I know a little about moisture damage. I have lived in both extremely wet environments (Corvallis, Oregon) and extremely dry environments (Santa Fe, New Mexico). I currently live just three blocks from the ocean (Danang, Vietnam). Preventing moisture problems is a big problem and it’s not limited to catamarans.
Preventing moisture damage is necessary in catamarans. Moisture damage is the biggest cause of health problems, property damage and the reason for constant cleaning on a catamaran. Daily activities like living, breathing, cooking, showering and washing clothes all create humidity, which causes moisture damage everywhere it is contained.
In my view, the best approach is to decide which areas of your boat will be open to the breezes and which are contained and controlled. Humidity is the enemy of most organic materials, like fabrics and books. If you live on your boat and you like these things. Consider keeping them in a location where you can control the humidity.
Catamarans, like all boats, spend nearly all their time on or in water. (At least we hope so!) They are highly susceptible to damage from water moisture, which is caused by excess water. That information comes as a big surprise to some people. But it shouldn’t.
These problems come from a variety of sources. And, there are a variety of solutions and ways to prevent it. Most catamarans are made of fiberglass. All boats are made of waterproof materials. These materials are great at keeping the water out. However, this means that they are also great at keeping humidity inside.
Anywhere that humidity is kept inside without air circulation brings potential problems. I will address this damage in a Catamaran, but nearly everything applies to sailboats in general.
In this article I’m going to cover:
- how to know if you have moisture damage
- the causes of moisture damage
- the effects of moisture damage
- how to treat moisture damage
- how to prevent future moisture damage
Let’s dive right into preventing moisture damage in catamarans.
How to Spot Moisture Damage in Catamarans
Moisture damage can be invisible. You may not know you have a problem until it’s too late. Most often this shows up when you are buying or selling a boat. This is when you will need to pay special attention. The first sign of a problem may be the smell. If you are buying or selling a boat, ask a good friend to visit and check. Close the cabin and ask if they smell a problem.
Musty Smell
Mold and mildew often get started in the hidden spaces behind and underneath something else. The first indicator that you have a problem may be the smell. As soon as you step into the frame, the musty smell easily hits your nose. you can easily smell the dampness of objects in the boat, or on the surface of the Catamarans.
Visible Damage
Mold and mildew love humid conditions. Mildew grows in dark, damp places with poor ventilation. In addition, the cabin of a boat is the perfect breeding ground for mold. On the other hand, mildew is less serious than the toxic black mold. However, the musty smell of mildew is a warning sign that moisture is building up, and mold could soon follow. This is clearly something that will soon be obvious, and by then, it may be too late.
Rotten Timber
Moisture may cause rot in reinforcing timbers on kit catamarans. A transom with rot can quickly lose its structural integrity, and also it’s ability to handle the engine thrust. A transom is a necessary part of any hull. Without this, the boat may seriously deteriorate beyond repair. A damaged transom can cause the boat serious problems. Moisture buildup in the cabin of any sailboat is the main cause of damage on many boats, and it can easily destroy the comfort of your Catamaran cabin.
Functional
Electric Corrosion
Moisture is an obvious threat to the electrical systems aboard a Catamaran. Water will causes many problems from contact corrosion to short-circuits, which can be dangerous to the boat structure or human health. If you begin having electrical corrosion, the main cause can be due to moisture.
The Many Causes of Moisture Damage in Catamarans
High Humidity
The most obvious cause of moisture on boats is High humidity because boat is always on water and tropical weather is humid. High humidity in the closed environments are common problems on sailboats. Moisture is a big problem on catamarans, indeed on all sailboats. Prevention is important because problems can spread quickly. Moisture can lead to serious health problems for those living aboard their boats, electrical and structural problems for the boat, which can lower the resale value.
Closed Environments
The inside of windows that are closed during cool weather. Another reason is the closed environment. Usually people living on boats keep their doors closed when the weather is cold or windy. Mildew loves a closed boat. Air trapped inside carries the spores in with the moisture. Unattended boats suffer moisture through condensation because water, air, and hull temperatures are always changing and at different rates. This process is accelerated in a humid climate.
Leaks
Rain can leak in from the deck above. Sea water is not drinkable, so people on boats catch the rain water to drink. Rain also can leak into boats through small holes in the deck of the boat. And water leaking through the deck core can cause mold that rots the deck core. This can remain hidden inside the boat for a long time.
Little ventilation
Another cause of moisture is also limited ventilation of the boat. Some Catamarans have fewer windows or dehumidifiers, heaters, ventilation doors, fans, air conditioners, etc. That makes the air in the boat not well ventilated for a long time, even making the whole boat become susceptible.
Waves
When we sail at sea, waves are often one of the causes of moisture. Splashing waves from traveling by boat have splashed water on the side of the boat, the cabin and the surface of the boat. Salty seawater not only corrodes the surface, but it also causes heavy moisture in your catamaran.
Cool weather
Cool weather means keeping warm means less or no ventilation, which means stagnant air. When air is left standing for long periods of time and not being circulated, it builds up as water vapor, causing moisture in your Catamaran.
Tropical environments look great in photos. What you don’t see are that they are humid like a greenhouse. This environment is great for plants, but not always human friendly. If you are living on a boat, the tropical environment includes thunderstorms and hot air. All of these will make your living place humid.
Condensation
Condensation occurs on all cold hard surfaces, like glass, fiberglass or metal. Condensation is a hidden cause that may be inherent in your boat design. Fiberglass is cold and smooth to the touch, this may be easy to clean, but it may be an ideal surface for moisture to condense from the air and drip into a hidden space.
The main down side of using fiberglass is that the hull cannot “breathe” to let the any moisture out. The same quality that makes metal or fiberglass a good hull by keeping the water out, also has the problem of keeping the inside water – leaks, condensation, splashes and humidity – inside.
In contrast, wood, for example, will allow the humidity inside to migrate outside, and it does not get cold, meaning there is no condensation.
Salty environment
Water consists mostly of water molecules, but it also has low concentrations of H+ ions and OH- ions. The humid, salty air of the ocean contains more water molecules and ion elements than the desert setting, and is thus the better electrolyte. So a salty environment will attract moisture and water than normal environment.
Hulls leak
Hulls do occasionally leak, but this is extremely rare. The combination of moisture, oxygen and salt, in ocean water damages metal worse than rust does. This combination corrodes, or eats away at the metal, weakening it and causing damage that may not be apparent until it fails. Saltwater corrodes metal five times faster than fresh water. The salty, ocean air causes metal to corrode 10 times faster than air with normal humidity. Bacteria in ocean water consumes iron, which turns to rust.
Forms of Moisture Damage in Catamarans
Mold
Mold is a clear sign of moisture. It can be a rude awakening to open your boat and be greeted with a dank, musty smell or an interior full of mildewy cushions, carpets, and headliners. Mold spreads by forming spores, and they are already in the air. Mold also thrives in cooler weather. Even in frigid climates, the interior of a catamaran may reach higher temperatures that can support the growth of mold when the sun is shining.
Mildew
Mildew is the bane of almost every catamaran owner. Mildew is the first beginning stage of mold. These fungi are more than ugly and can do serious damage to your boat if not prevented. It is much easier to prevent the mildew than wait to treat the mold. But even small amounts of mildew can do serious damage to your boat.
Mildew is fast growing, difficult to locate until it has done real damage and almost impossible to remove completely. In addition, mildew has an extremely offensive smell that is noticeable in a closed space that repels many people. Furthermore, mildew is unsightly and difficult to treat.
Rust
Most people are aware that water moisture is the main contributor to the formation of rust. Your boat will spend a tremendous amount of time in the water and that leaves it susceptible to oxidation. Any exposed surface will develop some level of corrosion. This is due to water moisture, especially salt water.
Rust is the dark orange-colored material that grows on iron surfaces. It is the result of the oxidation or corrosion of unpainted metal. Rust weakens the metal and leaves an unsightly stain on most surfaces, especially noticeable on the white surfaces of most boats. As a result, most metal marine hardware is stainless steel, aluminum or coated in chrome.
Rot
Rot is another form of moisture damage. Rot is usually caused by water allowed to remain in hidden areas. Wooden boats are highly susceptible to the process of rot. All wooden surfaces must be sealed against water. Exposure to water on a boat is, well, unavoidable — and wood that has frequent exposure to water is simply asking for the potential for rot.
Corrosion
Corrosion is a result of excess moisture affecting metal, which can cause considerable damage to the exposed metal parts on boats. Boats can suffer from corrosion side-effects to the running gear like other boats kept in the water. The metal fittings start to degrade and the chrome plating starts to bubble.
Effects of Moisture Damage in Catamarans
Boats live in a damp environment, and water moisture inside the boat can cause real trouble when there is inadequate ventilation. The problem is generally worse when boats are stored during the offseason. This is especially when they are not used on the water for long a time. The still air allows mold and mildew to grow in the humid environment. This produces the unpleasant odors and the little black mildew spots of mildew. This ultimately causes seats and other boat fabrics to degrade.
Cosmetic Damage May Hide Serious Problems
Moisture causes a lot of cosmetic damage. Patches and mold corrosion can quickly degrade your catamaran. This makes the appearance of the boat look less luxurious and will cost you a lot of money to repair.
Cosmetic damage may hide more serious problems under the surface. If you seen cosmetic damage, be sure to explore the possibilities of hidden damage. Find the cause of the problem and clean the area. If the problem persists, you should investigate. Often the real damage is invisible and only comes to light when the repair is expensive.
I found this to be true when I lived in Oregon. I noticed a small hole in the wooden floor. This appeared very minor, yet if the floor was soft, I knew this was a bigger problem. By the time we had experts look at the damage from the crawl space under the house, we discovered a large area. This repair cost hundreds of dollars because we caught the leak early. In a few months, the cost would have been in the thousands.
Structural Damage on a Boat is Serious
Moisture may have rot in the reinforcing timber. A transom with rot has lost the ability to handle the force of an engine. A transom is a critical part of the hull. Without this part, the boat may seriously deteriorate. A damaged transom will eventually allow water to enter and may cause your boat to sink. Humidity also causes damaged furniture and clothes in ships.
Corrosion Leads to Electrical Damage
Corrosion leads to damaged electronic equipment, including contacts failing, wires breaking and devices failing. When these wires are connected to your power system, appliances and navigation equipment can fail, malfunction or deliver incorrect information or even be damaged and need to be replaced.
Moisture problems and corrosion of your power wiring can also be dangerous and cause an electrical shock to captains, crews and their guests. This is a relatively low risk on fiberglass boats, but it is a much bigger concern on aluminum hulls and will be an even bigger threat as catamarans upgrade to electric propulsion. Electric propulsion requires higher voltages and moisture damage will become a greater danger.
Health Damage
Moisture causes a lot of problems that are potentially harmful to health. Health problems from excessive moisture and too high humidity include rashes, sinus infections, coughs, respiratory problems, chronic infections and more. Living in a humid environment for a long time causes many respiratory diseases, especially black mold.
How Dangerous is the Worst Mold?
Black mold is usually regarded as the most dangerous. Symptoms includes chronic rashes, chronic fatigue, persistent headaches, irritation to the eyes and mucus membranes of the nose and throat. Some people regard exposure to black mold as potentially lethal.
The growth of mold and bacteria on your food should not be underestimated. Each fruit and vegetable has the potential for growing hidden molds. Normally this is not a big problem because these foods have adequate air flow around them and they get eaten in a short time. However, all of the produce you buy to keep you healthy is an ideal place for molds to grow.
How to Treat Moisture Damage in Catamarans
The experts generally agree that it’s best be cautious about treading mold problems from moisture damage. Mold problems are usually large systemic problems that appear minor at the beginning. Experts usually recommend that you hire professionals.
However, if you tackle this problem yourself, here are the recommendations. Protect yourself with gloves and avoid breathing the mold spores. Reduce the moisture level with ventilation or dehumidifiers. Remove the affected fabric materials and then thoroughly clean the area. Treat the area and surrounding areas with mold inhibitors to prevent future infections.
Can I Remediate Mold Yourself?
Once you have discovered the presence of mold, you might be tempted to clean it up on your own. If the problem is minor, you can tackle it on your own. However, mold remediation is often a bigger job than it first appears and is a task that is better left in the hands of professionals.
How Long Does it Take to Get Sick from Mold Exposure?
Symptoms of mold exposure can appear after only 2 hours after exposure and last for days. These symptoms include shortness of breath, cough, muscle aches, chills, fever, night sweats, and profound fatigue. People may also have shortness of breath and cough, as well as weight loss.
Can Mold Damage be Fixed?
If you are mold-sensitive and the mold problem is severe, consider living elsewhere during cleanup. Remediation costs vary depending on where the mold exists and whether the damage is severe. Costs can very from $2,000 for removing surface mold to $10,000 or more to repair widespread structural damage.
How the Professionals Remove Mold
Mold professionals use HEPA air scrubbers, HEPA vacuums and professional equipment such as commercial-strength dehumidifiers. This is specialized equipment and will likely be expensive. If that’s not possible, open the area to fresh air and sunshine.
Best Commercial Mold Cleaners
There is a company based in Oregon where winter moisture is always a problem. 30secondscleaners makes a popular line of cleaners for mold and related cleaning. Their products kill lichen and moss, and clean stains from algae, mold and mildew. They say their products are safe around lawns and plants.
How Can I Treat Mold Myself?
Bleach is your friend. Scrub the surface mold from walls and trim with a mixture of one part bleach to four parts water. This will kill the mold. Next, use a soft brush and scrub the area until the mold is gone. After scrubbing the surfaces, allow the bleach to to penetrate into the surfaces. This will help to prevent the mold from returning.
How to Prevent Moisture Damage in Catamarans
Passive Ventilation Is Great
Dorade boxes are tubes that ventilate the interior of your boat to the deck. They help circulate the air on your boat passively. Adequate ventilation through your boat’s interior is nearly ideal for preventing moisture buildup. The result is preventing mildew from getting started and thus the associated problems.
You can install passive vents on hatches or on the hull. As the wind blows over the vent outside the boat, interior air is circulated. A boat that is opened up and used frequently seldom has as many moisture problems. There are exceptions, like in very humid environments or when leaks allow rainwater and spray to enter the cabin.
Active Ventilation is Better
Like dorade boxes, solar powered vents are a better solution. Solar-powered dorade vents are becoming popular and are a better solution. These vents have solar cells which charge a small battery that powers an exhaust fan. However, the do have some limitations. They don’t work in the offseason when the boat is closed and covered.
Can I Prevent Moisture Damage with Dehumidifiers
Dehumidifiers are a good prevention for moisture damage because they remove the humid air. There are many types of dehumidifiers available. Household dehumidifiers are a bit more powerful and typically run on AC power. Marine dehumidifiers are available and run on DC power. Both AC and DC power dehumidifiers will fill a container or can be adapted for continuous drain hose. Desiccant dehumidifiers are much cheaper, however, they need constant maintenance.
Dehumidifiers and air conditioners typically draw a relatively high amount of electrical power. Check your power level your system has available, the amperage of the device you are considering and whether you have the inverter capacity for providing AC power.
One of the most recommended dehumidifiers in my experience is the Sharp DW-D20A-W. This is a handsome model and it offers several additional settings such as clothes drying mode and oscillating louvers. The Sharp dehumidifier is a highly recommended dehumidifier for normal household uses. It produces up to 1.59 gal (6 liters) of water per day. It is designed for household use and apparently only runs on AC power.
Do Air Conditioners Prevent Moisture Damage?
Air conditioned air has less humidity and therefore is a good at preventing moisture damage. Air conditioners are cousins to dehumidifiers, and are probably more well-known. Both AC and dehumidifiers operate by forcing air over cold fins and condensing the water moisture. Air is fanned across a cold surface, which precipitates the moisture out of the air. Dehumidifiers generally warm the air, while air conditioners cool it.
Both dehumidifiers and air conditioners drain this moisture as a condensate. It is technically fresh water and you may be tempted to drink it. Don’t. The same molds and problems that are in your boat are also in this water. Drinking this water is much more dangerous than breathing the spores because now those problems are inside.
There is one dehumidifier that includes a reverse osmosis filter. According to the company that markets the Air2Water, this water is drinkable. If your boat does not have a watermaker, this product would be worth considering. It has all of the components of a watermaker, and would have the added benefit of removing the moisture from the air. However, they do not publish any guarantees. I emailed them but they didn’t provide any lab tests.
Does Air2water Help Water Moisture Damage?
Air2Water is a special dehumidifier that produces potable water from the air. According to the manufacturer, the A45 is designed to condense the water from the air with stainless steel collection fins. The water is filtered through a sediment filter then a pre-carbon, post carbon and reverse osmosis filter. There is UV light in both holding tanks. The A45 can capture up to 11.9 gallons (45.05 l) of water per day. Pure drinking water. They have the A45 and A150c in stock and ready to go.
What are Desiccants and Do They Remove Humid Air?
A desiccant is used to induce dryness by absorbing the water moisture in its vicinity. Commercially, desiccants are widely used in industry to control the level of water in gas. However, they are also used in households and boats for fighting mildew. Commonly pre-packaged desiccants are sold for reducing the humidity of the environment.
Commonly designed desiccants are readily available and most are quite inexpensive. They work quietly, passively and without power. They tend to be inert and highly effective in certain circumstances. They have capacity limits and must be recharged frequently. As a result, they have limited uses.
Cat Litter can act as an inexpensive short-term desiccant. Add some ordinary material designed for a cat-box into a fabric container and put it where moisture collects. This material will attract the excess moisture. Regularly put this out in the sunshine or an oven to release the collected moisture to recharge it.
Can Heaters Make a Difference in Moisture Damage?
Hot air has a much higher capacity for holding water moisture. Water condenses primarily because the warmer air becomes cooler. Therefore, heating the air will give it more capacity to hold the water moisture. However, heating with electric is problematic, especially from solar. Gas and diesel fuels also have their problems.
Can Wood Stoves Make a Different on a Boat?
Wood stoves are great for drying the air in cooler climates. The fire sucks the water out of the air and sends it up the chimney with the smoke. I learned this living in the Cascades of Western Oregon. The winter weather was very cold and very humid. However, inside the homes the air was invariably warm and dry and cozy. This was thanks to the abundance of wood and the of wood stoves used for heating.
Wood stoves are safe and useful when used properly. They are relatively inexpensive, not difficult to maintain, driftwood fuel can be free, and they are visually appealing.
However, they must be vented carefully and require maintenance in use. In addition, there are often local regulations regarding their proper use, which should be followed. Catamarans are made of fiberglass, which is flammable and therefore, a potential fire risk. Be extra cautious with fire. Keep a fire extinguisher close and keep it fully charged.
Don’t Use Sea Water on Your Clothes
If you wash clothes in salt water, be sure to rinse them in fresh water. Clothes washed in salt water, will have a residue of salt in the clothing. This salt from the ocean water acts as a desiccant and attracts water back into your freshly washed clothes. As a result, you will have to wash them very frequently, which will age your clothes.
Fully drying your clothing, especially after washing your clothes is important. Remember to dry your clothes soon after washing. If you store your clothing in closed spaces, it’s recommended that you include some type of device to lower the humidity and keep them from attracting moisture. This can be your choice of a desiccant, an air conditioner or dehumidifier.
This won’t usually be a problem if you are fortunate enough to have a clothes dryer. However, if you don’t, you will want to time washing your clothes in synch with the weather report rather than the calendar. This will ensure that you have adequate sunshine to fully dry your clothes after washing.
Conclusions
In this article, I have covered:
- How to Know if You Have Moisture Damage
If you live on the water, you live with the constant potential for water moisture damage. You live in an area of high humidity all the time. Any spaces where the air doesn’t circulate well are potential problems for mold spores to grow and cleaning all areas is recommended. You most certainly can find potential problems.
- The Causes of Moisture Damage
Excess water moisture is a constant issue on any boat. In addition, there are multiple sources of water entering the hidden spaces of your catamaran. Moisture damage is not only ugly in appearance, it can be very expensive to clean, is definitely unhealthy and can be very costly to repair. Besides, it is the biggest factor in lowering your property value.
- The Effects of Moisture Damage
The effects of constant high humidity include serious health problems, cause hidden damage to your catamaran until the problem is wide-spread, loss of property value and costly repairs. There are lots of ways to handle moisture damage in catamarans.
- How to Treat Moisture Damage
There are several treatments for the problems from moisture damage, including commercial products and less expensive household products.
- How to Prevent Future Moisture Damage
Preventing future moisture damage is the least costly and most effective way to care for your property.
Air circulation is the cheapest and most enjoyable way to prevent problems from moisture damage. This is what greenhouses do and it works well for them even though they have near one hundred percent humidity to care for their plants. Passive air circulation is essential to preventing mold growth. Assisting the air circulation with active solar fans is better.
The second easiest way to prevent mold growth is cleaning the surfaces. Fortunately, fiberglass is one easy surface to clean. Cleaning every surface of your catamaran on a regular basis is key to preventing the growth of problems. The frequency of cleaning is up to you, but the regular schedule that includes every surface is what’s important.
Heating your catamaran is an excellent way to prevent future problems in cooler climates. Warmer air holds more water moisture, which means it doesn’t condense on the surfaces and cause problems.
I hope this has answered your questions. Please leave me feedback if you have further questions.
Sources:
https://30secondscleaners.com/
https://www.clorox.com/learn/does-bleach-kill-mold/
https://dustfreedom.com/product/dw-d20a-w-50m%C2%B2/