The Pros and Cons of Metal Roofs

Thinking about metal roofs for your home? The best tip I can give you is to “Think It Through.”

Multiple feet of snow have built up on your asphalt roof this winter, so you might be thinking about changing to a metal roof because you know that the snow “slides” right off. The blessing of a metal roof is that the snow does, in fact, slide off. The curse of a metal roof, however, is that as the snow slides off, it doesn’t do it gently, but rushes off like an avalanche, tearing off decks, crushing bushes and flattening anything else in its path.

Installing a metal roof may solve one problem but may create other unforeseen ones. Of main concern is the pitch or steepness of your roof. Most New Hampshire roofs are pitched so they barely allow a person to stand erect in the center of the attic. At this pitch the snow on your roof will be six inches to several feet thick before sliding off. Once the combination of heavy snow and frozen snow lets loose it has the power to tear decks off the house and cause terrific damage. Many years ago the insurance companies declared that they would only pay for one sliding snow issue per policy, which is something to consider as you make your decision.

If you’re going to go ahead with your plan to change to metal roofs do your homework first. Here is a partial lesson plan:

  1. When the snow slides off where will it fall and what will it block: front door, garage doors, dog run?
  2. What will it fall on: bushes, railings, your car, your pet?
  3. Is it feasible to modify the design of your roof to channel the snow and water runoff to go where you want it to go?
  4. Snow guards work but don’t put in too many; they could also be ripped off with the sliding icy snow.
  5. Chimneys must be flashed to cover existing lead flashing; otherwise, oxidation will occur causing your new metal roof to discolor.
  6. Ventilation in your attic is a critical issue; be sure that your contractor doesn’t block the ridge vent if you have one. If you don’t have a ridge vent, consider ways to improve the attic ventilation. More on that in a future article.

Doing your homework before you make the switch to a metal roof will ensure success, and bring a smile to your face every time you hear the snow slide off your roof, or scare you silly!