Garage Door Seals - Types and Tips

​Garage door weather seals are simple and straightforward components, but they are critical to the effective performance of the door. These important parts act as a means of protecting the garage area and sealing out the elements. When it comes to residential garage doors, there are really only two main types of weather seal. 
 
Stick around for this brief discussion as we dive into the common types of seals, as well as discuss a largely unknown type of weather seal that can really help if you are struggling to keep water from coming in under your garage door.
 
Common Seals

Bottom Rubber Weather Seal

A. Bottom Rubber Weather Seal
At the bottom of garage doors is a strip of rubbery weather seal that runs the entire length of the bottom section. This is sometimes referred to as an “astragal.” Depending on the manufacturer, this is made in different colors (typically black or gray) and it comes in different configurations. Many times, this weather seal is “U” shaped and has “T” shaped ends (see picture below) that slide into an aluminum retainer that is attached to the bottom of the door. Other types of bottom seal have a more circular or bulb shape that comes together at the top and slides into a bull nose, a “T,” or a circular shaped insert that slides into the retainer at the bottom of the door. The shape of the slot(s) in the retainer must naturally match the weather seal and the differing weather seal end profiles are normally not interchangeable. Although there are other types, the “T” and circular or bull nose varieties are common.

Stop Mold

B. Stop Mold 
This type of weather seal is most commonly made from durable PVC and consists of two primary parts. The largest portion is a rigid piece of thicker textured PVC that provides structure. Integrated into this rigid portion of the stop mold is a thinner highly flexible flap (see the picture below of a white version) that extends out and presses against the garage door exterior surface to create a sealing effect. 

Stop mold is attached to the exterior framing immediately on the exterior of a garage door both on the sides and on the top. Stop mold is most commonly ordered in a color that matches the exterior color of the garage door, which helps the stop mold aesthetically blend into the overall look of the door.
 
Although most stop mold used today is made of PVC, there is also wood stop mold which is intended for use with real wood garage doors and it can be stained to match the finish of the garage door to blend in.

Threshold

C. Threshold 
There is a third type of weather seal that is not as common, but nonetheless can be a huge factor in keeping the elements at bay. This is called threshold, and as the name implies, it is installed at the bottom of the door opening. Garage door thresholds are made of a very dense and tough rubbery composite material and can be cut to any length to accommodate garage door openings of all sizes. This product is normally glued to the concrete floor with a heavy-duty adhesive, which must be applied above a certain minimum temperature. This excellent weather seal option helps prevent water infiltration under the garage door and it can be used in conjunction with the normal bottom rubber weather seal.

Weather Seal Tips
 
A. Check the Bottom Seal Periodically
Similar to the tires on your car, the rubbery seal at the bottom of your garage door should be checked periodically for wear, tear, and damage. Over time, this seal can become dry, brittle, and even hard. We’ve also seen this type of seal fall victim to the destructive behavior of rodents or other animals.
 
In addition, bottom weather seal can be severely damaged if it becomes frozen to the concrete floor during the cold winter months and the door is opened. This can tear the weather seal and even damage the door and the opener. Care should be taken when freezing temperatures exist to avoid this issue and ice melting techniques should be used to prevent damage.
 
The key to keeping your bottom weather seal and garage door performing at its best, is to periodically inspect the seal for signs of wear and damage. If the weather seal is damaged or it’s starting to look dry and brittle, consider replacing it soon. Whether you replace it yourself or hire someone to do this for you, it is much easier to replace before the rubbery material becomes dry and hard. If the bottom weather seal gets too hard or too badly damaged, it can be very difficult to remove from the aluminum retainer and trying to do so can potentially cause serious damage to the retainer during the removal process.
 
B. Ensure a Proper Fit and Finish of Stop Mold
Like the bottom rubber weather seal, it is important to periodically check the stop mold that frames the sides and top of your garage door. If it looks damaged or shows signs of excessive wear (e.g., cracking, tearing, etc.), it should be replaced to ensure the best performance – and appearance.
 
Whether assessing the condition of either existing or newly installed stop mold, it is important to make sure there is a tight-fitting seal, but not too tight. If the stop mold is installed too tightly against the door, this can put undue pressure on the door when it opens and closes and excess friction that can damage the stop mold and possibly even the door over time.
 
When replacing worn or damaged stop mold, ensure that the trim nails used to affix the stop mold to the framing of the garage door opening are made of stainless steel. This is critical, as nails made from regular steel can and will rust over time, leaving unsightly rust stains on the trim and possibly even the garage door exterior surface. Stainless steel trim nails are available is a variety of colors to help match the color of the stop mold. This quality product is an essential element of installing the stop mold to ensure a long-lasting, visually pleasing finish.
 
Lastly, if the stop mold is a darker color, such as black or dark brown, it should be made from a “high-heat” formulation to help minimize buckling from expansion and contraction due to sun exposure and temperature changes. Additionally, using a tighter nailing pattern (e.g., a nail every 8” versus every 12”) when attaching this darker color stop mold can help avoid buckling and deformation.
 
Conclusion
We hope you’ve enjoyed this article and found the information helpful. Whether it’s bottom weather seal or stop mold, periodically checking and replacing these important parts is essential to ensuring your garage door performs at its best. And keep in mind the additional layer of protection offered by the clever threshold product.
 
We are happy to answer any questions you may have about garage door weather seals.  We offer a full line of weather seals and garage door services to help you get the most out of your garage door.