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  • Jessica Weber

Why You Should Not Have Multiple Layers of Shingles on a Roof

You may wonder, "Who is the best roofer near me?" As experienced and respected Lehigh Valley roofers, we are here to share our knowledge of roofing techniques and technicalities to keep you informed of best practices when it comes to roofing.

Let's consider why adding multiple layers of shingles to a roof is a bad idea.

1. Serious Possibility of Structural Damage to Your Home

Adding a layover means more weight. A complete overlay on the typical 30-square roof results in around 9000 pounds of extra weight bearing down on your roof decking, rafters, and walls. Consequently, your house may suffer damage to its structural integrity and be at an increased risk of leaks that result in rotted wood and mold growth.

Warping of the old shingles also means that the layover of new ones isn't fastened down as securely. As a result, gusts of wind can lift them off your roof, negating the "repair." Increased hot air buildup between the layers often results in premature aging of the new shingles.

Responsible Lehigh Valley roofing contractors will never endanger your home in this way.

2. Greater Risk of Mold and Algae Proliferating

Layover results in your roof getting more humid as moisture accumulates, creating an ideal place for mold and algae to run wild. This quickly destroys your shingles and can also cause your family health problems.

3. Hides Signs of Damage

Putting new shingles over old hides signs of damage such as black mold growth, torn underlayment, rotted decking, and rusted flashing. It also makes detecting the origin of a leak problematic.

Hiding damage with new shingles is highly unethical. If you want to know, "Who is the best roofer near me?" turn to reputable Lehigh Valley roofers who will fix your roof rather than hide its issues.

4. Increased Long-Term Expenses and Diminution of Property Value

The cumulative damage mentioned means you will have to spend a lot more long-term to fix your house. Home inspectors are also required to report layovers, resulting in diminished property value and possibly negating your homeowner insurance.

Warping of the old shingles means the layover doesn't lie flat, diminishing the aesthetics of your house. Maintaining curb appeal is a good idea, even if you aren't planning to put it on the market soon.

5. Legal Prohibitions in Certain Jurisdictions

According to the International Building Code, a maximum of two shingle layers are allowed, subject to certain caveats. However, your local building code may allow no more than one layer.

Beware of unscrupulous companies who only remove shingles around the edges of roofs before applying the new shingles, thereby simultaneously defrauding you and placing your home in violation of the code. As an ethical Lehigh Valley roofing company, we always strip all the old shingles off your roof before laying new ones.

In Conclusion

Shingle layover is a surefire way to damage your roof and the rest of your home, diminish property value and curb appeal, and potentially leave you without homeowner insurance and violating building codes. As a leading Lehigh Valley roofing company, we strongly advise against it.


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