will not last as long as shingles made using good quality asphalt.
As long as craze cracking is limited to the weather-facing surface layers of asphalt, the shingles will continue to protect the home from leakage-induced moisture intrusion. Once cracks develop into through-shingle splits, the roof is more likely to leak.
Determining the future rate at which shingles will deteriorate and fail lies beyond the scope of the General Home Inspection.”

As stated in the article in post #1, the number of warranty claims don’t reflect the number of failed roofs accurately. If you inspect a home with a shingle roof that has craze cracking, it’s a good idea to educate your client about the reality of what they should expect as far as the manufacturer’s or contractors warranty taking care of any future problems caused by this condition.

Thanks Kenton. You always have a good read to share.

OK, old thread, new link. Look here