Why Do Mobile Home Floors Get Soft And Spongy? (Eight Reasons)

Living in a mobile home is considered trendy and cost-effective.

However, maintaining such homes to always be in good condition is challenging, unlike if you live in a permanent home.

Soft and spongy spots in a mobile home are common, and you need to fix such problems once you notice them.

So, Why Do Mobile Home Floors Get Soft And Spongy?

The main cause of a spongy or soft floor in a mobile home is water. There is probably a leakage at the subfloor of that soft spot, or you expose the floor to regular water contact. For instance, if you place a pet’s water drinking bowl in one place of the mobile home, the floor will start getting affected. To be safe, reduce the extent to which you allow water to get in contact with your floor.

In this article, you will get more information on replacing spongy floors, what causes the spongy and softness of a floor in a mobile home, and how to avoid it.

Additional Mobile Home Floor Topics
What Causes Mobile Home Floors to Buckle?
Why Do Mobile Home Floors Get Soft And Spongy?
Why Is Your Bedroom Floor Wet When It Rains?
Why Is Your Mobile Home Floor Cold in One Spot?
Why Is Your Mobile Home Floor So Cold?
Why Is Your Mobile Home Floor Uneven?
Why Does a Mobile Home Floor Make Noise?

Eight Common Causes Of Soft, Spongy Floors

There are several reasons why your mobile home gets spongy, but almost all of them are water-related.

The moment you learn how to manage water flow and usage in your home, you will rarely experience the challenge of soft floors.

Some of the common causes of spongy and soft floors include

1. Plumbing Leakage

You may be having a leakage on the plumbing system.

The underfloor leakage will make your dry floor get soft and spongy.

If not attended to, the damage can extend to a very large part of the floor or, worse, the entire house.

2. Continuous Exposure To Moisture

When the floor gets exposed to water continuously, chances of sagging or getting soft ate very high.

For instance, if you like washing the floor with a lot of water, it will gradually get soft and spongy.

3. You Are Putting Pet Water At The Same Spot

When you set a specific water point for your pet, the area gets wet several times a day, and you may not be in a position to monitor your pet every time it spills water on the floor.

That water drinking spot will start to get spongy.

4. Moisture From Humidity

Moisture from humid air can condense to water and damage the floor.

5. Poor Insulation

Poor home insulation is a cause for spongy and soft floors because it does not absorb all excess heat in a house.

The unabsorbed hot air can condense and damage the floor.

6. Roof Leakages

Your floor is getting soft, maybe because the roof has leakages that allow rainwater to flow inside the house.

7. Faulty Door And Window Sealant

Problematic door and window sealants can be an entry point of outside water and moisture to your floor, thus making it spongy.

8. The Home Is Over 10 Years Old

Nothing lasts forever; mobile homes too can get damaged after many years of use.

It is advisable to always replace the floor after a few years of use.

Five Step Problem Floor Correction Process

Having spongy and soft floors is the last thing a mobile homeowner can wish for.

If your home is already damaged, here are a few steps you can follow and repair your damaged mobile home floor.

You can choose to DIY if you have mastery of the technical aspects of home repair or just hire a qualified person or company to do it for you.

1. Determine The Area To Be Repaired

Before repair, you need to identify where and to what extent you are supposed to repair the floor.

When you step on the floor and feel it is soft or spongy, you will need to take a few gentle baby steps around the area or use your hand to gently press the floor and determine the extent of sponginess.

Replacing the entire floor is unnecessary because it is more costly than replacing a small damaged part.

However, if the sponginess is scattered on the entire floor, you should consider doing a full floor repair.

But if the sponginess is on a small area, there is no need to replace the entire floor. You can only work on the small damaged part.

2. Remove The Damaged Part

This is one of the critical part of the process.

You are careful not to destroy the joists holding the sub-flow space because destroying them can lead to a great mess up your work.

Use a jigsaw to cut out holes in the floor to easily remove the damaged space.

After cutting, gently remove any soapy part of the floor without considering the remaining open shape.

It is not always necessary that the subfloor space have a regular-shaped joist.

After clearing out all the dirt and saggy, soft floor parts, dump them in a dumpsite or pit. You can then start preparing joists to fit in the now open subspace.

3. Replace The Sub-flow Space With New Material

Once you fix new joists, you will need to fill the open flooring spaces with new material.

Many mobile home subfloors are made of compressed board, but plywood is also a good option, especially during replacement.

When choosing the new subfloor material, make sure it is the same width as the original subfloor.

This way, the levelling process will be quite easier.

When cutting the new plywood, accuracy of measurements is essential.

Take correct measurements of the open space and transfer them to the plywood for cutting.

The cut material should fit in the spaces as tightly as possible.

4. Level The New Subfloor

Use a level sensor to determine if the subfloor is flat.

You can also use your legs by slightly stepping on the filled subfloor.

If it is not flat, you will feel some bumps and valleys on the floor as you move.

If the subfloor open space were bumpy, the subfloor would also be bumpy.

If you wish to skip this levelling step, you can use the self-levelling cement-based underlayment.

5. Replace Flooring

Once you are done with the sub-floor and have ensured that it is well levelled, the winding-up step is to place a new flooring on the replaced subfloor.

You can use wood, tiles or even carpet. For many mobile homeowners, a carpet is also preferable because it is relatively cheap and easy to place on the subfloor.

After this step, you should have a beautiful, flat, and hardy floor for several years to come.

Once you achieve this, you will have completed the repair and keep enjoying stepping and working on a firm floor.


Sturdy floor space is essential whether it is a new or old manufactured home.

To ensure your floor is always firm, you need to avoid exposing it to the vulnerability that causes water to its floors.

In case you have already experienced the problem of a spongy floor, this article is meant for you.