DIY Roof Addition to a Mobile Home Deck

Adding a roof to your existing deck not only improves the aesthetics but also increases the functionality of your outdoor living space. Whether you're looking for some shade or protection from the elements, building a roof over your deck is a great way to extend your living area. In this blog, we’ll walk you through the steps of building a roof over a back deck attached to a single-wide mobile home. Follow along for a comprehensive DIY guide, complete with tips, materials, and techniques!

Step 1: Initial Planning and Deck Inspection

Before diving into the project, it's essential to ensure your deck can handle the additional load of a roof. Start by inspecting the existing structure to make sure the deck is solid and that there’s enough support for the posts that will hold the roof. For this project, we were able to take advantage of the large, doubled-up two-by-ten rim joists that were already in place, which provided the extra support needed to mount the posts.

If your deck doesn't have this kind of solid structure below the deck boards, you might need to reinforce it with additional deck joist blocking. This will help make sure the posts are securely attached to a stable foundation.

Step 2: Installing the Post Base Brackets

For this project, we chose Simpson 4x6 post base brackets to attach the posts to the deck. These brackets are easy to install and provide a secure foundation for the posts. We attached the brackets to the deck first, which was relatively simple and quick.

Tip: If you don't have strong framing members below the deck boards, consider adding additional blocking for added stability. This could save you time and labor compared to mounting posts in the ground, which would require digging and pouring concrete.

Step 3: Cutting and Installing the Posts

Next, we cut 4x6 posts to the required height for the roof. Though 4x4 posts would have sufficed, we opted for the 4x6 posts to provide more strength and support for the triple-laminated beam that would span the width of the deck.

Using a speed square and a cordless circular saw, we made precise cuts to the posts to ensure they were square and even. The posts were then clamped into place to ensure stability while we continued with the project.

Step 4: Mounting the Beam

The next step involved installing the triple-laminated beam that would span across the posts. The beam was made from two-by-sixes, and we installed them one at a time to ensure that everything lined up perfectly. We attached Simpson strong-tie AC4Z post-to-beam brackets to hold the posts and beam together securely. These brackets are designed to wrap around a 4x4 post and hold the beam in place firmly.

To ensure the beam was stable, we also added a few screws and tightened everything down, checking that the posts were level before moving forward.

Step 5: Attaching the Ledger Board

The ledger board was then attached to the side of the mobile home to create a secure connection between the new roof and the house. We used six-inch lag screws to attach the board to the home's existing roof structure.

Tip: Attaching the roof to the house is optional, but it can add additional security and strength to the roof structure. However, if you're unsure or uncomfortable with this step, you can build a separate freestanding roof structure.

Step 6: Installing the Rafters

Once the ledger board was attached, we installed the rafters. We started by measuring and cutting each rafter to fit properly, ensuring that they were evenly spaced and aligned. Hurricane brackets were used to secure the rafters to the beam and the ledger board, adding extra support and preventing the rafters from shifting over time.

Tip: When cutting the rafters, check for any bowing or crown in the wood to ensure that the rafters are straight and level when installed. This will prevent any sagging in the future.

Step 7: Installing Purlins for Additional Support

After the rafters were installed, we moved on to adding the purlins, which are the boards that run perpendicular to the rafters and provide additional support for the roofing material. We used treated one-by-four lumber for the purlins, attaching them to the rafters using two-and-a-half-inch deck screws.

The purlins should be spaced properly to ensure that the roofing material is supported evenly across the structure. We made sure to place the purlins at regular intervals, which helps prevent sagging and ensures a strong roof frame.

Step 8: Measuring and Cutting the Metal Roofing

Now that the frame was ready, it was time to install the metal roofing. We selected charcoal gray roofing sheets that matched the existing roof of the mobile home. The roofing panels were 3 feet wide, and we had to carefully measure the roof frame to ensure that the panels would fit correctly. We placed the first panel at the edge of the roof and screwed it into place, ensuring it was square.

Tip: The manufacturer recommends installing roofing screws on the flats of the metal panels, not on the ridges. This prevents the panels from moving or bowing over time and ensures that the screws stay tight and secure.

Step 9: Installing the Transition Trim

After the main roofing panels were in place, we moved on to the transition trim that connects the new porch roof to the existing home roof. This piece of trim is crucial for keeping water flowing properly and preventing leaks where the two roofs meet. We slid the trim piece under the existing roof and screwed it into place, ensuring that it fit snugly.

This transition trim helps seal the gap between the two roofs and adds a neat, finished look to the junction.

Step 10: Final Touches and Trim

With the roofing panels installed and the transition trim in place, we moved on to the final touches, such as installing the facial board to finish off the roof's edges. We also made sure to clean up any mess, including removing any excess screws or debris from the work area.

Conclusion: The Completed Roof

After a few days of hard work and careful attention to detail, the roof on our mobile home's back deck was complete. The finished product exceeded our expectations, and the deck now has a sturdy and secure roof to provide shade and protection from the elements.

This project was an incredibly rewarding DIY experience. While there were some challenges along the way, such as working with existing roof structures and ensuring the frame was properly aligned, the final result was well worth the effort. We not only saved money by doing the work ourselves, but we also gained valuable skills that we can apply to future projects.

If you're considering adding a roof to your own deck, don't hesitate to give it a try. With the right tools and a little bit of patience, you can achieve similar results and transform your outdoor space into a comfortable and functional area. Thanks for following along with our project, and we hope this guide helps you with your own DIY roof addition!