Snow rails, sometimes known as snow guards, can be purchased in either metal or plastic formats, depending on the type of roof you have. Though metal snow rails are very popular, it is often found that plastic snow rails work best on metal roofing and so it was necessary to make the plastic ones available to the masses. The plastic snow guard came into vogue in the mid seventies when it was found that metal guards were getting brittle and breaking in the cold. They were also causing intense metal reactions that ended up corroding the metal roofing. In this kind of instance the conductive fluid or electrolyte is generally rainwater. During the process of vaporization the water generally becomes more concentrated and therefore more conductive, meaning that the (originally) benign causes a galvanic effect, which leads to rusting and damage.

This problem usually happens when water pools into a crevice or gets stuck under a bolt meaning that moisture is touching both metal surfaces. Sometimes water that is simply touching a metal guard and drips onto a metal roof can lead to the slow corrosion of things. Originally, even painting metal guards didn’t really help, though it definitely slowed the problem down. Instead, points of friction simply began to deteriorate first, and eventually the metal guard would become useless and detrimental to the roofing itself.

In normal circumstances, the reliability of the metal snow rails was entirely dependent on the location of the home on which they were placed. This is because geographical location plays a large part in the rate at which corrosion occurs, meaning that areas with lots of salt water and pollution are the worst off. Homes on the coast with all the sea air generally had the most rapid rates of failure.

Because of this and the following reasons, it was important that an alternative option became available for use on metal roofing. One of the main problems was that if a metal snow guard makes contact with a dissimilar metal type roof panel, a galvanic corrosive reaction (i.e. rust) can occur and prematurely eroded and stain the roof. With plastic guards, this galvanic reaction does not occur. Also, in the cold weather, metal guards (especially cheap castings), may become very brittle, fracture and break. They are normally fine on roofing that isn’t metal, but plastic does not get brittle in the cold and is better on metallic roofing.

Though metal guards were useful on asphalt or tile roofing but not metal, they were still popular because of the facility to change their color to match the color of the roofing. Some plastic guards give you this option, but many people that choose plastic guards go for the clear ones, as these don’t show up very much. It really depends on personal preference and what you think looks best on the roof of your home.

If you’d like more information on snow rails and what the best options are for your home, then look online or ask a local roofing expert.

Learn more about snow rails. Stop by Lucy Cho’s site where you can find out all about snow rails and what they can do for your home.