Take a minute to get a good look at the inside your raincoat. How can you tell if the product you thought was supposed to be keeping the rain out is actually doing what it’s advertised to do?
Just because your jacket looks and feels like it does the trick in the rain, it may be lacking certain enhancements that are absolutely necessary to ensure that you’ll be kept dry even in the dampest conditions.
There are a lot of factors that will determine how effective your jacket is at keeping water at bay, but one of the most vital components that must be present are sealed seams or waterproof seam sealing tape.
When a jacket is constructed, pieces of fabrics are usually stitched together. The stitching results in punctures in the fabric which can allow water to seep in, causing you to get wet inside the jacket. These seams can be sealed using a special waterproof seam sealing tape (referred to as tape sealing).
Alternatively, a jacket can be constructed using the process of heat sealing - which may or may not involve stitching fabric together, but always involves the fabrics being “welded” together (or onto another material such as plastic) with heat.
Since there are two ways seams are sealed, it is important to take note of what you visibly see on the inside of the garment. If there are taped seams, companies will make use of a waterproof tape, placing it along the seams that need to be sealed. To ensure that the tape stays put and airtight, they will expose the tape to a degree of heat or special glue during the application process to seal them. If a garment has welded seams, there will be no tape present but the seams will be directly sealed together using heat.
There are three terms to discuss when examining the topic of seam sealing: fully taped seams, critically taped seams, and welded seams. Each is distinct from one another, yet they all serve the same purpose, to keep water out. Let’s examine what the differences are.
This type of sealing involves a process where the waterproof tape is glued and/or heat bonded to each seam - almost as if it is welded to the jacket, which completely covers the holes left by the sewing needle. Through this process, the seals become completely secure and make the garment at least as water-resistant as the fabric itself.
Almost like fully taped seams, this type of seam sealing utilizes heat and pressure in order to bond the garment seams. This implies that there are no stitch holes, no straggling threads, no seam tapes, and no sewing machines.
This type of sealing does not work with every material, but most thermoplastics are weldable. Polyurethane is one such material and is commonly used by outerwear companies in their layering/sealing processes. This is why you may come across the term “plastic welding” when examining the label of your jacket. The plastic itself is the bonding agent, and once heated, holds the seam tightly together.
In this sealing process, only the critical seams are taped (areas that are most prone to cause water seepage) . In most cases, these sealed seams are found commonly in the hood, around the neck and over the shoulders (areas where rain would most likely penetrate the exterior of the jacket).
From a consumer standpoint, checking to see if your garment is seam sealed with tape is simple enough. Check the inside of your jacket. In most cases, if it looks like there is tape running all along the interior lining, that’s a tell-tale sign of seam sealing. The tape should look and feel as if it is completely adhered to the fabric, almost like it was vacuum-sealed on.
While checking to see if a garment was seam sealed with tape is easy, seams that are welded are more difficult to detect. Welded seams, when done properly, should barely be noticeable.
Quality rainwear is hard to find, especially when there are so many technical details to understand. There are racks and shelves of products that advertise one thing, but can’t deliver once the rain starts coming down. As a consumer, it would be wise to pay close attention to crucial details, such as what labels say, what the interior looks like, how thick the jacket is, and how warm it will keep you. Once you begin to check for overlooked features like these in your outerwear, you’ll start to become more confident when purchasing that jacket for the next wet day.