To Trailer or not to build a Tiny House on a Trailer. What should you do?
Building tiny houses on trailers is a subject that I am frequently asked about and over the years I have tried to encapsulate the major sticking points to consider before jumping on that “House Wagon”.
We build houses that can go on trailers, but most people don’t need trailers this big as the rear axle is actually two cut to be shorter and narrower, so I could put them side by side. Of course the axle requires a wide load permit of its own to get home as well. Not the kind of trailer I am talking about but a good place to start. Here are a few things to consider.
First, I don’t believe in wasting perfectly good working assets and paying for them to rot before your eyes while they sit idle. The trailer that you would use to hold a Tiny House built from quality materials will be a heavy axle trailer with two axles, at a minimum. The capacity should be in excess of 7,500 lbs per axle if it is a bigger version and no less than 5,000 per axle with quality tires. This will include springs but seldom shocks and torsion control bars on the front so it is mega-important to know what you are doing with your balance of the load, front to back and side to side over the axles. There are Torsion Axles with the springs built into the axle housing in the form of giant rubber bumpers that also allow you to lower the axles and get more inside build able height while staying within regulations for not being required to permit it to move. Keep in mind that the frame of the trailer also has to be able to handle at least 10,000 lb loads but better higher because of the momentum of the mass of the Tiny House as it slams down on the trailer in bumpy or off road situations that might tilt it to one side or the other. That is when the spring capacity and tire condition really come into play to save or ruin your day.
Load balance on the ball of the trailer where it connect to the truck is vital, even more so if your truck is not as big as it should be. If you load the front too heavy and your truck is not big enough it will lift the front of the truck, wear the tires faster, make it unsafe to drive in and emergency procedure over a blowout. This is more of an issue if are not driving a dually, which means you have two rear tires on each side of the rear of the truck just in case one blow out. Likewise, if the brakes, (see below) aren’t up to par and you need to stop and depend on just the truck tires, the more rubber on the ground the better, especially in wet, windy, or icy conditions. That said, if you have not considered where all the weight in your trailer is at primarily, you could end up tongue light when traveling down the road over just adding more tools or books to the back of the trailer house. Once you drive off again the truck will feel a bit squarely, then suddenly when you hit a bump, the rear of your truck will lift up and only leave the front tires in contact with the ground for 10 or 20 feet depending on your speed when you hit the bump. I have seen trailers spin out both 180 degrees to end up running backwards into traffic with a trailer still attached and I have even seen people survive a full 360 spin without flipping, thank their Angels, over the very same issue. If you can disconnect the truck from the trailer and the tongue goes up on its own or easily with nearly no effort, you have a big problem and need much more weight on the front or less on the back. Period.
What do I mean by quality tires? The second biggest issue with building houses on trailers is this little known about set of facts. Axles do not matter if the tires will not hold a load that is rated equal to the axle capacity. Next is the date of manufacture which is on the side and any dealer can show you to prove that 3 of the 5 good years rubber has before it starts to dry out and split, then blow the tread. You do not want to buy super good priced tires on sale that are 4-5 years on the shelf in warehouses or for that matter, sitting under your house for three years not moving and having a lump on one side, sun baked rubber rotted on the sides, and have to replace them and part of the house when they throw the entire tread into the bottom of the house. Since they are steel belted tires and you peel off the steel and rubber which weigh about 15-20 pounds flying at 60 miles an hour you can imagine the damage it can do to all nearby. Why would one drive on such tires? Because they still look great for tread, just a few hairline cracks in the sides…. until they get heated up down the road that is.
Brakes, the great little package of magnets and pads that help stop a trailer if it is getting the right voltage from the truck. Assuming if they are not frozen from being parked for a years or more and not being used regularly, thus likely also having rust built up on the brake rims that keep them from getting good contact or keeping them from contracting so that they drag. This assumes they were not in an area that might puddle up around the tires regularly in which case you are likely in trouble with the rust or vines grown in, etc. Assuming you have a brake attenuator in the truck to control the charge to the brakes from 6 volts to fully engaged 12 volts which is vital to help stop it and not depend on just the truck. If not, each time you press the brake you are putting it on full blast and might even be dragging one tire to bald it in spots. If you are going to do proper maintenance on the axles before taking a trip and moving after sitting for a year or more, you might as well grease the axles when you pull off the rim and check the bearings. That working, you are ready to pull it behind a big truck, not a half or three quarter ton so that you ride the edge of the razor for capacity, get a decent truck to move it with or don’t risk the passengers lives with you if it is being the least bit hard to handle at low speeds. Test it alone… and without traffic coming at you if possible.
Other considerations include the aerodynamics of the house so that you are not just hauling a wall into the wind at 60 miles an hour then going through a mountain pass with a 40 mph wind on the other side coming at you to give the house the effect of a 100 mph wind blowing on it. Did you attach the porch light with that in mind, or the other things? Windows, doors, and accessories, not to mention the roof have to be put on with that sort of force in mind. Even a semi coming at you on the two lane at 60 and you going the other way at 60 will create a punch of air when it hits that will knock your truck and trailer over a few inches so imagine what it does to loosely attached ornamentations.
Finally, load is not just front to back, it is also top to bottom such that if you raise what is called the center of gravity too high, in other words to put the bulk of the weight above the mid point of the trailer you are increasing the risk of it tipping over in a testy situation like a jack knife in the rain, blow out on the tires, or other conditions that put a sideways force on the trailer. If the tires grab after a small slide sideways and the COG is to high, it will tip over and possibly flip your truck as well if it does not disconnect at the ball. It is not supposed to as you also have two chains to be sure you can stop it with the brakes on your truck as it flies down the side of the road laying down. Do not put heavy mattresses, books, and other things in the loft, or use a tall house plan that does not have lots of ballast and a really heavy ass trailer under it to help offset the weight of the wood, windows, siding, roof, etc that offset that on the road.
I have watched some of my Tiny Texas Houses on our trailers tip as much as 18 degrees and thought I would see them topple over but the weight of the trailer and quality of the straps saved us. Please take what I offer as advice and not an attack on those who tout building on trailers. There are many more issues still to discuss, but these are the basics that if not considered, mean all else could be for naught and people could die over the neglect of the most critical part of the process.
Now, all that said, why waste that good trailer leaving it parked under your house all the time. Get it there, lift up the house, block it and pull the trailer out to go out salvaging materials with to create, craft, make a good living, build other tiny houses with, and then slide the trailer back under it and go on down the road. If you get hassled, put the trailer back under and move it so that the clock has to start on how long you can be without the wheels before they complain again. The wheel, tires, brakes, and your wallet will all be better off if you can use that performing asset to help make a living, even if you are just getting the brokerage rights and orchestrating locals to take down the houses and barns you can get for free, you could be using your truck and trailer to make it all possible for others to get started who could not otherwise afford a big truck. After one or two salvage jobs, they will get on their feet and be able to carry one when the teachers are gone.
This is just one scenario of what can be done with the trailers if you do not trap them under houses. While I have much more to say on the subject, this covers some of the basic safety and logic issues. For more information and articles to this subject of “To Trailer or not to build on a Trailer” issue, please visit Puresalvageliving.com and become a member so as to help promote corporate influence free information on building and living in Tiny Houses.