The Difference Between Seamless Gutters and Non-Seamless Gutters


Seamless Gutters vs Regular Gutters

In the traditional world of roofing seamless or continuous residential gutters have been around for many years. They offer longer lengths thus eliminating joints that eventually fail and leak. Usually in the most annoying spot like over a doorway or window. Before the advent of seamless gutter machines, non-seamless gutters were the only option. Usually installed 10’ lengths, these gutters were made primarily of materials that could be soldiered in the joints thus creating a permanent leak free connection. These materials would include galvanized steel, stainless steel & copper. However, due to the high cost of labor to assemble and install them, seamless aluminum gutters became the norm. Seamless aluminum gutters, typically 5” (12K) and 6” (15K) also had the advantage of being pre-painted in many colors thus eliminating the need to repaint them every couple of years.

In the world of commercial and industrial roofing seamless residential gutters were an option but usually the size of the building would prohibit their use since they lack the capacity to handle the volume of water coming off the roof. So contractors were back to 10’ lengths of fabricated commercial gutter that can be formed into an unlimited array shapes and sizes. Again, the same problems occur. Joint leaks unless the material could be soldiered as well as the high cost of labor to assemble and install them. With the introduction of pre-painted steel and aluminum sheets, these fabricated gutters could now be formed pre-finished but the joints have to be pop-riveted or mechanically connected by another means to hold the joints together. The joints were then sealed with a flexible sealant to keep the joint from leaking. Even the best sealants eventually fail and become a constant maintenance issue. However, gutter leaks will still occur usually over the owner’s doorway or office window.

DMI saw this industry wide issue and an opportunity and invested in a custom build commercial gutter roll former capable of roll forming 7”, 7-1/2” and 8” SMACNA “E” style gutter (slightly modified shape). Our seamless gutter can be roll formed in .032 & .040 pre-finished aluminum, 24 & 22-gauge pre-finished steel and 16 & 20-ounce copper and in any of our 32 standard colors as well as custom colors. Lengths of up to 52’ are available. The gutter can be formed with a 3” x 90-degree roof flange or with a straight back. It is designed for use on standing seam roofs, shingle roofs, or any kind of sloped roofs. Also, this product works well with flat roofing projects using any of the current roofing systems available on the market today. This allows the installer the flexibility to custom order gutter lengths to the exact length needed. On longer building sections, expansion joints are built into the exterior walls. At these expansion joints, gutter sections can be formed so that the gutter expansion joints align with the building expansion joints. The gutter installs easily and is a very cost effective in terms of labor savings. Gutter leaks are virtually eliminated.

If the “E” style gutter shape is not acceptable, DMI can fabricate virtually any shape and size gutter in lengths up to 32’. A wide variety of painted and unpainted material can be used which include, pre-finished steel and aluminum, copper, stainless steel, zinc, paint grip steel and both mill-finished steel and aluminum.

Along with seamless gutter, DMI offers a complete line of accessories. These include gutter straps, under gutter brackets (painted or unpainted), end caps, gutter expansion joints, down spouts, down spout outlets, down spout elbows, down spout straps, sealants & painted pop rivets. DMI square or rectangular down spouts can be fabricated in lengths up to 30’ which eliminates the need to connect multiple pieces of down spout on most applications.

DMI stands ready to supply your gutter needs. We are confident that we can meet and exceed your expectations. Please contact your local territory manager or call us at 800-828-1510. Also, visit our web site at and view our complete line of water control products as well as our standing seal roofing systems, wall panels systems, ES-1 certified edge metal systems, and almost every accessory needed to complete your installation.

AIA Continuing Education

DMI is committed to providing you with high-quality expert-level education in accordance with the AIA/CES standards. The courses we offer are designed to meet the needs of architects and typically run one hour in length. All Attendees will earn 1 Learning Unit. Some of the courses offered will meet the Health, Safety, and Welfare (HSW) requirements as well as the Green Building Certification Institute (GBCI) credits.

information on available courses

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