The 17 Most Common Roofing Mistakes

Putting a new roof onto your home is expensive, but will be necessary at some point. Unfortunately, some common roofing mistakes can lead to shoddy or amateur workmanship, which in turn will lead to higher costs when you have to go back and fix it.

Most mistakes have to do with water damage. A roof should protect your home against all kinds of weather, and most importantly keep you dry. Water in your roof, attic, or home can lead to mold, water damage, and costly repairs.

Here are seventeen of the most common roofing mistakes you should avoid.

1. Not Removing Old Shingles

While it might be legal in some areas to place new shingles over existing ones, it is one of the biggest mistakes in roofing. The proper way to replace any roofing shingles is to remove the old and replace them with the new.

This should be the standard when you are getting work done on your roof and is absolutely necessary when you are trying to repair the damage. Placing new shingles on old ones creates crevices and areas for moisture and dirt to collect. This will lead to your roof deteriorating and getting damaged faster, and potentially lead to more expensive repairs in the future.

2. Reusing Old Flashing

Flashing is a thin material, typically aluminum, that helps prevent damage to your roof and other roof features like vents, chimneys, and skylights. The biggest job of flashing is to redirect water to help prevent water damage and leaks.

A common roofing mistake is to reuse the old flashing. While the existing flashing might appear to be in good condition, it is a best practice to replace the flashing along with the roof shingles or tiles. If the flashing is reused, you run the risk of some potential issues with water damage or leaks in your roof.

3. Securing of Flashing

Flashing plays a very important role in the quality and safety of your roof. Not only should you always use new flashing, but it’s also important to make sure it is installed properly. If it is misaligned, improperly overlapped, or not fastened correctly, then your roof won’t be protected against water damage from ice, rain, or snow.

4. Imprecise Nail Placement

There are exact locations nails and fasteners should be placed when applying a new roof. If nails are placed in the wrong location, it can cause structural issues. One of the biggest issues is placing the nail where it is exposed to the elements rather than being placed underneath the top layer of shingles. If they are exposed, they can corrode and lead to holes in your shingles, which will make it easier for water and wind to damage your roof.

5. Incorrect Nail Length

For each style of shingle, there is a corresponding style and length of nail. If an improper nail length is used, there is an increased risk of shingles loosening. This will lead to shingles shifting, which will ultimately reduce the lifespan of your roof. Nails should go well into the decking to be able to securely hold the shingle in place.

6. Mismatched Slate Coloring

If you have a slate roof, rather than a shingled roof, a major concern with roofing is getting slates that match. While there is no harm in having slates of different colors, it will lead to your roof looking spotty, checkered, and mismatched.

When you are picking out slates, double-check if the color matches your existing roof or matches the batch you are going to use. Even with slates from the same source, there is a risk the coloring is not the same for each batch.

7. Poor Attic Ventilation

Your attic is an essential part of your roof. If you forget about it, it can lead to damages and a shorter lifespan of your new roofing. Your attic plays an important role in making sure the tiles or shingles on your roof have a solid foundation.

Your attic should be well ventilated. Without ventilation, your attic can become too hot, which will lead to excess heat build-up, and can damage your roof. This can also ruin your attic’s insulation which will only increase your energy costs until it is repaired. This is the number one cause of premature shingle and roof decking failure.

8. Failing to get a Roofing Permit

A roofing permit makes sure you get a roof that is safe for you and follows local building codes. In most areas, a permit is needed to install a new roof. If you are caught without one, the installation of your roof can be immediately put on suspension no matter the current condition of the roof, resulting in further fines and fees. Local municipalities may or may not require a permit for roof replacement. Be sure to use a licensed, insured and bonded roof specialist.

9. Not installing a Drip Edge

A drip edge is made of aluminum installed at the edge of the roof. Their job is to redirect any water away from the wall of your home and into the gutter. Without a drip edge, water may end up under your shingles and can cause damage to your home. Some older homes don’t have a drip edge installed, but it is required in most modern building codes. A drip edge also makes sure that wind-driven rain doesn’t get up and under your roof.

A common roofing mistake with drip edges is to not install them. This can save money in the short term, but the potential damage caused by not having a drip edge is not worth the risk.

10. Failing to Use Starter Strips

Eaves are the overhang on your roof and are the starting point for roofing. Unfortunately, a common roofing mistake comes when starting the roofing project. A starter section of shingles should always be laid along the eves and rake edges. Starter strips are not the same as regular shingles and are used to seal the first course of shingles along the eave. Without a starter strip, water may make its way onto the roof deck and lead to water damage.

11. Not Adding an Underlayment

A common mistake in roofing is to apply your new roofing directly to the wooden deck of your roof. Once the existing shingles or tiles are removed, a layer of underlayment should be applied before any new materials are added.

Roofing underlayment adds a water-resistant or waterproof barrier that the rest of your roof can be built on. This important layer helps protect your home and roof and helps your roof have a longer life.

12. Not Following Manufacturer’s Guidelines

Everything that goes on your roof has instructions that should be followed. It can appear as small print on the boxes or packaging the equipment comes in, but it is necessary information. Some people consider themselves experts on roofing, and they ignore the directions of the manufacturers’ instructions. Ignoring the manufacturer’s guidelines leads to improper installation and can lead to an increased chance of damage.

Some roofing supplies provide warranties, but it requires the guidelines to be followed. If the materials are installed or handled improperly, the warranty is typically voided.

13. Not Considering the Slope of the Roof

A common mistake with roofers is to assume that what works on one roof will work on all homes. This is not the case. The slope of your roof changes the materials used in roofing your home. Lower slopes allow for roll roofing with exposed nails, while higher pitches are reserved for shingles and tiles. Choosing the wrong material for the slope of the roof can leave the roof open to water penetration and damage.

14. Not Addressing Ice Dams in Cold Climates

In cold climates, ice damming is common. When the snow melts on your roof but refreezes, it can force water and ice under the shingles. This can pull shingles up, and add unnecessary weight to your eaves and gutter system. When you’re installing a roof, you should take steps to prevent ice dams. Attic ventilation can help with avoiding this because with a cold attic you won’t get as much snow melting. You can also include an adhesive ice-and-water barrier to cover the edge of your roof. In most regions, especially colder climates, this is even required by the building code.

15. Poor Shingle Alignment

One of the easiest ways to see a poor roofing job is to look at the shingle alignment. If the cutouts on shingles are not vertical or if the joins aren’t on the same horizontal plane, the shingles are misaligned. While this can visually make your roof look unorganized and sloppy, it’s also a problem with coverage and protection of your roof. Misaligned shingles create cracks and gaps in roof coverage and provide places for water to cause damage to your roof, roof deck, and home.

16. Incorrect Shingle Exposure

Shingles have recommended lengths they should be exposed between layers. If they are too clustered together, which shortens the exposure, your shingles are vulnerable to collecting moisture during a rainstorm or being blown off. If your shingles are too far apart, your roof is not getting the protection it needs and there is potential for water damage.

17. Improper Shingle Overhang

Shingles shouldn’t stop at your roof edge. They should hang over the roof, even if there is a drip edge. A common mistake with roofing is to either cut the overhang too short or too long. Too much overhang increases the risk of the shingles blowing off in high winds, and too little overhang allows water to seep into the rake or fascia boards.

DMG Exteriors Can Help

Your roof protects your home, your family, and everything you hold dear, and so it needs to be installed correctly. Contact our experienced roofing team at DMG Exteriors so we can help you get the service you need to protect what means most in your life.

We can also help with all of your siding repair, replacement, and installation needs. For over a decade, we have provided exceptional service paired with top-quality work and craftsmanship. Compared to our competitors, we are the leading choice for all types of exterior and interior home contractor services. Schedule your free estimate with us today.