How to Attach a Roof to a Modular Home

You may have recently acquired your ideal home, but now that it’s in your possession, you may feel that it could use some extra embellishments.

Luckily, you can build an extra room or porch with a roof!

Not only do you get a place for relaxation and entertainment, but you also get shelter when the weather is bad.

How do you do it? Let’s dive in.

How to Attach a Roof to a Modular Home

The entire process can’t be explained in a single sentence but know you can replace your existing roof on your modular home.

When it comes to room or porch additions you will “attach” the roof.

The truth is you can’t technically attach the addition to your home.

You will build the addition extremely close to the home with space between the two. The addition needs its own footers too.

This doesn’t mean you will see gaps or will look funny. The gaps will have seals with plywood and chemicals to prevent any moisture or air from seeping in.

You don’t want to attach it after the home has been set up to avoid shifting issues. Homes and additions will naturally settle over time.

The shift that can occur without proper footers or attaching an extra roof to the home can cause problems.

First, it can cause bearing on the home leading to structural damage, and second, it will violate your HUD Code.

The last thing you want to have is your home settling unevenly or causing damage!

Keep in mind this doesn’t mean you can’t add additions.

You can add them similarly to the way you would with a standard home, but there are a few construction techniques that differ.

The porch roof process features techniques that you’d use to build a deck.

Sunrooms or enclosed rooms will require additional work because of the construction; we’ll get more into that below.

Factors to Consider When Building an Addition with a Roof

The first is to ask yourself if you want a roof is what kind of roof you’d like to install or what is it for (porch, extra room, etc.).

These will determine the cost, time of completion, and overall structure.

You may want a particular style of roof, but it might not be allowed by your city’s code.

In this case, you’ll need to make some decisions if it’s worth breaking code over or if you can just settle for another approved style.

Does the roof style truly matter to you? Does your city have any limitations on additions?

Consider the HUD Code on your home too. The HUD Code tells you what’s acceptable and not for your modular home.

Breaking this code makes your home non-compliant and could bear weight on the home.

It might be wise to seek out contractors that are familiar with HUD Codes or familiarize yourself with your specific home’s code.

The HUD Code includes everything from foundation, roofing, and bolt guidelines.

Find this out before you begin to build. If you can build, you may want to consider the positives of the addition.

For example, you may need an extra storage room or a guest room for visitors.

Porch roofs can provide shade and shelter from the elements for parties or your personal relaxation.

Steps on How to Attach a Roof to a Modular Home

Plan the Size

Once you’ve made your decision, plan the size of the addition. You may want a large area for entertaining or a bedroom.

Alternatively, you may want something small like a roof to cover your front door or patio area to grill when it rains.

If you intend to build a large space, consider how it will look with furniture and the space you’ll need to move around freely.

It might help to draw it out and don’t forget the guests! You don’t want to feel suffocated.


The frame will depend on your addition. If you plan to build an enclosed room, you’ll need a foundation with footers.

The foundation generally consists of a concrete slab at least 12 inches thick. Check with your building codes to ensure you choose the best option.

Porches and decks don’t need a foundation. They can get away with only using footers. Though the studier you build it, the less likely you’ll encounter problems over time.

A foundation can also provide you with extra support should you choose to enclose your deck or porch in the future.


Build and secure flooring before you attempt to add a roof. This coincides with the previous step.

You don’t have to attach the floor to the exterior wall of the home.

However, you do want to build it to the same height as your home.

Building higher will only change the aesthetic and could potentially cause accidents. Think about how many times you’ve tripped over uneven ground.

Railings for Decks/Porches

Railings are considered a huge part of the aesthetic. They come in all kinds of designs and colors.

They do more than just provide you with fancy décor. They provide safety should you need to hold on while walking up or down steps and can prevent you from falling off.

To make railings, you need to have posts to support them.

Place them about eight feet apart and bolt them in place. You’ll want to make any corner posts high enough to support a roof addition.


A roof attachment begins with a ledger board. This board will be placed about 1 ½-inches below the exterior wall of your home.

Generally, you’ll attach the ledger board with lag bolts into studs of the exterior wall of the home. A stud finder will make this process easier to complete.

Next, you’ll frame your roof and attach it to the ledger board. To frame, install a beam on the posts (porches and decks) or the support frame (rooms).

Unless you chose a flat roof, rafters will slant down from the board to the beam.

Realistically, rafters shouldn’t be spaced more than 16-inches apart. This will lead to a weak and unstable roof.

Once the rafters are in place, you can cover the roof with the material you chose.

Commonly, people will use plywood and cover with shingles, but metal roof’s popularity has been on the rise.


Will my home increase in value?

Yes! Despite popular belief that modular homes decrease in value.

They appreciate the same way a standard home does.

If you build a quality addition, you will raise the value. However, you must build it according to HUD Code guidelines.

If you choose to disregard the guidelines and your home becomes noncompliant, you will decrease the value of your home.

Also, you could potentially cause damage to the structure.

How much does it cost?

This will largely depend on the build. Smaller additions will naturally cost less than larger ones.

The cost will change if you decide to build it versus hiring someone else or using a prefabricated kit.

It can typically cost around $2,000 to $10,000 depending on size, materials, and labor.

Do I need a permit to build?

Most likely yes.

Each city has its own set of codes that determine what you can and can’t build. You may live in a city that allows building without a permit.

However, if you live on a lot or land that you don’t own, you may have to contact the owner to determine the rules and regulations.

Should you not consult anyone or not get a permit and build, you could face fines, or your addition may have to get removed.

Final Thoughts

You may have thought that you can’t add on to your modular home because it will lose value. Maybe you thought since it’s a prefabricated home, it can’t expand.

You don’t have to worry about additions to your modular home. Ensure you uphold all HUD Codes and local zoning laws before you begin to build!

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