You’ve just spent the winter dreaming about taking your pontoon boat back onto the water for the summer months, remove your boat cover, step up onto the deck and are horrified by those red or black stains that have appeared all over the carpet. This recently happened to me so I did some research online, as I had never had to deal with black stains in the carpet before, this is what I found out, and you can scroll down for the exact cleaning method.

Using cheap dish soap, 2 buckets, some warm water, and a sponge, it’s possible to clean black stains out of a pontoon boat carpet. For more stubborn stains, I would recommend using a power washer.

There’s nothing worse than black stains is there? Well perhaps there is, and that would be if pests and mice have got into the boat during the winter – here’s how you can protect from pest damage by the way.

But back to the original problem of how to get black stains out of a pontoon boat carpet.

How do you do it? It’s simple, and I will tell you how you can do it in super quick time, and just by using everyday household items that you should already have available to hand… but first up here’s what you’re going to need in order to do a proper clean-up operation.

What You Need for the Job

  • Dawn Dish Soap (buy on Amazon)
  • 2 Buckets or 2 Bowls
  • Warm Water
  • Bleach
  • Cloth or Sponge

Cleaning Instructions

Before you even consider using bleach, which is very much a last resort, you should test using the Dawn dish soap mixed in your bucket with some warm water. In most cases, and with smaller black stains this should suffice.

All that you do is soak the black stains on the carpet with the water and soap mix and then leave it for 5 minutes. After 5 minutes, then rinse over the area with a warm and clean water mix.

You might also need to do a little rubbing with a cloth or sponge. Don’t use any color based cloths, as you don’t want the cloth color to come off on the carpet. Also, don’t use paper towels as these tend to leave paper debris on the pontoon carpet which can also be annoyingly hard to get back up. If you have ever cleaned carpet at home with a paper towel you will know what I mean.

If this cleaning process has not got the black stains or red stains out of your pontoon carpet, then it’s time to move onto the bleach solution. But please, proceed with caution as you don’t want to damage the carpet at all or leave marks on it that won’t shift.

My tried and tested method with bleach means that you will have to mix up one quarter bleach into one gallon of warm water in your bucket or bowl and follow the same steps as described above, but with one key difference: an initial test area or patch.

As I said, proceed with a little caution here, but don’t worry too much. Most pontoon boat carpet is manufactured from a synthetic UV polypropylene fiber material which won’t have been solution dyed and so won’t react badly to bleach.

Because of this, it should stand up absolutely fine to being cleaned with a bleach-based water solution, but you will want to test it out first.

If you don’t know if your pontoon boat carpet is made from synthetic, non-dyed material, then test a small patch with your bleach-based cleaning solution first. When I did this for the first time, I tested out a piece of carpet underneath some of my seating just to check I wasn’t going to leave any lasting damage or marks.

If your test is successful, you can repeat the process on the area where the black stains and mold is – but be even more diligent when it comes to the rinsing through process once you have left the solution on for 5 minutes.

Update: Since writing this guide, I have been contacted by another pontooner who wanted to impart his tips on removing black stains from the pontoon carpet. I thought it would be useful to include his valuable advice too which I have condensed into some notes below.

Use a Power Washer for Extensive Black Stains

I like to spray the area with a small water spray bottle, I find that this works really well on the black stains. But for the best results, in particular if there are very large black mold stains is to use a power washer – the one I have is the Sun Joe SPX4000 power washer.

I power wash the entire pontoon carpet floor and then let it dry out in the sunshine before possibly doing it again if needed.

Because I use a power washer on the black stains, I do end up really soaking the entire carpet, so it can be tricky do get it completely dry. There is a solution though, which is to take the boat off the trailer and then crank the stand downward, so it goes as low as it can.

By doing this, nature will take over, and the water will drain off towards the boat’s front. And if it’s a sunny day, it will dry off even quicker.

If you are unlucky enough to not have a sunny day, then you hire a large blower unit which you can then place at the back of the boat so that it blows forwards. The type I mean are the industrial ones you might find on a construction site – click here to view pictures of what I mean.

After around 3 to 4 hours then entire carpet will not just be free of black stains but will also be as a dry as a bone.


So, there you have it!

Wave goodbye to black stains on your pontoon carpet forever with this handy guide. I trust it will work for you, as for me it’s been an absolute dream of a solution when it comes to cleaning off that annoying mold.

If you do have a better solution or would like to offer any feedback on this carpet cleaning solution then I would love to hear from you on the usual channels.

Whilst Pontoonopedia is my baby, I do love to also have the input from other pontoon boat owners out there, as there is always more than one way to skin a cat!

PS: You might need to replace the entire carpet with a new one, if the existing one is beyond repair. Find out how to replace a pontoon boat carpet in this additional guide I recently published.