Water Damaged Particle Board Subfloor – Removing & Replacing

Is your Particle board subfloor Ruined due to water damage or excess moisture? Not sure If it can be repaired or it should be replaced?

In this guide you will learn:

  • Common Issues with Moisture damaged Particle board subfloors,
  • How to tell If you Can Repair the particle board or it should be replaced,
  • How to Repair or Replace your Damaged Particle board subfloor or subfloor underlayment.

Particle board and water don’t mix! When compared to other types of subfloors such as plywood or OSB , particle board is the worst when it comes to moisture resistance.

Due to particle board being easily water damaged it’s not the best material to use in subfloors or as an underlayment in subfloors.

If used in subfloors, wet particle board can not only cause your floors to become unstable but also start losing their structural strength and start to rot!

When not properly installed and exposed to excess moisture or a water leak your Particle board subfloor will suck up all the moisture just like a sponge.

Once this happens the particle board will start to swell up, start bulging and start to fall apart with time.

Signs of Water Damaged Particle board Subfloor:

  • If you have a carpet, you will start to see small visible humps that can also be felt when walking over it.
  • If you have Laminate or Solid wood Flooring, the floors can start to bulge up and create ”bumps” in them.
  • For laminate, the joints can start to come up as the subfloor under it expands and bulges.
  • If a lot of moisture has saturated your particle board subfloor you might even see discolouration on your flooring.
  • Noticeable smell of Mold or Mildew, this will be the most apparent if the water damage has gone unnoticed for a longer period and mold has started to grow in the damp Particle board.

Most of the times after a large water damage such as a flood or pipe leak it will make more sense just to replace the entire subfloor than try to repair and salvage the old one.

Often times you are going to notice the particle board water damage at a very late stage where it already has started to completely fall apart and even has started to rot!

The only option, in this case, is to Replace the water damaged particle board subfloor or parts of it. Usually, it’s best to replace it with plywood to avoid future problems and increase structural strength.

If your Particle board subflooring has recently got water damaged after a large leak or flood, it’s extremely important to properly dry it out as soon as possible and replace the worst areas with new particle board.

This is to avoid any possible mold growth ,or even worse,wood rot to take over the structure of your house!

It’s important to know that Even if you manage to completely dry your water damaged particle board, most of the swelling and bulging won’t come down and it won’t return to its original shape.

Please note, Using only Particle board as the only layer in the subfloor in residential homes is extremely dangerous, as it has very little structural strength when walked over.

Particle board in 99% of the cases will be used over a Plywood or other type of subfloor as an underlayment if it’s resting on joists. If you are not seeing this in your house, you got a serious problem, especially if your Particle board subfloor has been water damaged!

Water Damaged Subfloor?

Call 844-488-0570 for a Risk Free estimate from a Licensed Water Damage Restoration Specialist in your area.

We Can Help Find the Cause of this,Dry out your Subfloor & Repair/Replace the water Damaged Particle board.

How to Repair Water Damaged & Rotten Particle board Subfloors

1.Locate the Floor Joists & Mark them out

Usually to remove the water damaged Particle board subfloor you will need to cut it out, before we remove the particle board it’s important to mark the locations of the joists so as not to cut into them accidentally.

For this, it’s best to use a stud finder.

2.Cut out/Remove the Water Damaged Particle board

This can be best done with a circular saw that is set to a proper depth. Before cutting it’s important to be aware of any wiring or pipes that may be hidden behind the subfloor in case you accidentally cut it too deep.

Remember if the subfloor is resting over the joists, 99% of the time there will be an additional layer of Plywood subfloor which might give you an extra safety margin.

Still, you do not want to cut in your plywood sub-subfloor too much either way as it can affect its structural strength.

Using a prybar remove the water damaged particle board pieces, if the particle board is really water damaged and it’s rotten it will be fairly easy to remove as it might even crumble up!

Make sure to remove all of the Damaged particle board subfloor. If you are removing only a part of your particle board subfloor,make sure it’s removed in the right size/shape so you will be able to easily attach the new particle board.

If there is a very light water damage on only some of the Particle board and it’s used as an underlayment over a Plywood/OSB subfloor in some cases it’s possible to physically scrape off the swollen bumps.

This should be done only if the damage is very small and the structural integrity of the Particle board hasn’t been affected. The easiest way to remove the swollen humps is with a chisel and hammer.

3.Deploy Fans/Dehumidifier to dry out the area

Before installing a new particle board subfloor it’s important to remove any moisture that might have been trapped under the water damaged particle board subfloor.

Increasing the temperature in your house, opening windows for better ventilation and deploying fans for more airflow will speed up the moisture evaporation.

Also, you can consider using a dehumidifier for this as well to draw out any remaining moisture.

This step is extremely important and should not be skipped, if you fail to remove all of the moisture this can lead to deterioration of your newly installed subfloor.

4.Install New Particle board Subfloor

Cut the new particle board to the right size,make sure you are purchasing particle board that is of the same thickness as the old one if you are only partially replacing it.

You can install the new particle board subfloor with either nails or screws, a grab-adhesive also can be used for sealing / extra adhesion.

If you are considering replacing your whole subfloor, I would really suggest to install a Plywood subfloor.

This is especially true if you are repairing a water damage in bathroom.

It might be a bit costlier than particle board,however it won’t get water damaged as easily as Particle board in future. Not only that, it will also provide better structural stability.

If you are hiring someone to do this for you, the total cost won’t be that much different!

When to Call a Professional

In case of a small leak and if there’s only a small bulging in one or two places of your Particle board subfloor it’s perfectly possible to repair it yourself as a DIY project.

If the water damage is substantial and you suspect that your particle board subfloor has lost its structural integrity or has started to rot it would be advisable to get an expert to do this.

If there is a recent large water damage,such as a flood situation and the water has got in your subfloor, it’s important to properly dry it out as soon as possible and repair/replace any water damage to avoid much larger problems.

Water Damage Restoration Professionals have industrial-grade equipment that can be effectively used to remove and dry out the water before it has a chance to do substantial damage to your home.

We have Water Damage Restoration Technicians that can help Dry out your Particle board Subfloor & Repair/Replace any Water Damage to your Floors and Subfloor.

For Disasters of all Sizes,available in 95% of the USA


Scroll to Top