Shutters for humid rooms: bathrooms, the window over the kitchen sink, and laundry rooms (2027)

Updated October 22, 2026

The short answer: a humid room isn’t the problem. Water landing on the shutter is. Painted poplar works in a ventilated bathroom, beside most kitchen sinks and in most laundry rooms. The window in the shower spray is the exception, and that’s the room our aluminum interior shutters, coming in 2027, are designed for.

Humidity and water are different problems

Wood is hygroscopic: it takes on moisture from the air around it and gives it back, and how much depends on the air’s relative humidity and temperature^[4]. The US Forest Products Laboratory’s handbook puts it plainly: many of the challenges of using wood come from changes in its moisture content, or from too much moisture in the wood^[4]. Paint slows that exchange; it doesn’t stop it.

That gives you the test for any room. If the air gets damp for half an hour and then dries, a painted wood shutter swells a little and settles back, exactly like the painted bathroom door beside it. If liquid water reaches the wood again and again (shower spray, a splashing faucet, a window that streams with condensation every winter morning), the paint is the only thing between water and bare wood, and paint gets nicked. That’s when wood shutters crack at the joints, swell louvers tight or lose paint along the bottom rail.

Natural Resources Canada notes that condensation is more likely in humid areas such as the kitchen, the bathroom and some basements^[3]. So the three rooms in this guide are the three where the difference matters.

Keep the room in range first

The covering is the second decision. The first is the air. Health Canada recommends keeping indoor relative humidity between 30% and 50%^[1]; the US EPA gives 30% to 60%^[2]. An inexpensive hygrometer on the bathroom shelf tells you which side of that you’re on.

• Bathroom: Health Canada’s advice is to keep the exhaust fan running for at least 30 minutes after a shower or bath^[1]. The EPA says to vent bathrooms to the outside^[2]. A fan that vents into the attic, or doesn’t move air at all, leaves the moisture in the house.
• Kitchen: always use the range hood when cooking, preferably on the highest setting^[1]. A pot of pasta puts a lot of water in the air right beside the window.
• Laundry: hanging wet laundry indoors raises the humidity, and the dryer should vent to the outside^[1][2].

Get those right and wood shutters have an easy life in all three rooms. Get them wrong and no window covering will fix the room; you’ll see it on the paint, the drywall and the glass first.

Which shutter for which window

The aluminum line isn’t priced or on sale yet. The table describes what it’s designed for; where a claim depends on the supplier’s test results, we’ll say so until we have them.

Bathrooms: the fan decides

Most bathroom windows sit beside the tub, over the toilet or above a vanity, a few feet from the shower. In that spot a painted poplar shutter sees steam, not spray. The routine that keeps it looking new takes a minute: fan on during the shower and for 30 minutes after, louvers tilted open afterwards so air moves between the panel and the glass, and a dry cloth over anything that beads on the wood. Our bathroom shutters page has the layouts that work in bathrooms, including café-style panels that cover the lower half for privacy and leave the top open to light.

Closing the louvers tight on a cold winter night and leaving them shut through the morning shower is the one habit to avoid. Health Canada warns that heavy curtains or blinds can trap the cold and moisture and cause condensation on windows, and recommends keeping coverings open so warm air reaches the glass^[1]. A closed shutter does the same thing. Open the louvers once the room has light; you keep the privacy at most angles and the glass stays warmer.

The window in the shower

Neither our painted poplar nor our 2027 aluminum line belongs in direct shower spray today. Wood shouldn’t be there, and we won’t recommend the aluminum shutters for spray until the supplier’s water test is on file. If you’re doing that bathroom now, a vinyl shutter sold for wet use, frosted glass or a privacy film are the honest options, and we’d rather tell you that than sell you a shutter that fails.

The window over the kitchen sink

This is the window people most often ask about, and it has three problems the bathroom doesn’t.

Splash. Water from the faucet, the sprayer and the dish rack lands on the bottom rail and the lowest louvers. A painted shutter handles it if you wipe it off. A shutter that stays wet along the bottom rail day after day is the one that loses its paint there first.

Reach. You lean over the sink to tilt the louvers or open a panel, so make the controls easy. A front tilt rod is the easiest to reach; hidden tilt (no rod) means you tilt by moving a louver, which is tidy but means touching the louvers with wet hands. Both are options in the designer.

Faucet clearance. An inside-mounted hinged panel swings out into the room about as far as it is wide. A tall gooseneck faucet can stop it opening. Measure from the face of the window frame to the faucet, then choose narrower panels, a café shutter on the lower half only, or tier-on-tier panels so only the top pair needs to open. Add the faucet clearance to the window’s notes and we’ll check it before we build. The inside vs outside mount guide covers measuring to the first thing that sticks out.

Cooking steam is the smaller issue. Use the range hood^[1] and the kitchen stays in range for wood. Where the sink splashes hard (a deep single basin under the window, a pull-down sprayer used all day), the aluminum interior shutters are the lower-upkeep choice once they launch: aluminum doesn’t rust the way steel does. A thin oxide film forms on its surface and reseals itself if it’s scratched.

Laundry rooms

A laundry room with the dryer vented outside is a dry room most of the time, and painted wood is fine. Check the vent once: Health Canada and the EPA both say the dryer should vent to the outside^[1][2], and a disconnected hose behind the machine puts warm, wet air straight into the room.

Racks of clothes drying indoors are a different load. Health Canada notes that hanging wet laundry indoors raises indoor humidity^[1]. If that’s your routine, watch the hygrometer. If it stays above 50% for hours at a time, or the window streams in winter, choose the aluminum line for that room, or run a dehumidifier and stay with wood. A laundry room in the basement has the basement’s conditions on top of the washer’s, which our basement window guide covers.

What the 2027 aluminum line is, and what we can say about it yet

Our aluminum interior shutters are movable-louver shutters with a wood finish, offered with moulding levels 1 to 3 like our wood shutters. An aluminum frame and louvers in place of solid wood. A finish chosen to stand up to sun and humidity, on a shutter designed for the inside. Aluminum doesn’t rust the way steel does. A thin oxide film forms on its surface and reseals itself if it’s scratched.

We’re being careful about the claims. The line is coming in 2027, it isn’t priced, and we don’t yet have the supplier’s full spec sheet. Claims that depend on test results, such as how it handles direct water, an exact weight against our poplar panel, or the standard the finish meets, will appear here when we can show the document behind them. The aluminum shutters page has the waitlist.

Finishing and care in humid rooms

• Seal bare wood. If you repaint, sand out a chip or drill a new hole for a magnet catch, prime and paint the bare wood before the room gets steamy again; exposed wood is where water gets in.
• Wipe, don’t soak. A damp microfibre cloth and a dry one after. No spray cleaner aimed at the louvers, and no water left in the louver pins. The care guide has the details.
• Open after use. Tilt the louvers open after a shower or a load of laundry so the back of the panel dries as fast as the front.
• Watch the bottom rail. It’s where water collects first. A chip there is worth touching up the same week.
• Don’t seal the panel to the glass. Leave the gap the frame gives you; air needs to move behind the shutter.

If you’re weighing up materials beyond these two, our wood vs vinyl and window condensation guides go further.