The Ultimate Guide To Replacing Your Boat's Deck Floor

Boat floors are exposed to harsh natural elements, such as UV rays and saltwater, which can cause wear and tear over time. Replacing a boat deck floor is a significant decision and a complex process, often requiring hundreds of hours of labour. Before starting, it is essential to check for rot in the transom, build a cradle to support the boat's hull, and remove all items from the boat. The old floor can then be dismantled, and any rotten components replaced. The new floor can be measured, cut, and laid, before being covered with a fibreglass mat and resin. Finally, the boat's components can be reinstalled, leaving you with a sturdier boat and a new lease of life on the water.

Check for signs of rot

Checking for rot is an important step in boat maintenance and repair. Here are some detailed instructions to help you identify and address any rot issues in your boat's deck:

Inspect for Signs of Decay:

Start by thoroughly examining the exterior and interior of your boat, including the flooring, transom, fixtures, deck, and other surfaces. Look for any signs of discoloration, sagging, or giving way under pressure, as these could indicate the presence of rot. Pay close attention to areas where fresh water is likely to accumulate, such as the deck seams, transom, hatches, and exposed end grain.

Test for Hollow Spots:

Use a hard object, such as a hammer, to tap on surfaces that are susceptible to water damage. Listen for a hollow or "dead spot" sound, which could indicate rot below the surface. This method can help you identify potential problem areas that warrant further investigation.

Probe Suspect Areas:

Once you've identified potential rot spots, use a sharp tool like a knife, scraper, or ice pick to lightly pick at the surface. This will help you determine if the wood is rotten at its core. If you find rot, allow the area to dry completely before proceeding with repairs.

Sense the Funky Smell:

Rotten wood can emit a distinct odour, often described as resembling funky sunbathed mushrooms, sweaty sports gear, or mothballs. Trust your nose to help identify potential rot. If you detect this unpleasant smell, it's a good indicator that there may be rot present, even if it's not immediately visible.

Drill Test for Confirmation:

One of the most reliable ways to confirm the presence of rot is to perform a drill test. After locating soft spots by tapping with a hard object, use a hand drill to drill a small hole through the fiberglass. If the drill pushes the wood down easily, it confirms the presence of rot.

Address the Rot:

If you identify rot, it's important to take action to maintain the integrity of your boat's structure. This may involve seeking professional help from a boat repair shop. Products like "Git"-Rot, a two-part liquid epoxy, can be injected directly into the wood to treat rot at its source without requiring extensive disassembly.

Remember, rot in boats typically starts from the bottom up, so be sure to regularly inspect your boat's hull and transom for signs of decay. By staying vigilant and addressing rot promptly, you can help ensure the safety and longevity of your boat.

Remove everything from the boat

Removing everything from the boat is an essential step in the process of replacing your boat deck floor. Here are some detailed instructions to guide you through this step:

Firstly, it is important to disconnect any wiring or connections before removing items from the boat. Start by removing all the seats, consoles, and fixed items attached to the previous deck. This includes items such as the motor, consoles, and seats, which may have wiring that needs to be carefully dealt with. If your boat has an outboard or I/O motor, you will need to learn how to remove it properly.

Next, you will need to deal with the old flooring. It is advisable to keep as much of the old flooring intact as possible. This will serve as a useful template for measuring and cutting your new flooring pieces. It can also guide you in lining up screw holes during the reassembly process. Leaving a three-inch trim of the old flooring around the edge of the boat is recommended to prevent puncturing the side of the boat and to provide support for the new floor.

Once you have taken out everything from the boat, you can start inspecting and diagnosing the condition of the underlying structures, such as the stringers and foam. Check for signs of rot or decay, as this will determine the extent of the replacement needed. Remember, boats typically rot from the bottom up, so pay close attention to the areas closest to the hull.

After assessing the damage, you can start removing the rotten or damaged components. Use appropriate tools, such as a circular saw or a mini tiller, to carefully cut out and scrape away the affected areas. Make sure to maintain the former floor's dimensions when removing the old flooring to ensure a proper fit for the new floor.

Finally, before moving on to the next steps of the replacement process, it is essential to clean and prepare the area. This includes removing any remaining debris or dirt and ensuring that the exposed areas are ready for the installation of the new flooring.

Remember, safety should always come first. Wear protective gear, such as a respirator or mask, to safeguard yourself from dust and fibres during the removal process.

Dismantle the old floor

To dismantle the old floor of your boat, start by removing everything attached to the deck, including the consoles, seats, and wirings. You will also need to get the motor out.

Next, determine the ideal depth for your circular saw before cutting the floor to avoid damaging the hull. A common depth figure for this step is ⅝". It is also a good practice to leave at least 3 inches of the previous floor up to the boat's edge. Doing this ensures that you don't damage the boat's side and can also provide support for the new floor.

Once you've removed the old floor, check for other rotted parts, such as the stringers and the foam. If the foam is still intact, you may only need to replace the wood. Otherwise, you will need to take it out. A mini tiller is a useful tool for removing damaged foam.

Now, you can start measuring and cutting the plywood for your new floor.

Measure and cut plywood

To measure and cut plywood for a boat floor replacement, you'll first need to remove all the damaged or decayed parts of the boat floor. This includes any rotten components, like the stringers and foam, which often rot along with the floor. Once everything is removed, you can start measuring and cutting.

Begin by laying down the plywood you've purchased, using portions of the original floor as a guide for how much to cut. Double-check your measurements with a tape measure before cutting. You can also use the old flooring pieces as templates to mark screw holes that will be useful when reassembling your deck.

After cutting the plywood to size, apply a coat of epoxy to the areas of the new plywood that will be joined to provide water protection. Once the epoxy is dry, use a drill to mark out the appropriate areas of the plywood that need to be screwed in place. It's better to have holes as a guide when laying down the cut plywood.

Finally, cover the plywood with a fiberglass mat and seal it in place using fiberglass resin. Once the resin is dry, you can choose to sand the edges for a smoother finish.

Cover the floor with fibreglass mat

Once you've laid down the plywood, the next step is to cover the floor with a fibreglass mat.

First, apply epoxy to the areas of the plywood that will be included to provide water protection. Once it has dried, use a drill to mark out the areas of the plywood that you need to screw in place. It's better to have holes as a guide when laying down the cut plywood.

Assuming you're not adding a layer of foam, lay down the fibreglass mat on the plywood. Use the resin to seal it in place. Once it has dried, you can choose to sand the edges to smoothen them. You can then screw the mat in place.

Fibreglass is a great option for boat flooring as it is a naturally high-traction and grippy material, which helps to keep feet safely and securely on the surface of the deck. It retains this level of traction even when water pools and covers the boat deck surface, greatly reducing the chance of someone losing their footing and suffering an accident. Fibreglass is also soft and pliable enough to relieve the feet and ankles of stress and built-up pressure that can accumulate over prolonged periods of standing.

Frequently asked questions