Vinyl siding wins on price and upkeep. In a humid place like East Tennessee, its weak spots are heat, water that gets behind the panels, and mildew on walls that never see the sun. Here are the vinyl siding pros and cons, and what to ask before you sign for it.
What vinyl does well
- On most siding quotes, vinyl comes in below fiber cement and wood.
- It never needs paint. The color runs through the panel, so a scratch doesn't show bare wood.
- Most years, cleaning it takes a garden hose and a soft brush.
- It doesn't rot, which counts on the walls that stay wet.
- It comes in plenty of looks, from plain lap to board and batten to shake styles. Our post on siding styles shows the main ones.
For a rental, a first house or anyone who doesn't want to paint again, those are real advantages.
Heat and the reflected-sun problem
Vinyl softens when it gets hot enough. Panels are hung loose on their nails so they can grow and shrink with the weather, and in normal sun that's fine.
The trouble usually comes from a window. The siding trade group's cleaning and care guide warns that energy-efficient windows can concentrate sunlight and create intense heat on nearby siding. It shows up as a wavy, sagging patch in the same spot on a wall, often facing a neighbor's house.
The guide's fixes are low-tech: plant shrubs, or put screens on the window doing the reflecting. If that window belongs to the house next door, it's a conversation over the fence.
Water behind the panels
Vinyl siding isn't the waterproof layer of the wall. Rain gets behind it at seams, corners and around windows. What actually keeps the wall dry is the housewrap and flashing underneath.
The same care guide tells you to hold a power washer straight at eye level and never aim it upward, because that can force water behind the siding panels. That's a good hint about how the system works. Water behind vinyl is normal in small amounts. Water that can't get out is the problem.
In humid summers, a wet wall dries slowly. If the wrap is torn or someone skipped the flashing around a window, the sheathing behind the vinyl can rot for years with nothing showing on the outside. When you compare siding quotes, ask what goes on the wall before the vinyl, and what happens to any soft sheathing they find when the old siding comes off.
Mildew on north walls
A north wall under trees stays damp after a rain and gets little direct sun, so it grows a green or gray film. On vinyl, that's a looks problem, not a structural one.
For small spots, the care guide suggests a household spray cleaner. For bigger areas, it gives a mix of roughly three parts vinegar to seven parts water. A soft brush and a rinse take care of the rest.
A few more things to weigh
- Thin panels can sag or ripple on a long wall. Ask what thickness you're being quoted and compare it across bids.
- Faded siding is hard to patch. A replacement panel may not match the wall next to it.
- Hard hits in cold weather, like a ball or a rock thrown by a mower, can crack a panel.
So is vinyl right for your house?
Our opinion: vinyl is a fine choice in this climate if it goes over a properly wrapped and flashed wall, and if you wash the shady side once a year. The panels are rarely what fails. The wall behind them is.
If your siding is already showing damage, read repair or replace your siding before you price a full job. The siding page covers what we install and how a re-side goes.
Questions
Can vinyl go right over old wood siding?
Sometimes, but you lose the chance to see rot in the old siding and the sheathing behind it. On any wall that has shown water damage, we'd want the old siding off first.
How often should I wash vinyl siding?
Once a year is plenty for most walls. The shady north side may want it more often. Keep the hose aimed level or down, never up under the laps.
