What is a mechanical lock profile?
Mechanically seamed roofing systems have vertical legs that line up with each other and are seamed together with a hand or electric seamer. Using an electric seaming tool can allow for a tighter and more consistent seam than just hand forming them. The concealed clips are then a part of the mechanical lock system.
Mechanically seamed panels utilize clips to connect the panels to the substrate. For low-slope roofs, especially where there’s a chance of a heavy build-up of snow or rain runoff, mechanically seamed panels are the best choice since the two panel’s seam closes any space water may collect and lowers the risk of leaking between seams.
Single Lock vs. Double Lock
A single lock seam refers to the fact that there’s only one fold of the seam. It’s a 90-degree seam, and although this style won’t perform as well as a double lock profile, it does well in mild environments. You will need to check with the manufacturer to ensure the roof system’s engineering will allow for the use of a single lock profile. Some of the benefits of using a single lock profile are that they take less labor to install and are easier to replace should damage occur than the double lock alternative.
Double lock seams are those that have been folded over twice (or 180 degrees). They are best for low-slope building applications that may need to be extra weathertight. Double lock seams are much stronger for wind uplift and foot traffic and hold up better in extremely cold-weather regions. One consideration to make when using this type of panel is that they are more labor-intensive to install and replace. The double lock system is the preferred standing seam roofing choice in cold climates such as Montana. This is because metal will expand and contract in the freezing temperatures. The extra secure fit of a double lock system will keep the panels from coming undone. The weather-tightness will also keep out any moisture from melting snow on your roof that could cause leaks.
Advantages of a mechanical lock profile
Can be used for lower slope roofs – One advantage of using mechanical lock panel profiles is that you can use them on low slope buildings (those of 2/12 pitch and less) unless otherwise dictated by the project specifications or panel design limitations. Usually, a seam sealant will be required when going below a 2/12 pitch. Please check with the manufacturer for the minimum pitch they recommend.
Varying seam heights – Since this type of standing seam profile is seamed mechanically in the field, they can have varying seam heights. Higher seams may add more stability to the roofing system’s structure. However, if you don’t want your seam to be “bulky”, they can have a thinner seam that is narrow and low-profile.Better watertight capabilities – On low slope roofs, especially, the potential for water remaining on the roof can be problematic. In this instance, using a mechanical lock profile would be best since the way that these panels are seamed together allows for more watertight and waterproofing capabilities.
Using a seaming tool for installing mechanical lock profiles keeps the seam tightly closed, and thus closes the spaces where water might collect and reduces the chance of leaking into the roof structure. A sealant can also be added to the panels’ legs to further assist in waterproofing the roof.
Durable and strong profile – The way these panels are mechanically seamed together adds rigidity to the structure and makes them even stronger against high winds and hazardous weather. In this instance, expansion clips may be used to tolerate greater temperature changes when the standing seam metal roof system contracts or expands.
