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How to Fiberglass a Boat Floor

how to fiberglass a boat floor

Fiberglassing is a common way to waterproof and protect boats. It is also a good way to repair damaged sections of boats. This method can be used on many different types of boats, including inflatables, canoes, kayaks, and small sailboats.

As flooring is important to ensure safety and provide a quality experience with your boat, fiberglass can be an excellent material. Read on to know how to fiberglass your boat floor and make the best out of it.

How to Fiberglass your Boat Floor

To fiberglass a boat floor, you will need the following materials:

  • Epoxy resin
  • Fiberglass mats
  • Rolling pin
  • Plastic sheeting
  • Paintbrush
  • Masking tape
  • A measuring tape and a marker
  • Utility knife
  • Sandpaper
  • New plywood pieces, screws, and adhesives (if replacement is required)
  • A pair of glasses and a mask

Step 1: Remove the Old Flooring

As you repair your flooring, there might be damaged parts that need to be fixed before fiberglass application. In that case, you can sand the surface and use sealant to improve the parts so they are smooth again.

If the floor already feels too soft, making it unstable and unsafe for use, you need to replace it with new plywood pieces. This process will take several hours, including removing the old ones and then measuring and installing the new ones with screws, nails, and adhesive.

Step 2: Check and Replace the Stringers if Necessary

As we want to address all issues related to the flooring so the new fiberglass coat can last for a long time, it is recommended to check the stringers for any damage.

If they are still good from your last installation, carry on with fiberglassing. If not, you should change them right away as they hold your boat flooring. You risk throwing away all the effort of replacing plywood floors and fiberglass if you do not.

Step 3: Prepare the Area

Now it’s time to start fiberglassing when the stringers and plywood floor are ready. The first step is to prepare the area where you will be working.

You will need to lay down some plastic sheeting to protect the floor and any nearby surfaces from the epoxy resin. Once the area is protected, use the masking tape to mark off the section of the floor that you will be working on.

Step 4: Cut the Fiberglass Mats

Next, measure the floor space with your measuring tape, and use a marker to identify the cut. Now, you can use the utility knife to cut the fiberglass mats into pieces that will fit over the section of the floor you are working on.

Make sure that each piece of the carpet overlaps with the other pieces so that there are no gaps.

Step 5: Mix the Epoxy Resin

Now it’s time to mix the epoxy resin according to the manufacturer’s instructions. Make sure to pay attention to the drying time, as you do not want to wait too long before attaching the carpets onto the floor.

Once it is mixed, pour it over the section of the floor you are working on so it is on all tricky corners. You risk having the fiberglass mats peeled off if the resin is not distributed evenly.

Step 6: Apply the Fiberglass Carpets

You can place the cut fiberglass mats onto the areas with resin. Using the paintbrush, apply the fiberglass cloth to the wet epoxy resin. Make sure that each piece of cloth is saturated with resin.

Once all of the pieces of cloth are in place, use the rolling pin to roll out any air bubbles that might be trapped under the cloth.

Step 7: Let it Cure

Now all you have to do is let the epoxy cure according to the manufacturer’s instructions. Once it is cured, your boat floor will be stronger and more waterproof than ever before!

Additional Tips and Advice

how many layers of fiberglass for boat floor

  • If you are working on an inflatable boat, make sure that the epoxy is completely cured before you inflate the boat
  • Otherwise, the pressure from the air inside the boat could cause the epoxy to crack
  • If you are working on a wooden boat, be sure to sand down the floor before you start fiberglassing. This will help the epoxy to better adhere to the wood
  • Fiberglassing is a messy job, so be sure to wear old clothes that you don’t mind getting ruined
  • Whenever you are working with epoxy, be sure to work in a well-ventilated area. The fumes from the resin can be dangerous if inhaled for too long

How many Layers of Fiberglass for Boat Floor

Having the right number of layers of fiberglass is vital for your boat floor.

Too few layers will make the floor weak and prone to damage, while too many layers will make it excessively heavy.

Most boat floors are made with a plywood subfloor covered in fiberglass. Many times, the plywood is glued directly to the hull.

The fiberglass is then glued to the plywood and set until the resin cures. The number of layers you’ll need depends on the thickness of your plywood.

  • If you’re using 1/2-inch plywood, you’ll need two layers of fiberglass cloth
  • If you’re using 3/4-inch plywood, you’ll need three layers of cloth


Applying fiberglass resin to a boat floor can be a great way to protect and reinforce the surface. However, it’s important to take your time with the project to ensure that you achieve the best results.

We hope this guide has helped provide some useful information on how to fiberglass a boat floor. Have you tried this project before? What tips would you add? Let us know in the comments below.

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