Upgrading floor material in new Airstreams

[Bunkroom]

TonyS posted a series of YouTube videos showing a shell-off where 1/2" PolyEthylene sheet is used.

http://www.airforums.com/forums/f36/...ork-92479.html

The video references polymax sheet polyethylene:

PolyMax Board 1/2" x 48" x 96" - FarmTek

4' x 8' x 1/2"thick is $151.97 and weighs 74 lbs. per sheet. $120 to ship 8 sheets to me in MN.

FarmTek
1440 Field of Dreams Way
Dyersville, IA 52040
USA

This is HDPE which was one option considered before.

We will have to watch for an updated YouTube video from this guy.

[danlehosky]

Bunk, mechanical air exchangers work well but also have problems. In the mid 80's lots of wood frame condos were built in Seattle and covered with Drivit an elastomeric material that is water proof. The buildings were built very tight in an attempt to conserve energy.

The buildings were attractive and sold well and were soon fully occupied. After about 6 months people began getting sick and some inside air monitoring was done and it was found that the mold and other airborn bacteria and allergens were off the charts.

A fix was thought to be outside to inside air exchangers. We looked at bidding this but declined for whatever reason I can't remember. Anyway the exchangers were installed and all was thought to be well. It turns out the exchangers were creating a very slight negative atmosphere in the buildings and when it would rain (Seattle) it would pull water in around every opening where the Drivit had been inproperly installed etc. The wood framing in these buildings deteriorated quickly and within a period of two years, the buildings were condemed and the lawsuits are still flying.

Drivit has since lost much of it's appeal in this market.

We need to consider healthy atmospheres along with energy usage as alternatives to sealing people up in plastic.

One of the last building systems I designed was the Coast Guard Headquarters on Alaskan Way in Seattle. We were told to make the building efficent but more importantly safe. When we were done the building was certified to LEED silver standards.

As energy consumption became a primary focus of design in the last two decades we have created some very unhealthy in fact toxic buildings. There needs to be a balance. Windows in large office buildings need to be able to have sash that can be opened on warm days. Naturally occuring air exchanges need to be introduced into building design. Lets bring back air shafts.

This started out to be a post about a large roll of commercial linolium I have out in my garage that I am going to template and install over the cheap ass woodgrain vinyl thats in there now but your post sidetracked me

[Gene]

Dan, a heat (air) exchanger is workable I think, just not the one in those buildings. Keeping the pressure balanced is tricky, but can be done. The RV one Bunk' found may or may not be a solution. I think the science of this has advanced in the last quarter century. I do like windows that open. With a good ventilation system, fewer windows that open would be needed and that might save money to make up for the heat exchanger.

Why not rip out the "cheap ass vinyl", seal the subfloor and then use the linoleum?

Gene

[danlehosky]

Gene, good thought. I probably will rip it out. Thats a project for next winter. The condos I referred to were multistory and had lots of surface area with little or no overhangs. I am beginning to question design based purely on energy conservation. It's not working. People are getting sick and mold contamination and remediation in hospitals is becoming a huge issue. There are no easy answers. ABS is much less brittle than PVC. The off gassing may be a problem though along with fatigue from UV rays. I thought the wood floor was sealed. Is it just raw plywood under the vinyl?

[Gene]

Yes it is raw, assuming no change between 2007 and 2012. The photos I've seen of what they are using now show a raw plywood. They are using "water and boil proof bonding adhesive". It is called Sturdi-Floor.

Gene

[danlehosky]

Ya know Gene, if I did a good job with a sharp razor knife I bet I could cut out the vinyl and use it as a template for the linolium. I could also as you stated seal the floor with some spar varnish. I wonder if you can still get that stuff. Thats what the old fisherman used on the boats. I also remember behind the sheds we had vats of creosote and they soaked virtually everything that went into a boat in this solution. I wonder if anybody ever used it on a trailer floor. There are old pilings in front of my house that were soaked in creosote that are probably one hundred years old. Still functional and solid. The state would like them to go away but can't legally burden me with the clean up.. I told them they could take them if they wanted to and haven't heard from them since.

Dan

[Bunkroom]

I started a thread about air exchangers in Airstreams:

http://www.airforums.com/forums/f427...ml#post1161145

Some action and opinions there already.

When installed and used properly, air-to-air exchange should not create negative interior pressure. Furthermore, as soon as you open the door, pressure would be balanced. They are required in homes by code in most places as well.

Back to the aluminum/plywood sandwich. I guess this is really a discussion about how to best waterproof a piece of plywood for your floor. Paint, bedliner, aluminum sheet, exterior grade finishes, vinyl, fiberglass and plastic have all been mentioned. At the end of it all, each surface has its list of advantages and dis-advantages (maybe another thread topic?).

I sincerely hope that those of you who have employed one of these methods have yourselves a 50 year floor! The technology has improved a lot in the 20-30+ years the original floors went in.

But, it is still plywood. I want an alternative to plywood that meets the 10 criteria as well as possible. The HDPE floor on the YouTube video looks great to me.

[Gene]

Dan, I used spar urethane, not spar varnish. I think "varnish" is a general term encompassing many surface treatments. Spar urethane is more specific and easy to find at big box stores.

Isn't creosote toxic? Perhaps those pilings are still off gassing and causing you brain damage? First symptoms are excessive posting on Forums followed by hanging out at the library and harassing to junior high school girls. Have yourself committed before it is too late.

Gene

[Bunkroom]

Another source for HDPE (and other plastic) panels. Looks like they have 60"X145" X 1/2" thick on sale for $205 ($3.41/sf).

The Cutting Board Factory: PolymerSheet.com


The sheet vinyl is sealing the plywood as well or better than any paint or varnish will from liquid water and water vapor that comes from the top only. The edges and bottom are still exposed and likely unsealed. Having a complete vapor barrier on one side and none on the others limits drying to the edges and bottom which are the least effective routes as they are covered by aluminum and insulation.


Real linoleum is more permeable than vinyl but not significantly and the edges and bottom of your floor are still the path of least resistance for drying. That being stated, linoleum is somewhat better than vinyl. Exposing the raw wood or coating or covering it with something that is highly permeable to allow for drying would be best if you want to preserve your floor. This way, moisture that gets into the plywood will be able to move toward dryer areas and vaporize.

Permeability: The time rate of water vapor transmission through unit area of a material of unit thickness induced by unit vapor pressure difference between its two surfaces. In Inch/Pond units, permeability is given as "perm," where one perm equals a transmission rate of 1 grain of water per hour for each square foot of area per inch of mercury (gr/h•ft•in.Hg).

[ROBERT CROSS]

Don't you love these rationalization threads...just do it.

Bob

[Gene]

I agree the sheet vinyl acts to prevent water spills from the sink, beer from the table, or whatever hits the top. But under the vinyl, water can move across the subfloor from leaks. Ours had a leak from the lower awning support next to the door and a stain going half way to the other side of the trailer. It was not close to the rot stage, but given several years, maybe.

That's why I put in flooring that I could pull up easily and look for new leaks. Since the new flooring has an expansion space around it, and trim over it, there is some breathing space from the edges.

If I were putting in a new subfloor, I'd go further in sealing it or getting something impervious to water. But I'll focus on the leaks and preventing them. That's what Airstream should have done first and then worry about the floor.

Linoleum is a good product—lasts much long than vinyl, is a "natural" product, but whether it breathes enough to make a difference, I don't know. Tiles of any substance would breath a little between each tile, but will it make a real difference? Water vapor passes through painted drywall, so things that seem solid, really aren't.

The irony of this thread is that we look for floors to solve water problems when the actual problem is a poorly sealed trailer.

Gene

[Ag&Au]

Originally Posted by CrawfordGene

I agree the sheet vinyl acts to prevent water spills from the sink, beer from the table, or whatever hits the top.

.................................................. .........


Gene

This is very useful information, as I am unusually clumsy.
Where do I place this vinyl sheet to keep me from spilling things?

Ken

[Gene]

Ken, in your case it would be best to wrap yourself in vinyl making sure it is sealed at the bottom. Also use vinyl sheets on the bed to protect the mattress. This will all make sense after the next beer.

Gene

[Ag&Au]

Originally Posted by CrawfordGene

Ken, in your case it would be best to wrap yourself in vinyl making sure it is sealed at the bottom. Also use vinyl sheets on the bed to protect the mattress. This will all make sense after the next beer.

Gene

Actually much to my sadness, I gave up drinking beer a few years back. Unknown to most people, there is a universal finite limit to the amount of beer one can consume in a lifetime. Very few individuals ever even approach this limit in their lifetime. Most of those who do, do not realize what has caused their loss of desire for beer. However one night on about my 17th or 18th beer for the evening, I suddenly became ill and upchucked about 4 or so of them. It was while in this enlightened state, that I discovered the "law of finite beer limit". I decided not to try to fight true science.

Ken

P.S. For those of you who may have noticed what profession I retired from:
Don't take this story too seriously.

[danlehosky]

I'm a very neat drinker I like scotch neat and bourbon neat as well.
Defining finite only works from a personal perspective. My finite may be different than your finite. The fact is, all finits are different or we would be infinite. I need to download some finite element analysis software called Bud Light. After several downloads I'll become reflective and continue this discussion with my thoughts on infinity. Stay tuned.

You guys are treating the symptons and not the problem.

Dan

[dkottum]

Originally Posted by danlehosky

You guys are treating the symptoms and not the problem.

Dan

Exactly, and that's the problem with this thread.

Plywood won't rot if it isn't wet, and if it does get wet it won't rot if found early. Inspect and maintain your Airstream regularly, that's the easy solution.

doug k

[ROBERT CROSS]

POI....the ENTIRE floor of our Classic was carpeted, the carpet got wet, I could feel the wet, I was leak alerted. The damage could have been a lot werse had the floor been covered with a 'noleum style product, trapping the wet beyond my finger tips. The probe on my wet meter is just long enough.....to get thru the carpet to the floor. I feel much better about not wet now.

Bob

[Max Well]

Originally Posted by dkottum

Exactly, and that's the problem with this thread.

Plywood won't rot if it isn't wet, and if it does get wet it won't rot if found early. Inspect and maintain your Airstream regularly, that's the easy solution.

doug k

I am just ready to concede that with my Airstream, as with everything else in life, perfection (in this case in the leak sealage area) in not completely achievable. Given that, I want to make it as nearly perfect as I can, both against leaks AND against damage when the inevitable leaks occur.

Nyloboard is still looking good!

Ken

[Wayward]

Originally Posted by dkottum

Plywood won't rot if it isn't wet, and if it does get wet it won't rot if found early. Inspect and maintain your Airstream regularly

Yup I have pulled all the non-visible carpet and vinyl under bunks and storage compartments to help keep an eye on things.

I grew up around and worked on wooden and fiberglass boats. Give wet wood a chance to drain and/or dry out, and it is fine. The worst situation is wood COMPLETELY encapsulated with fiberglass (floors and stringers). NO MATTER WHAT, water finds its way through the fiberglass. It usually does not find its way out, and there is no way to know until the rot has physically weakened the structure.

I also keep the "bow" of the Airstream as high as I can while stored. That way any leaks that develop, will find their way out and not sit on the floor soaking in.

[Wayward]

Originally Posted by ROBERT CROSS

the carpet got wet, I could feel the wet, I was leak alerted.

My early warning leak alert is more sophisticated and will loudly sound off "Something Smells Musty!". Last year I learned it is not wise to ignore this warning even though I smell nothing.

Every time we got home and were cleaning up, it would sound off.

"Nonsense" I would mutter, after inspecting everywhere. Finally I had the moisture detector narrow it down to the bedroom and started pulling carpet under the beds and storage compartments. Sure'nuf, a telltale stain on the plywood.

As I was replacing the SLOOOOWLY leaking toilet fill valve, the detector sounded off again - "I Told You So!"