Nothing goes through the panel
A metal roof is built to shed water with as few holes as possible. Every screw, nail or staple you add is a new one, and a new hole on a roof that freezes and thaws all winter will leak. Every method below holds on to something that is already there.
What holds lights on a metal roof
Standing seam clips. Standing seam is common on Vermont houses. It is the kind with raised ribs running from ridge to eave. Purpose-made clips clamp onto the rib and carry the light line along the bottom of the roof, one clip per seam. No glue, no screws, and they come off in January without a mark.
Magnetic clips. These snap onto the socket of a C7 or C9 bulb and hold to the panel with a magnet. They only work on steel. Aluminum, copper and zinc will not hold one, and paint makes no difference. Test with a refrigerator magnet on a piece of the same metal you can reach from the ground, such as the drip edge or a porch roof. Wind and sliding snow can shift them, so keep the line snug and the clips close together.
Gutter clips. If the eave has a gutter, clip to the gutter lip and leave the roof alone. The same clip works on any house.
Drip edge and fascia clips. Without gutters, the metal drip edge along the eave and the fascia board behind it will both take a clip. This is the usual answer on a barn or a camp.
Adhesive hooks stick to clean, dry painted metal, but they need a warm surface to bond and a Vermont November rarely offers one. Keep them for trim, not the roof.
Do not walk on it
A metal roof is slick when it is dry and worse with dew, frost or snow, and in Vermont the panels can hold frost on a November morning long after the ground has thawed. Everything on this page is done from a ladder set at the eave, on firm level ground, with someone holding it. If a run cannot be reached from the ladder, it is not a Saturday job.
The order to do it in
Measure the eaves you want lit and find the route to an outdoor outlet. Test the magnet and pick your clip. Fit a clip to every socket on the ground, then start at a corner and work along the eave, moving the ladder rather than reaching. Finish at a corner or a peak and put it on a timer.
The rest - line cut to length, no slack, one color of white - is the same on any roof, and shingles get their own clips. How professionals hang Christmas lights covers both.
When to hand it over
A single-story camp with gutters is a ladder job. A two-story standing seam roof with no gutters and a steep pitch is the kind of house people call an installer for.
