Tiny Home Builders was started in 2009 by Dan Louche when he built his first house for his mom. Back then, he used a slightly modified standard equipment trailer for his build. After that experience, he realized there had to be a better way and set out to design a safer and faster alternative. While his design has evolved over the years, the original concept remains unchanged: to offer the best and most efficient option for tiny house foundations.
There are many different trailer types available, but only some trailers are suitable for a tiny house. All trailers are built with a specific purpose in mind. Trailer manufacturers add features to their trailers to facilitate accomplishing that purpose. The problem is, some of those features may make it more difficult to build a tiny house on. For instance, a dovetail is a great trailer feature if you plan to transport a vehicle, but will make building a house much more difficult, as well as make the house considerably less attractive.
Tiny Home Builders tiny house trailers are specifically built to build a house on. Every design decision has been made with that goal in mind.
There are a few different tiny house trailer manufacturers out there, each with their own unique design. While some of the trailer manufacturers are also tiny house builders, others are simply standard trailer companies trying to jump into a new market segment. If you end up dealing with the latter, make sure you are very well informed about what you want and need prior to ordering your trailer. Since most of these companies have never built a tiny house, nor do they have an interest in doing so, they may not fully understand how to use their own product.
We’ve come across many tiny house trailer designs that simply don’t make sense for most people. For instance, the maximum width of a tiny house that doesn’t require a road permit is 8’6”. So, some manufacturers are building their trailers to have a deck that is 8’6” wide and advertising it as having the largest buildable space. The issue is that they are not taking into consideration the thickness of the siding and any roof overhangs that may be part of your design (a common mistake with new builders). Consequently, if you bought a trailer with a deck that is 8’6” wide, you would likely either build a house that is ultimately too wide or have some of the metal deck exposed which would result in rust and water intrusion. For this reason, we rarely sell a trailer wider than 8’4”.
There are two predominant tiny house trailer styles available. The first is our default style that involves building a subfloor on top of the trailer, and then constructing the house on top of that subfloor. The second style has the trailer act as the subfloor with the sheathing installed directly onto it. While we can build either trailer style, for several reasons we prefer and build our houses on the first (much like the RV industry).
The advantage of the second style is that it provides 3-1/2 inches of additional interior height because there is no subfloor. While that is a desirable benefit, it comes at a cost. Below are the advantages of building a subfloor on top of your trailer.
By having the insulated subfloor built on top of the trailer you can maintain a consistent thermal envelope. When the subfloor is within the trailer, it is not possible to fully insulate all corners of the thermal envelope (see diagram below). Since steel and wood are terrible insulators, there is no thermal break to stop outside temperatures from entering your home. The steel acts as a thermal bridge to bring the outside temperature inside (see thermal images below). This can lead to condensation which can potentially cause mold and mildew under your flooring.
With the subfloor built on top of the trailer, you can build wider than the trailer by cantilevering the house over the sides if you choose to do so. When the subfloor is constructed within the trailer, your house width is fixed to the size of your trailer which may be significantly smaller.
By constructing the subfloor on top of the trailer, there is plenty of room for the drain lines that need to extend through the subfloor. Some of those drain lines (e.g. shower) will need to have a trap installed (see diagram below) and all of the drain lines need to run “downhill” to properly drain. Plumbing takes up space. If your subfloor is built within the trailer, this can result in very little ground clearance between the road and the relatively delicate plumbing.
While sealed underside flashing is great for protecting the underside or your house from road debris and rodents, it also has the downside of trapping any water that does find its way into your subfloor. Normally flashing is used to keep water out of an area, for instance we use flexible flashing around our windows. However, since water can often find ways into areas it’s not supposed to be in, you never want to install flashing in such a way that the water can’t escape. For instance, in our window example, flexible flashing is not installed along the bottom edge of the window so that any water that does inadvertently end up behind it has an unobstructed path to leave. If the flashing is welded to the bottom of the trailer, it can trap water which may have several negative effects such as mold and rust.
So if we don’t recommend a welded underbelly, what is the alternative? Again we borrow a page from the RV industry and use Coroplast which is a corrugated plastic (like what is used for some realtor and yard sale signs. This is screwed onto the bottom after the plumbing and insulation is installed.
While having bolts welded to the trailer to attach your subfloor may seem like a good idea, they can be difficult to work with. First, if the bolts are welded to the sides of the trailer, you’ll need to make sure that you have a joist in that exact location to attach to it. This can require you to add an extra joist or change your plans to fit your trailer. Bolts welded to the back or front of the trailer are even worse. In these locations the subfloor doesn’t typically hang over the edge, so you would have to cantilever the subfloor over the back edge just to accommodate that bolt.
It can also be challenging to work with a fixed bolt, since you will need to pre-drill the wood before putting it in place. This can be hard to line up correctly and you will need to do so before you attach the board to anything else, otherwise you will be moving your entire subfloor just to make these holes. While it can be worked around, when building a house, we would prefer not to have the extra hassle.
On our trailers we prefer to drill through the steel flange along the sides of the trailer, after the subfloor has been constructed. This allows you to put the bolts wherever your joist ends up, which is why we don’t pre-drill the flange either. While it may seem intimidating to drill holes through the metal flange, all you need is a standard drill and a good drill bit. Other manufacturers talk about plasma cutters and special drills to scare you into thinking that you can’t do it, but you’re about to build a house, what’s a few more holes to drill? For information on attaching your house to our trailers including a video illustrating how easy it is to drill through the metal on the trailer, check out our help topic on attaching a tiny house to a trailer.
We also don't recommend that you use scissor jacks. You can read about our reasons why here.
We’ve been building and using our tiny house trailer design since 2009, making us the most trusted and most used tiny house trailer in the United States. As builders of tiny houses, it’s the design that we’ve chosen to make our houses efficient, safe, and easier to build. We have never forgotten why we built that first trailer and that first house, and we continue to maintain that same sense of responsibility to our customers. You trust us to help you build your dream and we will be with you every step of the way.
We’re proud of our reputation and the quality of our trailers. We’ve been involved in the tiny house movement from the beginning, which means we’ve seen a lot of other trailer manufacturers come and go.
Recently we came across a trailer built by another company that does not meet our standards. Below are a few things to look out for when shopping for your trailer.