UPDATED: July 21, 2012 (see additional Facebook comments from brad at bottom of original post!)
Recently, one of our readers sent in this question:
I love tiny houses. This includes tiny houses built on trailers. In fact, I’ve recently made a deal to acquire a travel trailer to rebuild for this purpose. What amazes me is that very, very few people, when designing these homes on trailers, pay any mind whatsoever to airflow and other factors that would make towing easier and more fuel-efficient. Why is this not a first priority consideration in these designs??? Can someone from Tumbleweed Tiny House Company or Tiny Texas Houses elaborate?
Here’s Brad’s answer:
I Do Not build houses to be towed down the highway on a regular monthly basis and nothing I have built so far is likely going to be pulled with any ordinary family truck — even for Texas and we like 1 ton Dually Turbo Diesels with gooseneck hookups. My custom built trailer for one of my bigger houses will take the bumper off a normal truck or lift its front tires off the ground if you try to gun it.
I have considered one for my personal use and I agree with you, travel trailers should be designed differently than portable houses. Add to the mix my insanely heavy Long Leaf Pine (4 lbs a board foot) and Loblolly Pines (2-3 lbs per bf) the base weight is outside the realm of fuel efficiency but also beyond the weight capacity of any typical truck. My smallest houses come in at 8,000-10,000 lbs but weight is not my concern. They travel 65 mph down the highway when we transport at 5-6 miles per gallon perhaps a bit less on a big one or into a wind, but still, not bad for pulling 18,000-25,000 of house and trailer down the highway. Now with a team of horses and a good front and rear axle rigged trailer, we could still pull off moving them as they did in the 1800s, but not at 60 mph. The point is we still could.
As to people building them and using them to run down the road a lot. Weight, pieces falling off at 60 mph, cross winds, driving into winds affecting true wind pressures and likely lack of consideration in construction will eventually lead to disastrous results, in my humble opinion.
I have issues with using inferior new woods that are structurally suited for holding nails well let alone screws but the use of plywood, particle board, and other synthetics with numerous chemicals outgassing for the initial period of a year or two is also an issue that will come up with the extremely tiny houses you are speaking of as there is much less air inside compared to the surface areas and parts of many of the new material homes. That creates an exponentially more toxic soup until it is aired out.
As to aerodynamics, it is hard to beat an Airstream and you can buy an incredible shell with a great suspension system, for far less than you could ever hope to build an aerodynamic shell that would be tight, hold together under the extreme twisting, banging, and multiple forces that will tear at a house that is moved very often.
Likewise, size limitations for pulling without permits in different states vary, as well as how they need to be equipped for lights or other details. The vehicle weight is critical as well as the rubber on the road, the brakes on the trailer, reliability of the weather, and tongue weight. I have seen several vehicles spin out on the highway from having a tongue weight that was too light, in other words a rear weighted trailer and they end up in wrecks when they hit a bump at over 50 miles an hour and the rear wheels lift off the ground so your front wheel have your only brakes (!).
That very problem cost me a truck over a negligent employee in one case but thankfully no one got hurt as he did a 180 degree spin across lanes to tail end the trailer in the guardrail on the opposite side of the road. This is a nasty mistake most people do not even know can happen. There is way too much ignorance about pulling heavy things down the road to add into the mix the huge chance that someone will not understand axle placement, spring capacities, tongue loads, flexibility of materials and fasteners as well as the quality and life of the fasteners in extreme conditions, like near the beach for a month or two.
I predict some worrisome outcomes before people start to take seriously the issues with building houses that will travel frequently on the road — pulled by people who do not know what they are doing with vehicles that are not equipped to pull, let alone stop quickly, if anything should go wrong. I am not on that boat, bus, or taxi.
I hope that takes care of my position. I build houses that will last for a century or more, is nearly toxin free, heavy as can be so as to hold a nail, screw, or heart for the rest of time.
Thank you for the opportunity to expound and answer your question.
~ Brad Kittel
Tiny Texas Houses
My Additional comments to my TTH Facebook Friends…
Then we go to the other end of the load. What is the load capacity for the ball and how they are attached to the frame, rather than just the bumper, how stable is the load if they did not get the upgraded tow kit, the beefed up tow ball and perhaps, make sure the brakes on the trailer are working or one will jack knife or hydroplane if the load exceeds the friction of the tires on the rear of the vehicle pulling it. These are issues most people do not even know to question and anticipate the dangers, unlike truckers who do live with watching the results of poor planning or control of heavy trailers end people’s lives on a regular basis. Even with my houses, we have had a tire blow and the tread take out the fenders on the trailer throwing all sorts of steel on the road. The tires werre simply over three years old, and rubber tires have a limited life, much of which is spent on the shelf before someone gets a really good deal on old inventory that looks new. Check the manufacturing dates and get them fresh. This I know from experience.
Moving things only once every few years and never otherwise does not instill the best of habits and mine is only a cautionary note based on having seen so many problems. We have had tires that look perfectly good peel off with a half inch deep tread still on the tire when it happens. With 8 big tires across the rear of my trailer we can lose one or two and still stop safely. For smaller trailers with the 3,500 -5,000 lb axles with cheap, outdated rubber, worn, or simply under rated tires will also lead to major problems if someone is going for cheap as a guideline. The sidewalls blowing out will topple a high center of gravity load especially when the driver reacts and pulls off to the shoulder increasing the angle of inclination and potential for a rollover, especially with top heavy loads, ergo, tall, narrow, high center of gravity, and only two tires on each side so that when one goes out, the second tires can not hold the load by itself because it was at capacity to begin with, thus the passenger side is extremely prone to tipping into the ditch when one pulls over and stresses out the remaining tire on that week side. It happens with travel trailers all the time even thought they are built with much lower centers of gravity than a lofted plywood home with cabinets on the wall and a relatively lightweight trailer.
Just to make this worse without doing anything but taking out a different tire in a blowout and suddenly with a single set of tires on the back of the truck pulling a trailer blows and if the trailer brakes are not working right, slamming the brakes in any way could jackknife the pair in a second on a slippery road of any sort unless you are an experienced driver who will not panic with a semi next to you when it happens. These are not fantacies as I have personally survived a variety of these blow outs and lost tires as well as having my father loose his travel trailer and watch it shred itself over a half mile of highway with all of their belongings strewn along the way. When ever we push the limits of what our vehicles can do and the drivers are not prepared for the worst scenario, we are not just taking our own lives into our hands but also those who will meet with the consequences of our failure to consider these issues in advance of embarking on a grand escapade with a homemade house on a trailer behind you.
I am sure the tales of houses will follow, but if we are at least aware that these are all issues to watch for then we can be prepared, look for the signs of issues, and dodge the bullet that could come from negligence, stupidity, or ignorance on the road. I do not build road houses for people because I can not imagine the liability or the blame that would come to me if someone down the road did not pay attention to these things and something went wrong. Who’s fault is it? I don’t want to be in the group that gets considered for inclusion by the attorneys or the family of the deceased so I tread very carefully on advising, designing, or creating roadhouses that people imagine they can just go from back yard to back yard of friends for years to come.