The roof is the first line of protection against sun, rain, hail and wind, but it is usually the last thing a homeowner thinks about. Much of what people believe about roofs turns out to be myth. Most homeowners only buy one or two roofs in their lifetime, so bad decisions are costly: moisture problems, high energy bills or structural damage. At Roof Experts, based in Arlington, TX, our team works with homeowners across Dallas-Fort Worth, including Haltom City, on all their roofing projects, including repairs.
There are a few ideas about roofing repairs that aren’t entirely accurate. To help homeowners and business owners in the Dallas-Fort Worth area who need roof work, here are three of the most common myths. Understanding them goes a long way toward getting repairs done right the first time.
Myth 1: New Shingles Can Always Go Over The Old Ones
Think of shingles like the skin of an apple. The skin can look bright and firm while the fruit underneath is soft and rotten. Under your shingles is a layer of wood decking, usually plywood or OSB, and it can rot from leaks, poor attic ventilation or plain age. Laying new shingles over old ones hides that layer. The only reliable way to inspect and repair the deck is to remove the old shingles. Building codes also limit when a roof can be re-covered, and a second layer adds weight and can shorten the life of the new shingles. That is why we recommend a full tear-off for most roof replacements.
Myth 2: All Asphalt Shingles Are The Same
Fiberglass-based architectural (laminated) shingles are better than ever, the result of a lot of industry research. Shingle lines still differ in thickness, wind rating and warranty, and many carry a limited lifetime warranty from the manufacturer when installed to its specifications. Impact-resistant shingles rated Class 4 under the UL 2218 test are built to take hail better than standard shingles, which matters in North Texas. Our pages on Class 4 impact-resistant shingles and CertainTeed shingles go into more detail.
Some shingles are made to fight specific problems. In warm, humid climates, black streaks from algae can appear over time. Algae-resistant shingles have copper-containing granules mixed in; rain carries a small amount of copper across the roof surface, which discourages algae growth. Other shingles are designed to look like wood shakes or slate.
Myth 3: More Attic Insulation Is Always Better
Adding insulation can backfire if it is piled over the soffit vents and blocks airflow through the attic. Trapped moisture can then rot the roof deck and rafters and feed mold. Insulation and ventilation work as a pair, and adding more of one does not fix a problem with the other. Insulation is rated by R-value, its resistance to heat flow: the higher the R-value, the better it insulates. The R-value you have now depends on the type of insulation and its depth. Adding another layer of fiberglass seems logical, but in a poorly ventilated attic, warm, moist air from the house can condense on the cold underside of the roof deck in winter. Proper ventilation keeps attic moisture and temperature in check year-round. Vents and fans are rated by Net Free Area (NFA) in square inches, and an attic needs enough intake at the eaves and exhaust near the ridge. Signs of poor ventilation include mildew or dark staining on the underside of the deck, frost on roof nails in cold weather, and an attic that is far hotter than outside on summer afternoons. Our post on replacing attic insulation covers the basics.
If you’re planning a roofing project but aren’t sure how to move forward, don’t try to figure it out alone. Contact our team at Roof Experts for a free roof inspection, or call (817) 754-9484.