Most siding damage in Southeast Michigan doesn’t happen in a single dramatic storm. It happens slowly, one winter at a time. By the time you notice a stain inside or a soft spot under a window, water has usually been getting behind the siding for a while. Understanding what winter does makes it easier to catch problems early.
Freeze-thaw cycles
Through a typical Oakland County winter, temperatures swing above and below freezing again and again. Water that gets into a crack, a gap at a window or behind a loose panel freezes, expands and pushes the gap open a little more. When it thaws, more water gets in. Repeat that through a winter and a hairline gap at a J-channel can become a path into the wall.
Ice dams
When heat escaping from the attic melts snow on the roof, the meltwater runs down and refreezes at the cold eaves, forming an ice dam. Water backs up behind it, sometimes under the shingles and down behind the fascia and the top courses of siding. Stains at the top of exterior walls and peeling paint near the ceiling inside are classic signs. The long-term fix is attic insulation and ventilation, but the siding and trim may need repair too.
Snow piles and the bottom courses
Snow plowed or shoveled against the house sits on the bottom courses for weeks. As it melts, water wicks up behind the siding and soaks the sill plate and sheathing at the base of the wall. Wood trim at grade and fiber cement installed too close to the ground are especially vulnerable.
Cold-weather cracks
Vinyl gets stiffer as it gets colder. Hits that wouldn’t hurt it in summer, from a snow blower, a shovel or ice falling off the roof, can crack it in January. Thicker and insulated vinyl resist this better. See our vinyl siding guide for what to look for when you replace.
Pile snow away from the walls, and keep the snow blower chute aimed away from siding. It’s the easiest way to prevent winter damage.
The spring walk-around
- Look for cracked, holed or missing panels, especially near driveways and walkways.
- Check corners and gable ends for loose pieces after late-winter winds.
- Press on the bottom courses and trim for soft spots.
- Look for stains at the top of walls and under eaves from ice dams.
- Check window and door trim for gaps and failed caulk.
- Look inside at closets and corners on exterior walls for stains or musty smells.
- Clean gutters and make sure downspouts carry water away from the walls.
Small problems found in spring are usually quick siding repairs. If you find damage on several walls, soft sheathing or siding that’s past its life, it may be time to look at siding replacement.
When winter damage means a bigger problem
One cracked panel by the driveway is a quick repair. But if you find soft sheathing at the bottom of several walls, stains at the top of walls every spring, or siding that cracks somewhere new every winter, the problem is bigger than the panels. It may be thin, brittle siding near the end of its life, missing flashing, or an attic that keeps creating ice dams. That’s the time to have a contractor look at the whole wall system, not just the visible damage, and to fix the cause along with the siding so the same damage doesn’t come back next year.
Preventing winter damage
- Keep gutters clean in late fall so meltwater can drain.
- Improve attic insulation and ventilation to reduce ice dams.
- Re-caulk gaps around windows and trim before winter.
- Fix loose or cracked panels in the fall, not after the snow.
- Keep shrubs trimmed back from the walls so they dry out.
For more on how siding holds up across the county, visit our Oakland County siding guide.