How To Fiberglass A Boat Floor? (A Complete Guide)

how to fiberglass a boat floor

A shiny and long-lasting boat floor is what everyone desires to have. Thus they invest in buying top-quality and durable boat floorings. But is it enough? No. To ensure the protection, longevity, and best condition of the boat flooring, fiberglassing is required. No matter which flooring you install, fiberglass matting is not something you can miss out on. 

In making a boat floor, fiberglass is one of the most important components. Fiberglass simply reinforces the boat flooring improving its quality, water resistance, and overall enhances the boat flooring. Besides that, you can choose only fiberglass to cover and make the floor boating. So you see, though we know that fiberglassing a boat floor is beneficial, there is a lot more to learn, right? 

To help you know the process of fiberglassing and other relevant information, I am here with this article. I believe you can make an informed decision after reading this article. With that hope, let’s dive deeper into the matter and know how to fiberglass a boat floor!

4 DIY Steps To Fiberglass A Boat Floor: A Step-by-step Guide

Fiberglass matting on a boat flooring is not really a difficult task. With the right set of tools and guidance, you can accomplish the project. However, a general DIY may not want to do such a hectic task. Do this project only if you know how to work with the tools, and have the basic idea about a boat structure, making, etc. 

Fiberglass flooring on a boat deck can be installed in some simple steps. Follow the steps mentioned below, and get your job done in the simplest way possible: 

Step 1: Change Or Repair The Old Boat Flooring

To lay a fiberglass mat on the boat deck, the first step is to treat the previous boat flooring. To do so, you can change the entire boat flooring if it is severely damaged. If not, you can choose to repair the area that is worn out, has broken, or cracked. 

If you have a broken section on the plywood boat flooring, you can replace the plank and install a new plywood plank. In case of cracks, you may need to change the entire section. Else, you may glue it, or nail it to repair the area. Worn-out areas can be fixed by sanding and sealing. 

Depending on the condition of the boat flooring, you can choose what to do. Make sure that you correct all the errors before fiberglassing the boat flooring. 

Caution: You may need to remove the machines and cables from beneath the boat flooring during the project. If you have no expert with you, take note of the machines and connections you are taking out so that you can reinstall them properly after the project ends. 

Step 2: Work On The Stringers

Changing or replacing the stringer has no direct connection with installing the fiberglass flooring. But this is probably the best opportunity to fix the issue in the boat stringers. As these stringers hold the boat flooring, you must ensure that they are not faulty. 

Now as you are already working on the flooring, this is the best chance to repair the damages in the stringers at the same time. So, look for any damages in the boat stringers and repair or replace them as per necessity. 

Step 3: Install The New Boat Deck

Now that all the repairing and replacements have been done, you can install the new boat deck. Take the measurement of the deck and the sideways of the hull where you will be installing the deck. Depending on the material being used, you have to cut and shape the flooring. Though most floorings are boards or sheets, some may use them as planks or sections. Accordingly, shape the flooring

Now either replace the damaged sections or install new flooring on the boat deck. Nail or glue the flooring strongly to the frame. Now the deck is ready for fiberglass matting.

Step 4: Install The Fiberglass Sheets

After the flooring has been installed, you have to lay the fiberglass sheet evenly on the flooring. Make sure that the sheet doesn’t form any wrinkles on the boat floor. Lay it properly and then seal it with a top-notch sealant. The sealant is necessary so that the fiberglass sheet sits well on the boat flooring. Let the sealant and fiberglass mat sit on the flooring for a day. 

A shielded and long-lasting fiberglass boat flooring is now ready to use!

Why Is Fiberglassing A Boat Floor Necessary? 

Now you may ask why at all you should fiberglass a boat floor. This is a genuine question. Many may think while they are installing a top-notch floor, why is it necessary to fiberglass it?

There are certain reasons why you should fiberglass a boat flooring. Hence, before you choose to have a fiberglass boat, you need to know why fiberglassing a boat floor is necessary. 

The very basic reason why you should fiberglass a boat is to protect the flooring. Though most boat floorings are water-resistant, long exposure to water can damage the flooring. It can rot away the weak areas, eat up some sections, encourage the growth of germs and pests, and reduce the longevity of the flooring. 

Due to exposure to extreme conditions like low temperature, rain, UV light, etc. the boat flooring may discolor, crack, swell, or break under high impact. In such conditions, the fiberglassing protects the flooring. The fiberglass mat with the sealant reinforces the flooring and fairly prevents the flooring from damage. 

This is the main reason why fiber glassing is necessary on boat flooring. It is to increase the life and durability of the boat flooring. 

Advantages Of Fiberglass Boat Floor: Know Why To Choose

There are a few reasons why fiberglass boat flooring is preferred by people. Though not always the best option, at least for floor protection, fiberglass boat flooring is quite a reasonable option.

So before you choose it, let me note the reasons why you fiberglassing a boat floor is a fair option: 

Ease of Cleaning And Maintaining: 

Once you install fiberglass on the floor, maintenance becomes easier. For instance, cleaning and maintaining wood or aluminum flooring would have been difficult as well as expensive. You can minimize the maintenance cost by installing a layer of fiberglass on it. 

In terms of cleaning and maintaining, fiberglass boat flooring is a good option. 

Smooth Flooring: 

Fiberglass flooring is extremely smooth with great finishing. The appearance of the flooring remains intact as the fiberglass flooring protects the layer beneath it. The finish of the fiberglass mat is sleek and smooth as it settles excellently on the flooring. 

So if you want smooth and neat flooring, fiberglassing the boat floor is mandatory. 

Cancels Noise: 

You may have noticed that wooden and aluminum boat floors create noise. While walking on the deck of splashes of water on the deck, most floorings make noise. In fact, the engine noise is doubled with these floorings. But just by installing a layer of fiberglass, you can considerably minimize the noise. 

To make the flooring more comfortable and cancel the unnecessary extreme noises, you should consider having fiberglass flooring. 

Comfort Factor:

If you are considering the comfort of the boat flooring, you must go for fiberglass flooring. This is because fiberglass is extremely smooth and silky. You can have a comfortable walk on the deck and your guests would absolutely love it. So if comfort is a factor to you, you should fiberglass the boat deck. 

To sum up, you have quite good reasons to fiberglass the boat flooring despite increasing the longevity of the boat flooring. Right? 

Aluminum Vs Fiberglass Boat Floor: Which One Is Better? 

This comparison always comes up when discussing fiberglass boat flooring. Aluminum is quite a popular boat flooring option in the market. So why would someone choose fiberglass boat flooring? In fact, the bigger question is whether to choose fiberglass flooring or not?

I have already mentioned a few reasons why you should fiberglass a boat flooring. But when compared to aluminum boat flooring, fiberglass flooring doesn’t get the priority. However, what I want to suggest is that you can fiberglass an aluminum boat flooring. Why? Because it reinforces the flooring and you can enjoy the benefit of both aluminum and fiberglass boat flooring. Sounds amazing, right?

But still, let’s have a look at the comparison chart in case you are confused between aluminum and fiberglass boat flooring: 

DurabilityMore durableLess durable
Ease of maintenanceDifficult to maintainEasy maintenance
StabilityModerately stableMore stable
Corrosion resistanceLess corrosion resistantMore corrosion resistant
Water resistanceModerately water resistantExcellent water resistance
Fire resistanceFairly fire resistanceNot fire resistant
LongevityMore longevityLess longevity
AppearanceDecentExcellent and smooth
SpeedMore speedLess speed
Repairing easeEasyDifficult

Now that you know the basic differences, I hope you can choose which flooring option is better. The preference completely depends on your demands and requirements. But both are good options. And the option is to fiberglass and aluminum flooring if you want the benefits of both the options. 

How Many Layers of Fiberglass For The Boat Floor?

The number of layers of fiberglass for a boat floor repair can vary depending on factors like the level of damage, the desired strength, and the type of boat. Typically, for a standard boat floor repair, you may use at least two to three layers of fiberglass. 

The first layer is often applied directly to the hull’s surface, followed by a layer over the marine-grade plywood. Additional layers can be added as needed for reinforcement, with each layer being saturated in epoxy resin and allowed to cure before adding the next. 

Sanding between layers ensures a smooth and strong bond. The exact number of layers should be determined by the specific repair requirements and the recommendations of the epoxy and fiberglass product manufacturers.

How to Fix a Fiberglass Boat Floor?

Repairing a damaged fiberglass boat floor is a methodical process that starts with a careful assessment of the damage’s extent. Whether replacing the entire floor or specific sections, it’s essential to maintain the boat’s structural integrity throughout. After the damaged sections are removed, the exposed area must be thoroughly cleaned and sanded to provide a suitable surface for repairs. Marine-grade plywood, coated with epoxy resin on both sides to prevent moisture penetration, is then custom-cut and fitted into place. Secure the new sections with epoxy resin and fiberglass mat or cloth, adding more resin for reinforcement. Sanding between layers ensures a smooth finish, and the reinstallation of fixtures completes the repair, resulting in a robust and water-resistant boat floor.

How to Put a Floor in a Fiberglass Boat?

Installing a floor in a fiberglass boat is a meticulous process that starts with clearing the boat of any obstructions and ensuring the hull is free from damage. Marine-grade plywood, cut to match the boat’s dimensions, is then sealed with epoxy resin to make it moisture-resistant. 

The fiberglass mat or cloth is laid onto the boat’s surface, ensuring a smooth fit and saturation with epoxy resin to create a secure bond. Additional layers of resin and fiberglass are added, each curing fully before proceeding. 

Between layers, sanding is essential to achieve a smooth, even finish. After the final layer cures, the reinstallation of fixtures and components completes the process, resulting in a robust and waterproof boat floor fiberglass

How to Replace The Floor in a Fiberglass Boat?

Replacing the floor in a fiberglass boat is a substantial undertaking, demanding careful planning and execution. The process begins with a thorough inspection of the existing floor, assessing the extent of damage. If a full replacement is necessary, the old floor should be methodically removed, taking care to preserve the boat’s structural integrity.

Preparing the surface is crucial, involving cleaning and sanding to create a suitable foundation. Marine-grade plywood, properly sealed with epoxy resin, is then custom-cut and fitted to the boat’s floor. 

The new floor is secured using epoxy resin and fiberglass mat or cloth to ensure a waterproof and robust structure. Additional layers of resin are applied, with curing time between each. Finally, fixtures and components are reinstalled, resulting in a sturdy and long-lasting boat floor.

How to Install a Fiberglass Floor in a Boat?

Installing a fiberglass floor in a boat is a comprehensive process that begins with thorough preparation. Carefully remove the existing flooring, ensuring that the boat’s structural components are in good condition and free of any damage. 

Next, cut marine-grade plywood to fit the floor’s shape and coat it with epoxy resin, sealing it against moisture. Over the wet resin layer, lay fiberglass mat or cloth, ensuring it’s free of air bubbles. Apply multiple layers of epoxy resin, allowing each one to cure before adding the next. 

After the resin has dried, sand the surface for a smooth finish, and consider adding a non-slip coating for safety. Finally, reinstall any fixtures like seats and consoles to complete the project, resulting in a durable and waterproof boat floor.

Frequently Asked Questions: 

How Many Layers Of Fiberglass Do You Need For Your Boat Floor? 

Though we know that fiberglassing a boat flooring is beneficial, to get the best results, you must know the number of layers you should lay on the floor.

You should install at least two layers of fiberglass sheets on the boat flooring to reinforce the deck. If possible, you can add one or two additional layers of fiberglass matting on the deck flooring.

These shields are protecting it from extreme conditions. Note that you should provide enough time to let the sheets settle down. This strengthens the flooring and makes it long-lasting. 

How Much Fiberglass Do You Need For A Boat Flooring? 

Many people are confused about the amount of fiberglass needed to cover a boat deck. Though you can ask that of the seller, you should have a basic idea. 

Ideally, around 8 pounds of fiberglass sheet is enough to lay a single layer of mat on the deck. Now if you want another layer of fiberglass mat, add another 8-pound fiberglass.

If you are willing to lay three or four layers of fiberglass sheets, you can also go for 6-pound fiberglass sheets. These are the minimum amount to strengthen the layer of fiberglass boat floor. 

Is Fiberglass Cloth Or Mat Stronger For Boat Flooring? 

Fiberglass sheets are available in different forms. This is why the confusion appears about which form is the best to install on boat flooring. 

The bonding in a fiberglass cloth is stronger than the bonding in a fiberglass mat. The threads are perpetual in a fiberglass cloth building a dense and compact structure. On the other hand, fiberglass mats have threads running in multiple directions making the bonding looser than the cloth. 

Can You Lay Fiberglass Over Plywood Boat Floor? 

Fiberglass can be used to cover plywood boat floors. In fact, this is commonly done to reinforce the plywood flooring.

Though installing fiberglass over plywood boat flooring is difficult, people still choose to do it with the help of professionals. As plywood is only partially waterproof, fiberglassing is necessary.

It strengthens the plywood flooring, makes it water-resistant, and improves the longevity of the boat flooring. Therefore, you can consider installing fiberglass over the plywood boat floor. 

Do You Have To Sand Between Layers Of Fiberglass? 

When you install two or more layers of fiberglass sheets on the boat flooring, sanding is not required. They stick to each other quite well if you maintain a few tactics. 

Firstly, you need to wait for the first layer of fiberglass to settle down on the floor. Then before you adhere to the second layer of fiberglass, use coarse paper to gently scrub off the fibers sticking out.

Then stick the second layer of fiberglass on the boat flooring. In this way, you can keep installing the layers of fiberglass without sanding between the layers. 

Can You Fiberglass A Fiberglass Boat Floor? 

If the original boat flooring is made of fiberglass, you can still choose to have additional protection by fiberglassing it. The process is the same as fiberglassing any other flooring. 

But the confusion appears while adhering fiberglass to fiberglass. There are a few components that are the best for attaching layers of fiber glasses:

  • Cyanoacrylate adhesive
  • Two-component epoxy
  • Structural acrylic
  • Polyurethane adhesive

These are the common adhesives that would effortlessly adhere to a fiberglass sheet on a fiberglass boat floor. 

Can I Fiberglass Over Plywood?

Yes, fiberglass can be applied over plywood to create a strong, durable, and waterproof surface. Before fiberglassing, ensure the plywood is clean, dry, and properly prepared. Use marine-grade plywood for enhanced moisture resistance. 

Begin by applying a coat of resin as a sealer to the plywood surface, allowing it to cure before proceeding. Then, lay the fiberglass cloth or mat over the plywood, ensuring it is smooth and free of air bubbles. 

Apply multiple layers of resin, allowing each layer to cure fully. Sand the surface between layers for better adhesion. Properly executed, fiberglassing over plywood can provide a reliable and long-lasting protective layer.

What kind of fiberglass for boat floor?

For boat floors, fiberglass is commonly used due to its strength, durability, and resistance to water. The most suitable type of fiberglass for boat floors is typically woven fiberglass fabric, often referred to as fiberglass cloth or mat. 

This material is layered with epoxy resin to create a sturdy and waterproof composite structure. Woven fiberglass fabric is available in various weights and weaves, allowing you to choose the one that suits your specific boat flooring needs. 

A heavier fabric offers greater strength, while lighter ones can be used for less demanding applications. It’s crucial to follow proper installation techniques and use marine-grade epoxy resin to ensure a long-lasting and watertight boat floor.

What is The Best Fiberglass Resin for Boat Floors?

When choosing a fiberglass resin for boat floors, it’s essential to consider marine-grade resins designed to withstand the challenges of a marine environment. Epoxy resin is often the preferred choice for boat construction and repair due to its excellent adhesion, strength, and resistance to water and UV exposure. 

West System Epoxy and MAS Epoxies are popular brands known for their quality in marine applications. These resins provide durability and long-term protection for boat floors. 

However, it’s crucial to follow the manufacturer’s instructions and take safety precautions when working with epoxy resin, as it involves mixing and potentially harmful chemicals.


You have not only learned about the method of fiberglassing a boat floor in this article, I have also included some information that will clear out your confusion regarding fiberglass boat flooring. 

Now that I have provided all the necessary information about fiberglass boat flooring, it is your turn to decide! 

Jahidul Alam

Hello dear! This is Jahidul Alam. I am the admin of this Tidy Floor. I have been in the floor cleaning business for the last 20 years. My business is all about ensuring affordable flooring cleaning services for Americans.

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