See full version: Preventing Mold and Mildew
Another way of lowering humidity in a confined space is with chemical dehumidifiers, which use calcium chloride to absorb moisture and then direct it to holding containers. These tubs and bags are safe, inexpensive, easy to put into lockers or other places where removing humidity is a problem, and available at most marine stores. Depending on the amount of humidity, a couple of packets might last all winter; use more for a larger boat.
A single water leak can start spores growing. Rain leaking through hatches and portlights will make a boat's interior a mold haven, so the first thing to do is find and seal leaks. Portlights and windows are probably the primary leak spots on a boat, followed by loose stanchions. On sailboats, chainplates that penetrate the deck are a common problem area, as are deck-stepped masts. Leaking deck hardware (cleats, rails, and windlasses) is another common problem.
Mold loves a closed boat. Air trapped inside holds moisture on which mold thrives. Unattended boats generate moisture inside through condensation because water, air, and hull temperatures are always changing and at different rates. This process accelerates in a humid climate. The solution is to exchange inside air for outside air, which greatly reduces the chance of mold forming. Dorades, louvers, vent plates, and other waterproof ventilation systems help with air circulation. But if there's no air movement in the boat, they won't be effective; powered ventilation might be required. There are 12-volt vents for boats, but unless you can count on a constant supply of electricity, solar-powered vents are a better choice and can move a surprising amount of air. Some models with batteries can run for 24 hours a day, using stored power to run at night. A good rule of thumb is to replace the air inside the boat every hour, and vents are typically rated by how much air they can move in an hour; a 30-foot boat, for example, contains about 800 cubic feet of air. Larger boats typically need two powered vents, one for intake, one for exhaust. here
Clogged cockpit scuppers can lead to a flood of water down below — just what mold needs to grow. (Photo: BoatUS files)
It's easier to prevent mold and mildew than to stop it. Mold is accelerated by warmth and high humidity and, once formed, can survive for years, even if conditions change. And as anyone who's waited too long to clean out a refrigerator can attest, mold also thrives in cooler weather. Even in frigid climates, the interior of a boat can reach temperatures that will support mold when the sun shines on the hull and in the early days of spring.
Most boat insurance policies (including BoatUS/GEICO Marine) typically don't cover mold damage. So it can be a rude awakening to open your boat in the spring and be greeted with a dank, musty smell or an interior full of mildewy cushions, carpets, and headliners. Mold spreads by forming spores, and every boat already has them. The key is to deny them what they want so they can't grow.
Proper boat storage isn’t as simple as it seems, though. Whenever water damage is involved, there’s always a chance for mold growth. The last thing you want is to take your boat out of storage next year only to discover serious mold growth.
In case of mold on your boat, call our business to efficiently remove mold from your property. Our technicians will eliminate all mold and replace damaged property, so the chances of mold growing back after professional removal are slim. Exposure to mold has health risks, so the safest way to remove it is by calling a professional mold removal service who have the proper equipment and cleaning products.
Before the cold weather arrives, there are several maintenance tasks you’ll want to do. For one, put fresh oil in the boat. During the summer, water or acid may have gotten into the oil and it can corrode the boat’s engine. [links]
Once your boat is out of the water for the season, make sure all the water is out too. To prevent boat mold both the interior and exterior must be kept as dry as possible, at all times. This means draining the bilge, if necessary, as well as tracking down any pools or small puddles of water that might be inside the hull. Any time you might have to spend drying out the boat will be repaid by hours not required to clean up mold in the spring.
Far from being unavoidable, boat mold is something that can easily be controlled as long as you take the right steps before storing your vessel.
Ventilation is such an important part of mold prevention that you may want to consider adding one or more small fans inside the hull in order to keep air moving and eliminate moisture completely. Combined with a vented cover, a small fan (or two, for larger boats) will circulate air just enough to prevent mold from forming on any interior or exterior surface. [links]
It is important to inspect your boat pre and post season for the first signs of mildew/mold. It is best treated when you catch it early! Brenda, our resident canvas expert, has a few tips to help you prepare your boat this fall to prevent problems in the spring:
Need more advice? Our team including Brenda is always ready help. Feel free to stop in at the Marina’s canvas shop anytime!
Cover it! Brenda also suggests using a “winter only” cover for your boat. Buying a tarp, having it shrinkwrapped, or putting it inside is essential. We drive by many boats in the winter with only their “summer canvas” on. The moisture seeps through these and get stretched by snow and ice loads. Your regular cover should be removed and stored dry to protect it. The additional canvas should be a bit larger than the one you already have and fit over the sides of the boat. It should be supported by a frame, and then secure it with straps or rope for a tight fit. [links]