Is your mobile home subflooring damaged and in dire need of replacement? If you answered yes, you are in the right place. This article will cover everything you need to know about replacing mobile home subflooring and provide an in-depth guide on how to replace mobile home subflooring yourself.

So, let’s get into it. 

What is a Subfloor in a Mobile Home?

Generally, the subflooring of your home is the bottom-most layer of flooring that rests on the joist and supports all the other layers. The subflooring is a structural part of the floor. Traditionally, mobile homes and manufactured homes have subflooring made of particleboard, a combination of sawdust and glue. Particleboard is highly vulnerable to moisture and dampness, leading to soft spots, rot, warping, and bowing.

However, particleboard is not used anymore in newer mobile homes as it tends to break down in high traffic areas. Instead, OSB or higher-grade plywood is used as subflooring in newer mobile homes, which can withstand moisture and dampness a lot better compared to particle boards. But small leaks and regular encounters with water can still damage the subflooring and lead to soft spots or bowing in some areas. 

How to Check If Your Mobile Home Subflooring is Damaged

One of the most common signs that indicate your mobile home subflooring is damaged is it will feel spongy and uneven. In a more severe case, you might see holes in the floor. If a part of your floor feels spongy, take small steps around the area and identify the soft spots or unlevel areas. 

You will need to replace the entire area after marking the damaged subflooring. Many people tend to repair the soft spots only and skip the adjacent areas. We do not recommend it as it can damage the newly installed subflooring and cost you more in the long run. However, in most cases, replacing your home’s entire flooring is not necessary. For example, if you have damage in high moisture areas such as the laundry room, bathroom, or a leak in the pipes, you can get away with replacing those areas only. Replacing more flooring than you need to is both unnecessary and costly. 

How Much Does It Cost to Replace Mobile Home Subflooring? 

The main costs associated with replacing mobile home subflooring are –

• Subflooring material
• Extra materials
• Labor cost

These costs vary depending on your location, the size of the area, and additional circumstances such as your joists’ condition, leaks, and other damages. If you are replacing the mobile home subflooring yourself, the subflooring material will account for the majority of your cost. 

Here is a list of per square footage price of common subflooring materials to give you an estimate before you start your project –

Subflooring Material	Price Per Square Foot
Plywood	$1.50
DRIcore	$1.65
Amdry	$3
Tyroc	$2.70
Barricade	$2.25
Warmboard	$7

Tools and Materials You Need to Replace Mobile Home Subflooring

Before starting this project, consider whether you should replace the mobile home subflooring yourself or bring in a professional. Our recommendation is if you have some construction experience and have done a few DIY projects here and there, you might be able to replace the subflooring yourself. But for someone who has never even hit a nail with a hammer, leaving it to the professional would be the best option. 

We would rate replacing mobile home subflooring a solid seven on a difficulty scale of 1 to 10, meaning it is doable with caution and some experience.

Here is a list of tools and materials you are going to need to replace your mobile home subflooring –

Tools

• Circular Saw
• Hammer
• Pry Bar
• Knife or Blade
• Scraper

Materials

• Subflooring material
• 2×6 lumber
• Galvanized Screws
• Liquid Nail Adhesive

Step-by-step Process to Replace Mobile Home Subflooring

Step 1: Remove trim and floor covering

The first step of replacing your subflooring is removing the first layer of flooring, the trim, and floor covering or finished flooring. The details of this step depend mainly on the type of flooring you have. Follow this detailed guide to remove your floor covering. 

After removing the floor covering, assess the floor for leaks. The source of the damage is usually a faulty pipe or window or roofing issue. Either way, you have to repair the leaks before moving on to the next step.

Pro tip: Manufactured homes are built in layers, and the walls are installed after the subfloor. Meaning removing and replacing the subflooring under the walls require special tools. Therefore, we recommend investigating the subfloor under the wall for damage. If it is in good shape, leave it alone to avoid unnecessary trouble. 

Step 2: Cut the subfloor out

Removing the existing subflooring is the most tedious part of this project. Be very careful to make sure you are not damaging the joists underneath, which is a structural component of the house. 

Before cutting the subfloor, you will have to measure its thickness. Typically, subfloors are either 3/4″ or 5/8″ in thickness. After measuring the subfloor thickness, set your circular saw to your measured subflooring height. Then proceed to cut the subfloor by following the perimeter along the edge of the room. The circular saw will cut the subfloor as close as 6 inches from the wall. If you need to remove subflooring closer to the wall, you will need a Dremel. 

After cutting the subflooring around the edges, the next step is to cut them into smaller pieces to make it easier for you to remove them. The smaller you make each piece, the easier it will be to remove the subfloor. If there are no pipes and wires between the joists, you can simply run the saw between each piece and remove them. 

If the subflooring under the wall is rotted or damaged, you can cut out an inch or so under the wall without causing any damage. It should give you enough space to slide in the new subflooring. 

Step 3: Inspect the joists

Now that you have got the subflooring out of your way and have a full view of the joist, you might want to make use of this opportunity and inspect your joists for any damage. If you notice any damage, you can either reinforce it using a 2×6 or remove and replace the particular section. 

We recommend reinforcing minor damages as replacing the joists can be tedious. To reinforce the joists, measure the spacing between the joists and cut the lumber to the right length to fit between the joists.

Step 4: Add insulation

Poor insulation is the most significant source of heat loss in homes, which accounts for about 35-40% of heat loss. So, insulate your flooring properly to save up on your electric bill in the future. Run the insulation under the wires and pipes so the heat from home can get to it.   

Step 5: Lay the new subflooring

This step is divided into two sections, laying the new subflooring along the perimeter and the rest of the room. Around the perimeter of the room, you will need to attach an additional 2×4 to the original so that you have a shelf or lip to lay the new subfloor. Additionally, where one piece of plywood ends and another begins, you will need to reinforce it at each seam.

You will have to add a 2×4 between the original joists, so you have a base to nail and glue down the plywood. Lay the subflooring in the same direction as the original, which usually runs perpendicular to the joists. 

Step 6: Install new floor covering

The most rewarding part of this entire project is the next step — choosing and installing a new floor. Lucky for you that mobile home flooring options have expanded vastly in the past few years. Here is a list of the best options for mobile home flooring to help you pick the right flooring for your manufactured home.

And voila! Enjoy your new mobile home flooring. 

Do you have any questions about how to replace mobile home subflooring? Comment below and let us know!