Framing the Walls

The floor was framed, insulated, and sheathed, so was time to put up some walls. Moving and raising the long side walls isn't an easy job for one person. So rather than do them in a single 20" foot wall, I chose to build three smaller sections that I could handle myself. The downside of this was that it put more wood in the wall - which meant less insulation. The 3-1/2 inches of 2x4 stud doesn't help much, and takes away from the cavity to be filled with insulation.

This section holds the 36" doorway and a window. The header is made from 2x6s separated by 1/2" insulation. Headers built this way are plenty strong and provide more R-value than those made with plywood in the middle. I think that, in general, tiny houses are overbuilt. Nothing wrong with that, and probably a good thing since these things have to be able to go on the road. Most of the header charts I've seen don't cover the narrow roof spans of an 8'6" wide tiny house. Structurally, tiny houses have a lot in common with sheds. 

A lot of tiny houses use SIP (structural insulated panel) construction. These panels provide their strength without using studs. They get their strength from the wood sheets that are bonded to the sides of dense insulation. The building that results from using SIPs is strong and very well insulated.

I've wondered if similar advantages would come from running large headers along the full length of the sides supported by posts at the corners and a couple in the middle. The use of studs could be minimized and would allow more insulation.

Here you can see more of the wall framing. This is the front, and bay windows will go in here. You can see the door from the above picture on the left here. I liked the idea of a side door. The ladder/stairway will land close to the door.

I haven't talked about the floor plan much yet. It's amazing how much has to be decided just to frame the walls. Kitchen and bath windows have to be placed pretty accurately, since there isn't a lot of room. You start to think about where a wood stove might go. Where will the table go? What other furniture will be in here?

In my plan,the door will hinge on the right, stairs or ladder on left. The bay will be a place to sit, with storage underneath. A table or counter extension will be in front of the picture window on the right of the picture. The kitchen is in the middle. The bathroom in the back. At this point I really hadn't finalized the floor plan.

Here you can start to see the bay window take shape, gable walls, and also the loft area in the back.

When I look at this framing now, I remember that I did redo some minor things. For example, I lowered the bay window section. And once I could get "inside" and envision the floor plan a bit, I realized that a window over the bathroom sink would prevent me from having a medicine cabinet in a convenient place. So I redid that, putting the window over the toilet.

The framing is all held together with screws and glue. I think this makes changing the framing easier than if nails had been used. Screws are easily removed, and the glued boards take a little persuasion to be separated.

When I started this project, I thought using screws was a no-brainer. And I don't regret it at all. But screws, it turns out, are more brittle than nails. If you bend a screw down once or twice it will break. A nail won't break as easy when bent. But, my philosophy is that a tiny house has to be a rock because it goes on the road on occasion. Don't let the tiny house bend, and the screws won't bend. At the same time, don't use decking screws to hold your framing together. I used a lot of GRK R4 screws. Not cheap, though. Also, use an impact driver. They are noisier, but they don't twist your hand when you putting a screw in. Almost no torque, since they use impacts to rotate the screw bit. I think this is less tiring, and safer.

Framing and Insulating the Floor

Once the trailer was leveled, front to back and side to side, it was time to begin construction. 

The first step was to put metal over the trailer frame. This trailer, by Tiny Home Builders, has angle iron running along the length of both sides, and runners going the length of the trailer on which to attach the metal and the floor framing. Other trailers, utilize cross members, and it's possible to use rolls of flashing to lay strips from front to back to cover the trailer. The recommendation for this trailer is to use sheets of roofing metal. I used 29 gauge pro-panel, which probably isn't ideal. It looks nice, especially underneath with the black side down. But, a lower profile metal sheet would flatten more easily across the front and back frame members.

I did the floor framing in three sections. The middle, between the fenders, was separate from the ends. I used 2x6s which provided two inches more space for insulation than 2x4s. Nice for cold weather, but it does reduce the potential height of the tiny house by the same two inches. The trailer has a drop axle to make up for the deep floors.

You can't really tell from the photo, but the eighteen inch section at the back end is cantilevered out past the end of the trailer. It was done that way to support a full width utility cabinet and add some length to the loft above.The joists in this back section run lengthwise to provide support for the cantilever.

Similarly, in front is a cantilevered bay window area over the tongue. The triangular shape of the bay uses the space well, but still allows for sharp turns. 

The frame was bolted down with 3/8" galvanized bolts running through 7/16" holes drilled into the 2x6 frame and the angle iron. The bolt head and washer were recessed below the surface, and filled with epoxy. Once the floor sheathing is put over the top, the epoxy around the bolt head will help keep it from turning if it should ever require tightening. But the bolts are long enough that you can get a vice grip on the end of the bolt while tightening the nut, and the nut is secured with Loc-tite thread sealant as well. 

To fill the cavity left by the 2x6 framing, 5-1/2 inches of insulation was required. I used R-Tech rigid insulation from Home Depot. It took two thicknesses of 2-inch insulation and two thicknesses of 3/4-inch insulation. That filled the 5-1/2 inches and gives the floor about R-21. 

Decisions, Decisions...and Finally a Trailer

It has been quite a while since I last published, but rest assured that I am well into the process of building a tiny house. After looking at the plans, and considering the advantages of each, and not really finding what I wanted, I decided to do my own design. No doubt the plans that I have reviewed will all influence the tiny house I build. More on this as I publish my progress.

My first purchase was a 20 foot trailer from Tiny Home Builders. It took just over a month for the trailer to get built, and then on September 1st I picked it up with my 2001 Mazda pickup in Logan, Utah. Logan is about 500 miles from my home in Arvada, Colorado.

Here is the pickup and new trailer just east of Logan. This was the prettiest part of the trip. My route home took me through southern Wyoming, across the continental divide, twice each way to be accurate. Much of southern Wyoming is in the Great Divide Basin, with the continental divide split on each side. Water in the basin normally stays there and can't flow to either the Atlantic or Pacific. The trailer was all my 4 cylinder pickup could handle on the long climbs. At 8 ft. 6 in. in width, the trailer was much wider than the pickup, and required some extra attention to keep it centered in the lane.

After getting it home, I managed to back the trailer into the work area, and start to level it.

So there it is, the foundation to my tiny house.