Choosing and Living With a Roof
Lesson 19. Choosing a Material for This Climate
In this valley a roof has to survive hail, straight line wind, ice and a hundred degree attic, and that narrows twenty six materials down to about four.
At a Glance
- Structure first. Weight rules out half the list immediately
- Slope second. Under three in twelve, no shingles
- Then how long you are staying, which decides the money
- Impact rated products can lower your insurance premium
Four Questions, In Order
- What will the structure carry. Slate, clay and concrete tile need an engineer's opinion. Everything else does not
- What is the slope. Under three in twelve you need a membrane and not shingles
- How long are you staying. Under ten years, buy a good asphalt roof. Over twenty, metal starts winning
- What does your insurer reward. Impact rated products often carry a real discount here
What This Climate Does
| The Weather | What It Attacks |
|---|---|
| Hail | Granules and the shingle mat. Impact rating matters |
| Straight line wind | Seal strips, edges and ridge caps |
| Freeze and thaw | Anything porous, and every joint |
| Ice damming | The eaves, and what is under the shingles |
| Summer heat | Asphalt, from underneath, through the attic |
| Humidity | North slopes, through moss and algae |
The Short List for a House Here
- Impact rated architectural asphalt. The right answer for most houses
- Standing seam metal. The right answer if you are staying, and the best against ice dams
- Stone coated steel. The best hail performance if that is your main worry
- Synthetic slate. The right answer on a historic house that cannot carry real slate
That short list covers most houses here. Everything else on our materials list has a narrower job. Some of it is for flat roofs. Some is for shops and barns. Some suits one style of building and nothing else.
Work down the four questions in order and the answer usually picks itself. Structure rules things out. Slope rules more out. How long you are staying decides the money. What is left is a short list, and any of it will do the job.