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In the last part of our build, we skinned and sealed our rear hatch door. In this part of our series, we’re going to do almost the same thing for your roof assembly. However, we will be adding a sheet metal layer as the outer skin, a hurricane hinge to connect your hatch door to the stationary skin and “J-Rail” or “T-rail” along the roof to control water flow and drainage in the event of rain or snow.
Timing & People Needs
1-2 days. This is a lengthy project, and frankly one that you should take your time with. Plan accordingly.
2 people needed. You need someone to help you place the insulation and hold everything in place while the other person fastens materials to where they need to go.
Materials You Need
| Material | How Much You Need | Cost Range | Where to Get It |
|---|---|---|---|
| Contact cement | 1 can | $$ | Home Depot |
| Wood glue | 1 bottle | $ | Home Depot |
| 1/8″ x 4′ x 8′ plywood | 4-6 sheets | $$ | Home Depot |
| 8-mm sheet metal | 1 sheet | $$ | Home Depot |
| #8 1-7/16″ wood screws | 1 box | $ | Home Depot |
| 44″ hurricane hinge | 1 hinge | $$ | Amazon |
| 94″ pieces of J-rail or T-rail | 3 pieces | $ | Vintage Trailer Supply |
| 1″ wide butyl putty tape | 1 roll | $ | Amazon |
| 1/2″ wood dowels, 4′-5′ wide | 4 dowels | $ | Home Depot |
| 2″ all-purpose wood screws (2 per spar) | 1 box | $ | Home Depot |
| 4′ x 8′ x 1/2″ foam insulation board | 2 sheets | $ | Home Depot |
| 4′ x 8′ x 1″ foam insulation board | 2 sheets | $ | Home Depot |
| Construction adhesive | 1 case | $ | Home Depot |
| 2″ x 2″ boards (for spars) | 8-10 | $ – $$ | Home Depot |
Tools You Need
| Tool | Cost Range | Where to Get It |
|---|---|---|
| Utility knife | $ | Amazon |
| Power drill | $$ | Amazon |
| 2-1/2″ paint brush | $ | Amazon |
| 4″ putty knife | $ | Amazon |
| Table saw | $$$ | Amazon |
| Rolling pin | $ | Amazon |
| Chalk line | $ | Amazon |
| Soft tape measure | $ | Amazon |
Cost of Skinning Your Roof
For materials, this part of the project will cost you about $350-400. We’ve used the tools I listed here in previous steps, so you should have all of those already.
How To Skin Your Roof
Installing Your Roof Spars
You may recall that in a previous tutorial we recessed a 1-½” inch wide ledge on each side of your trailer at 2-1/16″ inches. This is where you will lay in your spars leaving you with a 7/16″ inch gap which will be filled when you lay in the four sheets of 1/8″ plywood just as you did for the hatch door.
The first spar you should install will be the spar that is closest to your hatch door. Put your hatch door in place and make a mark on the walls where your hatch door gussets end. At this point, you can remove the door and set it aside while you continue to work on the spars and skin of your teardrop.
Once you have done this, measure ¼” inch on the outside of your door gusset mark (toward the front of the camper) to create a gap where your hurricane hinge will rest once it is installed. Now measure the distance from the inside of your walls and this will give you the length of your spars. Install your first spar flush with your two marks, remember to apply construction adhesive on the side of the spar that will rest on your inner ceiling. Now, from the outside of your walls, secure your spar in place using some 2″ inch wood screws.
Repeat this process for each spar. I recommend installing a spar every 12″ inches on center. However, if you are installing a sunroof or ceiling fan, you may have to adjust for these openings. Also, when you reach the front of your teardrop with the tight radius corners, you’ll need to install a spar every 3-4 inches in that area to ensure that your skin will conform evenly around that radius. Remember to add adhesive and secure each spar with your 2″ inch wood screws from the outside of your walls.
Installing Your Insulation
Now you’re ready to install your insulation. Measure the area between your spars and drop one piece of ¾” inch foam board and one piece of 1″ inch foam board in these openings.
Note: Do not glue the insulation in place. Some glues will deteriorate the insulation and if you ever need to make a repair, you’ll find that easier if the foam isn’t glued in place. Also, between the radius spars, the foam board will need to be cut with a taper to fit in place.
This is also the time when any holes for electrical wiring that may go to an overhead light or exhaust fan should be drilled and its wiring secured.
Skinning Your Teardrop Camper
Now that you have laid your spars in place, prepared for wiring and installed your insulation, you’re ready to start the process of skinning your build. First, take your soft tape measure and measure from where your hatch door seam will meet your wall in the front of your camper.
Is this measurement under 96″ inches? If it is then you can cut and lay four layers of 1/8″ plywood skin without having to adjust for seams. On the other hand, if your skin is over eight feet in length and you need to lay it with seams, always remember to stagger your seams between layers to maintain the integrity of the overall skin. Never cut each layer the same length and install them like that. This will cause a serious structural problem that will result with that part of your skin constantly moving while in transit.
Instead, stagger your skins if they’re more than 96″ inches in length and if you find that each of them is a close measurement away from the other, stagger the seams by cutting one layer short and the next layer long. In other words, leave a distance or 16-18 inches between the seams of your skin. This will ensure the integrity and the strength of your skin.
Now you’re ready to install the first layer of your outer skin. Apply construction adhesives to your spars and your ledge and lay in the first layer of your skin. I recommend using some temporary screws and fillers per layer just as we did when we skinned our hatch door in a previous article. Once you have done this for the next four layers, we’ll move on to securing our sheet metal skin.
Adding your outer skin of metal can be tricky. Personally, I recommend searching locally for a company that can custom cut your outer skin to your specifications. In my design, I have included a sunroof. How am I going to cut the last skin of metal for that design?
I’m going to install the metal skin, then call an expert that specializes in dealing with that type of metal and I’m going to pay that person to cut out that opening correctly. Frankly, I don’t have the knowledge or experience to deal with this part of the build, and I’m going to pay for a craftsman that does.
Securing Your Metal Skin
That said, the next step in our build is to secure the metal roof to our wooden roof skin. For this step, we’re going to need contact cement, a putty knife and a few dowels and a rolling pin.
First, lay your metal outer skin and make sure it’s cut to fit. If you’re satisfied with how it fits through the radii and straight measurements of its installation, set it aside and begin the adhesive application on the wooden inner skin and the outer metal skin.
Apply contact cement on both sides and allow them to cure and become tacky. Once they are ready to join, lay out the dowels to keep the surfaces separated.
From the center, carefully move the dowels outward and apply pressure with the rolling pin to seal the outer metal skin to the wooden skin. Secure these layers using temporary screws and repeat the process as needed.
Now that we have secured our outer skin to our outer walls, we’re going to install a very bendable rail that will hide those seams and the screw holes.
As a rule, I recommend that each screw hole be placed approximately 4″ inches apart but in a tight radius you will need to shorten that distance.
For this build, I’m going to install this rail on the top of my skin. It’s easily bendable and it will mesh well with the outer wall’s aesthetics. Although it’s not a pre-drilled fixture, I’m going to drill a 7/32″ pilot hole every 4-5 inches and secure it to the outer skin in it’s longer and flatter surfaces. For the tighter radii, we’ll shorten those measurements.
In the next part of this series, we’ll look at some final steps for wrapping up our build and we’ll also look at how we’re going to license and properly register or plate our homebuilt camper to make it legal and roadworthy when you travel.
Until then folks, thanks for following and as always…I hope to see you out on the road sometime.
Start reading step 10: wiring your trailer navigation lighting
