There are companies who offer roofing services at a discounted priceSchedule an appointment with a professional roofer. Unfortunately, they may not be trained in the proper installation of a roof system or know what materials are appropriate. As a result, your new roof could deteriorate sooner than expected and will leak over time.


Installing shingles on a low slope roof

Roofing shingles are not meant to be a waterproofing element of a roof. Rather, their purpose is to divert water down the slope of your roof into your gutter system and away from the foundation of your home. When a roof pitch is too shallow (roofs with a pitch (slope) of less than 3:12 are considered low–slope roofs) shingles are not the proper roofing material. We recommend a TPO (Thermoplastic Polyolefin) membrane roof specifically designed for low slope roofs. If shingles are installed on a low slope roof, water is going to find its way under the shingles and cause roof leaks. Most homeowners know that they have a low slope roof and that shingles aren’t appropriate. Don’t let someone sell you something you know is wrong. Schedule an appointment with a professional roofer.

Not Installing Drip Edge

Drip edge is critical to provide a finished look, to add waterproofing and most shingle roof manufacturers cover this in their installation instructions. Drip edge is recommended at eaves and rakes and serves to prevent unwanted insects and pests. It also helps to prevent rain from entering under the edge of the roof, as a barrier (no exposed wood) and a drip/leak point for water. It also keeps shingles from sagging where they extend over the roof deck allowing water to properly drip into your gutters. There are companies who eliminate this from their bids in order to reduce their price to the consumer. Review the details of your estimate to ensure it is included in your new roof installation.

Using the wrong starter course material

Shingles manufacturers sell starter shingles and provide instructions for their proper installation. Starter strip shingles include a high-quality, properly positioned adhesive that will tightly lock your shingles in place to help prevent blow-off. We recommend this method. Some roofing companies try to cut corners and use the cut shingle method.

Not installing ice and water shield

Roof leak barriers (water and ice shields) help prevent wind-driven rain and melting ice and snow from leaking through the roof. It’s important to install this around skylights, chimneys, plumbing vents, ventilation caps, or anything that penetrates up through a roof. Failing to do so can lead to leaks so be absolutely sure it is installed as part of your new roof.

Improper Nailing

One of the most common defects in the installation of an asphalt shingle roof is improper nailing, which compromises the integrity of the shingle. Examples of improper nailing include nails driven in at an angle, overdriven nails, high nails that aren’t driven in far enough and nails that are installed in the wrong location on the shingle. All of these errors can lead to shingle tearing, come apart and can cause the appearance of the finished roof to look poorly installed.

Improper handling of the valley areas of a roof

Valleys are a prime area for leaks, so it’s important to be careful and take your time. Valleys collect snow and are loaded with water during a storm. Valleys are a problem area because cut shingles within a valley create an edge for water to get under the shingles. The shingle edges must be properly sealed. We adhere to the installation methods recommended by GAF which include the open, woven, and closed cut methods. It goes without saying that you should never put nails in the valley area of a roof.

Bad Flashing Details

Flashing is used to seal and protects joints in a building from water penetration by directing the flow of water away from these otherwise vulnerable areas including at chimneys, roof vents and under shingles at valleys. It is never a good idea to reuse old flashing unless it is in like new condition. This means it is not buckled, rusted, bent, cracked or broken. A leak barrier should be installed over the roof deck and up against any adjoining wall surface. Likewise, an adhesive leak barrier should be installed at vent stacks and valley areas (open valley) before applying shingles.

Lack of a Saddle Installation Behind Chimneys

A saddle is a ridge structure built behind a chimney and its primary purpose is to divert water on a roof around a chimney or the transition from one roof area to another. Smaller saddles are often covered with metal flashing, and larger saddles are frequently covered with the same material as the rest of the roof. The underlying structure of a saddle can consist of wood or metal.

Poor Attic Ventilation

Poor attic ventilation leads to an overheated attic. That combined with moisture build-up in the attic can lead to premature rot of roof decking and shingle damage. The moisture in a non-ventilated attic can also lead to mold development. The heat that’s absorbed in the attic can also radiate into the living space causing air conditioners, fans, refrigerators and other appliances to work harder. The end result is higher energy bills.

Using 3-Tab or Dimensional Shingles Instead of an actual Ridge Cap Shingle

A non-professional roofer will use 3 tab shingles on the hips and ridges of roofs to save a few bucks. Because this area of your roof is so vulnerable to high winds you will occasionally see missing shingles from this area of a roof. This is most likely because 3-tabs shingles were used instead of a product designed specifically for this area. Shingle manufacturers have specialty products for hip and ridge areas of roofs. The GAF line includes TimberTex®, Seal-A Ridge® and Z®Ridge just to name a few.


Knowledge is vital and we firmly believe that staying up to date on the latest products and installation methods are an important part of qualifying as a professional roofer. We are GAF Master Elite Weather Stoppers. We warranty everything we install and have one of the best warranties in the industry. That’s because we know that what we install will stand the test of time.

Call us for a FREE, no obligation estimate. Our Office number is 703-215-9761.


You could hire a fly-by-night company, but you may regret it latter. Hire a professional roofer and give yourself peace of mind that your roof will be properly installed. Serving Fairfax, Northern Virginia, Maryland and DC.