c. building a unit from the frame up
I’ll talk about each in turn.
b. refurbishing a unit to make it safe
Finding a tolerable unit from the start
This usually presupposes only mild MCS, as nearly all units have carpet, foam, and other toxic materials. Because molded fiberglass units tend to have the wood subfloor sandwiched between two pieces of fiberglass in a vacuum seal, some believe these are the safest kind of unit to purchase. There is a lively market in used units, and people say they hold their value. Some brands are Scampi, Casita, Eggcamper. People have asked to spend a night in the potential unit to make sure they can tolerate it. Some owners are willing to do this, but only when they aren’t deluged with callers who don’t have special needs!
Disadvantages: They are all trailers, and tend to be quite small, 10 – 17’. The space, while sufficient for a single person, is a challenge for two people. Think about squeezing a kitchen, dinette, and bathroom into your bedroom and you’ll get an idea.
Plastic (fiberglass is a plastic) is electrostatic and tends to suck up toxins like a sponge. Sensitive people say it gets contaminated and can’t be saved. Think of the way a plastic food container smells after storing tomato sauce. The harder plastics absorb less, but do they ever get to 0%?
I also consulted with Earthbound, who won awards for their 'green' construction, They sound promising, but I can't go to Marion, IN to check one out, and they don't yet have dealers around the country. For more information, talk to Jon at
The other 'green' RV I visited was a Coachman Freelander. It didn't smell bad, and the salesman let me spend over an hour inside it. The flooring is some kind of non-toxic linoleum and the cabinet doors are real wood. I probably could have made do with it, but it felt cheaply made to me, and the price tag was nearly $50K, and I didn't trust the fake materials, whether formaldehyde-free or not. Whatever is being use to replace formaldehyde could turn out to be just as much of a disaster as the formaldehyde.
Some questions to ask in purchasing a used RV
1. Pesticide use?
2. Smokers inside?
3. Cats or dogs?
4. Any history of roof or plumbing leaks?
5. Ever find mold?
6. Ownership history?
7. What product do you use in the blackwater and greywater holding tanks?
(most use odor reducers full of formaldehyde – only good one is Odorlos; others dump daily and rinse tanks. Kristi says the half-life of formaldehyde is 5-12 years, so it’s useful to have a full maintenance history.)
Refurbishing a unit to make it safe
There are three strategies here. The most extreme reactors start with an aluminum frame cargo van or cargo trailer, strip out the wood and make it into a non-toxic shell before they add whatever minimal furniture, tanks, and conveniences they need. Less extreme reactors start with a conventional unit, remove toxic items, and seal porous items.
Extreme reactors – MECU (mobile environmental control unit) invented by Erik Johnson
After having four conventional units go moldy on him, Erik Johnson discovered how to make a livable unit that would not go moldy and would be easy to decontaminate if necessary. He started with an aluminum-framed cargo trailer, stripped the wood from the walls and subfloor, and put in several inches of polystyrene foam insulation. He uses the foam as his interior wall, but also suggests installing an aluminum skin over it. Because the foam outgases in the heat, he set up a permanent rack on top that provides shade. To avoid toxic sealants and caulks, he put in windows that are screwed down tight with a rubber strip under the lip. The small air gaps help provide air exchange when the trailer is closed up. He uses a wood stove inside for heat during the cold months. He does whatever he can to minimize condensation inside the unit . He keeps his space safe by decontaminating when he returns from trips through congested areas and buildings-- places he cleverly calls “civildevastation.”
On the suggestions of friends, I looked into having something like this build by two companies that make all aluminum cargo trailers, Carson and Aluma. This is not a price comparison, as I asked for different sized units from each company. All would be custom build with no wood anywhere, no sealants, adhesives, tape or silicon, following as closely as possible the guidelines Erik had found safe for himself, and which City Changer had found successful after reacting to the caulking in a pre-built all aluminum trailer. The floor would be made of interlocking plank and the walls would have uprights tubes as support. An aluminum skin would hide the foam insulation.
The largest unit I asked about was an 8.5’ x 18’ trailer with V nose (adds another 1 ½ to 2’ at the front end, with two windows, a side and rear door, 30 amp electrical service, a 6 cu foot refrigerator, a 12 volt battery, a ceiling AC unit with heat pump, 40 gallon grey and black water tanks, 50 gallon fresh water tank, sink, toilet, and outside shower. Total cost $17,000 by Carson. The unit would weigh too much (7000 lbs) to pull with our F 150 pickup (max 3500 lbs) so we’d need a new truck.
Aluma quoted these prices for a bare shell without tanks, toilet, or electric, just the trailer with foam insulation and aluminum skin
7 WIDE X 18 LONG PLUS A 3FT VNOSE-$11,400
WIDE X 24 LONG PLUS A 3FT VNOSE-$18,095
In addition to price, another disadvantage of an all aluminum trailer is that EMF sensitive people can’t tolerate much metal. I’m not sure about this for myself. I’m sensitive enough that I can’t sleep anywhere near a transformer (I discovered that my first night back at Sam’s Hot Water Spa) and I get pains in the my hands whenever I’ve tried to use a wireless mouse and pain in my ear from some cellphones. I’d sure hate to pay to have something built only to discover it intolerable.
To sum up, the advantages are: no wood, no plastic, no caulks and other VOC's, easy to decontaminate, freedom to furnish any way that works for you.
Gutted and rebuilt Airstream trailers
Tad and Justin Taylor’s strategy has been to gut and replace everything in a trailer with inert materials. This is involved and expensive, and uses the same approach as gutting and rebuilding a permanent house with inert materials. The Taylors do this work with used Airstream trailers and sell them from Brattleboro, Vermont at http://healthy-homes.com/ Their stuff is incredibly beautiful. However, if you decide to go this route, ask for samples of the materials. One of my sensitive friends could not tolerate the flooring.
Another strategy of moderate to severe reactors is the fix up a conventional trailer. Credit for developing this process goes to Jeff Crowley, with thanks to my friend Scott for sharing details of the process with me and allowing me to tour two renovated-for-MCS trailers.
Step 1: Finding a suitable unit to revamp
a] ideally 7 – 10, maybe 12 years old (enough to outgas, not enough to fall apart if well cared for)
b] something that’s been in a dry climate all of its life (reduces mold risk)
c] no issues with mold or water intrusion
d] no unpleasant odors
e] solid wood cabinet doors
Step 2: Have it inspected by a competent servicing company for any water intrusion and any system issues (plumbing, electric, mechanicals if a motorhome, fridge) before purchasing.
Step 3: Verify that pricing is fair through nadaguides.com.
Step 4: After purchase, have all the windows and seams completely resealed by a professional before taking possession. Scott warned me
“do not attempt to do this yourself with some sort of ‘safe’ caulk as it will NOT keep water out for long! You must use the right sealants, and not to worry --they do cure quickly and don’t smell after a few days. Failure to ensure that the unit is well sealed from the beginning will ruin even the best remodeling job.”
Step 5: Strip and Remove :
- Remove and dispose or all furniture (not cabinets, but bed, tables, couch, etc. This is all toxic and must go if it has foam or any fake materials that could outgas.) (One person successfully covered the bed in TuTuff and got used to the sound of crinkling plastic when sleeping)
- Strip floors to the plywood subfloor.
- Remove carpet from walls, ceiling, cabinet interiors – carpet holds dust, even if regularly vacuumed, and dust contains fungal DNA which can cause reactions. It also holds odors and moisture.
Step 6: Clean and Seal
- Clean everything thoroughly with non-toxic cleaners to remove every trace of dirt, dust, and odors
- To make any RV safe when going down the road, so you don’t get dust, mold, and fumes inside, you have take out every light fixture and seal around the edges, same with all the pipe fittings and such, as there are usually small leaks. Jeff uses electrical and then oil tape.
- Cover plywood subfloor with Tu Tuff and foil tape.
- Seal off interiors and exteriors of all cabinets (not exterior wood doors). Scott used aluminum foil and foil tape to get rid of formaldehyde in the pressboard, but said one could also use Tu Tuff if you don’t want foil.
- Because wood absorbs odors and moisture, seal all wood surfaces with Weldbond.
• An alternative to Weldbond is real shellac to seal all the wood surfaces.
- From Wikipedia:) Shellac is a natural bioadhesive polymer and is chemically similar to synthetic polymers, and thus can be considered a natural form of plastic. It can be turned into a moulding compound when mixed with wood flour and moulded under heat and pressure methods, so it can also be classified as thermoplastic.
- o Shellac scratches more easily than most lacquers and varnishes, and application is more labor-intensive, which is why they have replaced shellac in most areas. But damaged shellac can easily be touched-up with another coat of shellac (unlike polyurethane) because the new coat merges with and bonds to the existing coat(s). Shellac is much softer than Urushi lacquer for instance, which is far superior in regards to both chemical and mechanical resistance.
- o When dissolved in alcohol blends containing ethanol or methanol, shellac yields a coating of good durability and hardness.
- o Shellac is UV-resistant, and does not darken as it ages
- If desired for extra safety, seal all walls and ceiling with aluminum foil or Tu Tuff and wheat paste plus foil tape.
- Paint all walls, exterior cabinetry (ir pressboard, not if solid wood), and ceiling with Murco M 100, a completely inert clay paint. Keep all windows open while painting and for at least one week afterward to ensure complete drying and offgassing. Do not paint when rain is forecast.
- Some people say they’ve successfully used Bioshield as a sealer.
Step 7: Lay porcelain tile (not ceramic—not strong enough) down flat over the Tu Tuff. Don’t use thinset and grout, it will crack in transit unless you use brands with toxic plasticizers.
Now your RV is ready to become your living space.
One of the trailers I saw that was done like this was so beautiful that I decided to include a picture of it. It’s so much nicer than any of the prefab ones out there, unless you happen to be a wallpaper fanatic.
Building your own RV from the ground up.
I haven’t looked into this in as much detail, other than getting estimates from Carson and Aluma for wood free units (see above), but I did find some stories on the internet of people who have done this successfully.
There is an interesting option called the tortoise shell house, which advertises as “the high quality, low cost mini home.” They are built on wheels and there are several models available which you can see at http://tortoiseshellhome.com/index.html.
The floorplan of the Box Turtle is a smart use of interior space for a 17’ trailer.
The company now offers a 28 foot model that gives you a separate bedroom, and loft storage, called The Snapper:
Don’t get too excited though. These houses are not free of wood, and thus potentially problematic for us mold sensitive types.
However, one can purchase the Galapagos model which is just a steel frame on wheels and allows you to build the walls any way you want. It includes a shower enclosure and faucet. The company says the frame is lighter, uses 30% recycled materials, and can be completely free of hookups by solar power and a high tech water treatment system that uses river or lake water for most of your water usage. One makes a 120 sq ft house, and two can be combined together to double the space.
I learned about places that build RV’s custom and offer to use non-toxic materials:
1. Richardson's RV Centers have created a new "Build Your Own RV" division for its customers across the United States. Not only can you build to the exact specs desired online, you can choose the colors, options, and features you like best. Don't know if they can use non toxic materials or not. http://www.buildyourownrv.com/
What kind of construction is best?
I thought laminated construction with an aluminum frame was the way to go until I spoke with a dealer who handles Excel trailers and fifth wheels. Excel is considered the top of the line for fifth wheel trailers (also known as gooseneck trailers) as their units are built to withstand temperature extremes down to -10 degrees Fahrenheit. The reason this company sticks with wood is explained on their website.
Wood is a natural insulator, while aluminum frame coaches transfer the cold from outside to inside, thus allowing condensation to form when that cold outside air meets the warm, humid inside air. It really doesn't matter how thick your aluminum wall stud is, it can be the standard 1 1/2" stud, 3", or even 6" (For illustration only) and whatever temperature the outside of that stud is, it's going to be the same tempurature as the inside, next to your paneling.... creating condensation.
The issue of condensation is the main source of problems for us mold-sensitive folks unless we have a totally wood free unit. But with luan wallboard (a thin plywood or pressboard) product on the inside of walls and ceilings, the condensation gets transferred to the wallboard from the back side, and this (even without water leaks) can lead to the growth of mold. The salesman explained that with polystyrene foam insulation, condensation can occur on the foam and lead to small amounts of mold growing on water droplets.
The website addresses this issue:
Wood rots and aluminum doesn't! Of course it's hard to argue with that one. We have found the secret to this age old delema is to keep the water out. With today's one-piece fiberglass sidewalls, one piece EPDM rubber roof, 2 piece gel-coat fiberglass roof, combined with the best sealants ever, keeping the water away from wood isn't as hard or tricky as it once was.
I thought I knew what to get and now my head is dizzy with indecision. I liked the Lazy Daze Class C RV's that I saw on lots, but after I went to the factory in CA and saw how much wood was in the frame, I decided to look for a product with aluminum frame and laminated walls. Now I'm circling back again.
Other products people have safely used:
a. Butyl tape
b. Coating wood with magnesium oxide, which doesn't mold.
c. wool insulation sprayed with clay dust to dry it out further as it is already mold resistant and doesn’t outgas as much as polystyrene solid foam
d. Silcone caulk with Microban (an antigungal).
On the differences between laminated compared to stick and tin sidewalls on rvs, there is a funny video at http://www.youtube.com/watch?v=0dZp2B_mmow.
The disadvantage of the laminated wall structure is that if a leak occurs, water will seep into the luan wall board and it’s expensive to have it repaired.