How To Fix Water Damaged Fiberboard: Easy 5-Step DIY Guide

Fiberboard is a versatile material that you may find in a variety of applications around the house. Our question is, how to fix water damaged fiberboard when things go south? In this process, you can also check out how long before baseboard gets damaged from water since they have similar properties with fiberboards.

It’s a material you’re probably familiar with, from kitchen cabinets to durable, lightweight furniture. Accidents happen, and water damage to the board is not uncommon. The surface will inflate and lose its smooth form as a result of this.

how to fix water damaged fiberboard

Fortunately, repairing a water-damaged fiberboard isn’t that difficult. If the water damage is minor, it may be possible to fix it at home. To repair water-damaged boards in your home, follow our step-by-step instructions below.


Repairing Water-Damaged Fiberboard

Fiberboards and particle boards are practically the same thing, so you won’t have a hard time fixing your water damaged materials. If you need an extra guide, check out this article on how to repair particle boards.


Step #1. Dry the wet areas

Drying the wet piece of water-damaged fiberboard is the first step in mending it. Allow plenty of time for this stage because it takes a long time to dry naturally.

Tip: You can use anything like a hairdryer to speed up the process if you’re in a rush. Point the hairdryer to the damp area. Hold it for a minute to allow the particle board to dry evenly.


Step #2. Buff off with sandpaper

The surface of the fiberboard may be uneven once it has dried. After that, you’ll use sandpaper to smooth out the elevated area. Buffing the damaged area will help your surface-level out.

The dry section of the fiberboard will be exposed when you buff it. You’ll wish to get rid of the material’s damaged areas.

Tip: When removing damaged areas of the fiberboard, use medium-grit sandpaper. When polishing the repair, you should utilize finer grit sandpaper.

The sheets are smoothed out by buffing the spots. You have the option of finishing with a waterproof coating to avoid dealing with the rising wet problem in the future.

If you’re going to use a waterproof coating, make sure it’s completely dried before moving on to the following step. Use this time to clean up any leftover messes from the first two processes of particle board repair.


Step #3. Remove the damaged areas 

You’ll remove the damaged areas of the particle board once your waterproofed particle board has cured or your material has been sanded down. Cut out the bloated and affected sections of the board using a knife.

Remove any parts that have developed a powdery texture or have become moist. Again, you’ll want to allow your board time to dry at this point.

Vacuum out any powdery pieces of particle board with a suction tool. Whatever is left can cause the particle material to deteriorate from the inside out.


Step #4. Add the wood filler to the holes

You should purchase a can of wood filler. Follow the instructions on the label to put it all together. Apply the wood filler to the spots you’ve made using a knife or a scraper.

Make sure it’s level with the rest of the board by using the tool. Scrape away any extra filler to ensure an equal surface throughout the entire particleboard.


Step #5. Sand to finish

After your wood filler has dried, sand it smooth with a fine-grit sandpaper. This final sanding ensures that the entire finished board is smooth and even.

Now is an excellent time to apply another coat of waterproof sealant. It will ensure that your board does not sustain the same harm in the future.


How do you repair fiberboard cabinets that have been damaged by water?

To repair water-damaged portions of fiberboard furniture, use a sharp razor to remove the damaged regions and fill the space with wood filler and smooth sand.


What is the best way to seal pressed wood?

As a first coat, use a low-cost white or gray primer. Because pressed wood is porous, it quickly absorbs paint.

Because the wood will absorb the first layer of primer, you must apply multiple coats to seal the wood. After using the primer, make sure you have a solid color.


Is it possible to screw into wood filler?

No. The structural capability of wood filler is zero — it’s only for show. If you need to repair a stripped screw hole, get some little pieces of wood and some white PVA glue, then pour a load of cement into the hole and jam the pieces of wood in.


What’s the best way to plug a screw hole that’s too big?

Fill the hole with any wood-safe liquid glue (Elmer’s, for example). Using numerous wood toothpicks, cram them into the hole until they’re very snug and fill it.

Allow it to dry entirely before snapping the toothpick ends flush with the surface. Insert your screw into the hole that has been fixed.



If the water damage is severe, it may be more cost-effective to replace the damaged parts with a new particle board completely. If it becomes too convenient, call in the experts! Hopefully, we’ve provided you with enough information on how to repair water damaged fiberboard.

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