Can Different Types of Sailcloth Become Moldy?

Precision Sails Mainsail

How Susceptible Is Sailcloth To Mildew?

Once you have invested in a new set of sails you are likely going to want to keep them looking clean, crisp and fresh for as long as possible. A common problem that most of us face if you live in a damp or humid environment. On Ask Precision Sails we had Bob Hudson ask:

“How susceptible is sailcloth to mildew? I am based in the southwest of the UK and it tends to be a bit damp here.”

With two common sail fabrics Dacron and laminate, mildew and mold will show up differently, so let’s take a look at each:


Typically, a Dacron sail is a single sheet of woven material. When a Dacron sail is used as a furling headsail, wrapped tightly in a moist environment, you certainly can experience some mildew due to the limited airflow around the fabric. For this reason, it is advisable if you plan to leave the boat for a large amount of time,  you should consider taking down your sails, ensure they are well dried and store them in out of the weather to prolong their life. Not only will this stop any mold and mildew, but it will also eliminate any unnecessary UV exposure to your sail treads.


Laminate sails come in many shapes and forms. Two common types are ones with clear films on either side and cruising taffeta. Unfortunately, both forms of laminate are at risk of mildew and mold, particularly if there are cracks in the film. Once mildew penetrates the inner layer, it is very difficult to manage and can spread quickly if left to deteriorate.

Again, it is best to dry and store these sails if you plan to take some time off the boat. Just ensure when you are flaking the sails, you take caution not to bend and crack the outer layers when folding too tightly. Often, furling these sails can be a more effective way to store and protect them.

Simply due to the overall cost of laminate, it is advisable to choose Dacron sails for wet or humid environments as they tend to wear better in these environments if adequate care is upheld.

Following this outline, especially in hot and humid conditions, will help keep your boat looking as beautiful as ever. Nobody wants to show off a black, splotchy sail due to improper care. Keep note that salt water dampness will take longer to fully dry rather than freshwater. If you’re sailing out in the open waters and you get some salt water on your sail, be careful and ensure that it fully dries properly to avoid those ugly, black moldy spots.

If you need to clean your sails, we have a blog that outlines how to clean your sails. Visit it here.

Related Posts

Back To The Blog Page
Request a Quote