Why Your Caravan Floor Is Spongy (Plus 3 Easy Fixes)

Suppose you’re walking around your caravan and suddenly realize that some parts of the floor feel spongy. In that case, you might become perturbed as you wonder why your caravan floor has suddenly turned this unsettling consistency. If you notice your caravan floor is spongy, don’t panic, as it’s a common problem experienced by many caravan owners.

Your caravan floor can be spongy due to delamination; the adhesive holding the layers of the caravan’s floor is worn off due to wear and tear. It could also be spongy due to water damage to the floor. Easy fixes include repairing or replacing the damaged sections or hiring a professional.

In this article, I’m going to explain why your caravan floor is spongy and the three best ways you can fix it. Let’s get started!

Why Your Caravan Floor Is Spongy

As mentioned above, your caravan floor could be spongy due to various reasons. Below are some of the most common:

Delamination of the Caravan’s Sub-Floor

A caravan’s sub-floor is the floor under the carpet or vinyl. The sub-floor typically has three layers sandwiched and laminated together through a special sealant. The bottom layer is thin plywood, the middle layer is high-density insulation material, and the top layer is thick plywood.

Over time, delamination starts to occur as the sealant becomes weak and less effective, and the layers of the caravan floor start to separate. When delamination begins, some parts of your caravan begin to feel spongy. Delamination usually starts in areas of the caravan floor that people walk on often.

Delamination is likely to affect the following areas first before spreading to other spaces:

Around the kitchen sink
In the living area
The door entrance
Areas below heavy furniture or equipment

Internal Water Damage to the Caravan’s Sub-Floor

Another reason why your caravan floor is spongy could be internal water damage to the caravan’s subfloor. When water from the motorhome seeps into the caravan’s floor, it may get trapped inside, damaging the sub-floor. When this happens, your caravan floor starts to feel spongy.

Damage to the Caravan’s Sub-Floor by Water Ingress

Water ingress could also be the reason why your caravan floor is spongy. Water ingress occurs when water from outside enters your motorhome, gradually penetrating your caravan’s sub-floor. Water ingress can cause untold damage to your motorhome, including making the caravan floor spongy.

Common Factors That Affect Your Caravan Floor

Delamination, internal water damage, and water ingress all result from a few common root causes. Below are the some of the most common factors that may negatively affect your caravan floor:

Escape of Water

Escape of water in a caravan refers to a water leakage. Escape of water is one of the leading causes of internal water damage to the caravan floor. If there’s a leakage in the caravan, the water seeps to the bottom, and with enough time, you’ll start noticing some sections of your caravan floor becoming spongy.

Some of the main causes behind water escape are:

Poor insulation: Interior humidity can occur when your caravan is not well insulated. The excess water in the motorhome can, over time, escape into the caravan floor, causing sponginess.
Water leakage: Water can leak inside the caravan due to a plumbing issue such as a leaking tap, burst pipe, or leaky valves. When the water leaks into the floor unchecked, it can eventually make the caravan floor spongy.
Faulty appliances: Sometimes, faulty appliances in the caravan can also cause water escape. For instance, a leaking fridge can cause water escape, eventually leading to a spongy caravan floor.

Where You’ve Parked the Caravan

Sometimes, you have to park or store your caravan in one spot for days. If you park your caravan inappropriately, water ingress could occur. As mentioned earlier, water ingress happens when water from outside enters your caravan; it can cause a wide array of issues, including making the caravan’s floor spongy.

Some of the causes of water ingress are:

Leaving Your Caravan Uncovered

If you leave your caravan uncovered for an extended period, water from rain, ice, or snow can eventually damage it. Additionally, water can enter the caravan causing untold damage such as making the floor spongy. It’s best to park or store your motorhome in a covered area to protect it from water ingress.

Alternatively, you can use a good quality caravan cover such as Maypole Caravan Cover (available on Amazon) to protect your motorhome.

Lack of Proper Maintenance of the Caravan

Another cause of water ingress is the lack of proper maintenance of the caravan. Suppose you don’t maintain your caravan regularly. In that case, you’ll not notice minor issues such as faulty windows and doors or holes in the caravan’s body.

If minor faults go unchecked, they could lead to water ingress that could cause eventual damage to the caravan’s floor. It’s, therefore, essential to maintain your caravan regularly to prevent water ingress that could make the floor spongy.

The Age of the Caravan

In many older caravans, the floors are composed of a single layer of plywood, and are thus not well-protected. As a result, any water that seeps into the floor, either from water escape or water ingress, can’t escape back. The trapped moisture has led to damage to the caravan floor and, thus, sponginess.

Moreover, the roofs of some of the older caravans were of canvas material. The canvas is not strong enough; therefore, the water can enter through it into the floor of the caravan, and the floor eventually becomes spongy.

As the years go by, the caravan experiences wear and tear, delamination occurs, and the floor becomes spongy.

3 Easy Fixes for a Spongy Caravan Floor

Caravan manufacturers design them in a way that enables the motorhomes to withstand even the harshest weather elements. However, delamination occurs as the years go by, and the caravan floor becomes spongy.

If you find that your caravan floor has become spongy, it’s best to do the following before fixing it:

Identify the cause of the spongy caravan floor; is it due to delamination, water escape, or water ingress?
Assess the magnitude of the damage to the floor.
Decide on the best way to fix the spongy floor.
Attend to the root cause immediately to stop further damage to the floor.

Below are 3 easy fixes for a spongy caravan floor:

1. Repair the Spongy Caravan Floor Using a Suitable Adhesive and Wooden Dowels

Suppose, after assessing the extent of damage to the floor, you discover some parts of the subfloor are spongy due to delamination. You can repair the spongy sections using an appropriate adhesive such as the Pennine Caravan Soft Floor One Shot Delamination Repair Kit (available on Amazon) and wooden dowel plugs.

Below are some benefits of using a suitable repair adhesive to repair your spongy caravan floor:

The adhesive helps to bond the damaged floor of your caravan.
It creates a strong support structure for your caravan floor.
It’s an excellent solution for a spongy caravan floor as the floor can remain intact for years to come.

The benefits of using wooden dowels to repair your spongy caravan floor include:

Wooden dowel plugs help you to make solid and accurate joints when repairing your spongy caravan floor.
They are easier to use in DIY projects than nails and screws.
Dowels are sturdy and thick and thus give your repaired caravan floor additional support.

Repairing a spongy caravan floor requires suitable materials, tools, patience, and precision. Here’s how to fix the section of the spongy caravan floor using a repair adhesive and wooden dowel plugs:

Gather the equipment and supplies you’ll require for the job. These include a suitable repair adhesive such as Pennine Caravan Soft Floor One Shot Delamination Repair Kit, 8mm wooden dowels such as TREND DWL Dowels (available on Amazon), a sharp chisel, drill, 8mm (0.3 inches) drill bit, a blade knife, hammer, cleaning cloths, broom, disposable gloves, and sandpaper.
Remove the carpet or floor covering to access the spongy section.
Measure and draw 4-inch (10.16 cm) squares over the section you want to repair.
Insert the 8mm drill bit into the drill.
Carefully drill holes at the corners of each square. The holes should go through the top layer of the plywood and the insulation material; the holes should be approximately 5mm (0.2 inches) deep.
Sweep up the debris after drilling all the holes so it doesn’t interfere with your repair job.
Take your chosen repair adhesive and read the instructions carefully.
Put on the gloves.
Go to the point that is furthest from the door, then work towards the door.
Squeeze and inject the adhesive into each hole you drilled.
Fill the hole until the adhesive shows but don’t allow it to overflow.
Insert an 8mm dowel plug carefully into one of the holes.
Press or tap the dowel plug until it is flush with the floor’s surface.
Repeat steps 10 and 11 until you fill all the holes.
Wipe any excess glue in the repaired section using a cleaning cloth.
Allow the adhesive to set as per the instructions on its packaging.
Once the adhesive sets, remove any glue around the dowels using the knife.
Use the sharp chisel to trim the dowels.
Sand the repaired area to remove excess adhesive and protruding dowels for a flush and smooth finish.
Sweep the area you’ve repaired to remove any dust, dirt, and debris.
Refit the carpet or floor covering if still intact or purchase new ones.
Enjoy your brand new caravan floor; if you do a good job, your caravan floor could serve you for years to come.

2. Fix the Spongy Caravan Floor by Replacing the Spongy Section

If, after assessing the caravan floor, you find that the sponginess has occurred due to water damage, you could consider replacing that section of the sub-floor. Replacing a water-damaged caravan floor is possible, especially if you’re a DIY fan. However, it’s essential to have the necessary tools, materials, and equipment.

Here’s how to replace a spongy caravan floor due to water damage:

Rectify the cause of the spongy caravan floor. For instance, fix the internal leaks or water ingress issues that make your caravan floor mushy. Doing so prevents water damage to the floor in the future.
Gather the necessary materials and equipment. These include a circular saw, insulation material similar to the existing one, sub-floor material similar to the existing one, a drill, flooring screws, sealant, a jigsaw, a tape measure, a pencil, and a hammer.
Remove the carpet or vinyl; you can reuse them if they are intact or replace them if they are damaged.
Use the pencil to make a square mark outside the spongy section of the sub-floor.
Find and remove all the screws that connect the subfloor and the floor joists in the marked section.
Cut out the marked/spongy section of the sub-floor using the circular saw.
Pull out the cut section of the sub-floor; you can use the hammer to help you.
Remove the damaged insulation material under the subfloor.
Replace the damaged insulation material with the new one.
Measure the area of the subfloor you have removed.
Use the measurements to cut a new piece of subfloor material; use the jigsaw to cut the new piece of the subfloor.
Install the new piece of subfloor material in the space where you removed the old subfloor.
Use the drill and flooring screws to fasten the new subfloor to the floor joists.
Use a sealing agent such as Unibond Heavy Duty Mounting Adhesive (available on Amazon) to seal the joints between the new and old subfloor. The sealing agent prevents air and water from passing through the joints.
Cover your subfloor using vinyl or a carpet.

3. Hire a Professional To Fix a Spongy Caravan Floor With Significant Water Damage

If, after assessing your spongy floor, you realize that a substantial part of the caravan’s subfloor has suffered from water damage, you could consider hiring a professional to fix the floor. The reason for this is that the magnitude of the damage can affect the caravan’s structural integrity. Additionally, dealing with that kind of damage is no easy feat.

Hiring a professional to fix your extensively spongy caravan floor comes at a cost; it could be more expensive than doing it on your own. However, there are some benefits of hiring a professional. The benefits include:

When you hire a professional, you lift the weight of fixing the caravan floor off your shoulders, thus giving you peace of mind.
Professionals have the latest tools and equipment, so you’re sure to receive excellent work.
A professional does the work quickly and efficiently without compromising the standard and quality of the work.