Never Clean Your Gutters AgainGutter Guard Installation in Grimes, IA

Mixing metals invites corrosion

Most gutters here are aluminium. Many micro-mesh guards use stainless steel cloth, because stainless resists corrosion and holds a fine weave. Putting those two metals in contact, outdoors, in the presence of water is the textbook setup for galvanic corrosion: the less noble metal, the aluminium, gives up material to the more noble one. In practice good products manage this and it is not a reason to avoid stainless mesh. It is a reason to care how the guard is built and fastened. The mesh should be isolated in its frame rather than pressed directly against the gutter, and the screws should match the metals they are joining rather than being whatever was in the van. Steel screws into aluminium gutter in a wet joint is the most common version of this mistake, and it shows up years later as staining below the fastener and a hole that will not hold. It is invisible on the day of installation, which is exactly why it is worth asking about beforehand.