mold/rot fighting strategies? Anyone tried this?

[sbshaver]

One school of thought here is to prevent condensation and/or leaking, use sprayed in foam. It's out of my budget so it's out. How about creating a system of insulation that instead allows easy access to the insulation panels and other rot/mold prone areas? Make the walls and ceilings semi modular? For example use clamp in wall treatments or threaded screw holes, or whatever, don't glue anything, make a wall, ceiling, appliance, foam panel easily replaceable. Moldy area? pop it out, pop in a new one. This won't work well for those that build beautiful built in cabinets with sophisticated electronics. But for us spartans, Run conduit on the outside of the walls (the post industrial look as I call it). Make everything easy to get to. I look at these diy videos of guys cutting holes for roof vents and stuff, they don't inspire confidence really. Water finds a way in. Granted, you'll never have the killer trailer, but for sure practicality perhaps there's value? Thoughts?

Related note, I've used sharkbyte connectors for various plumbing projects with good to great results. Anyone used them in CT? It goes with the modular theme again.

[abqlloyd]

I just used shark connections for the first time on a water softener install and was surprised how easy they worked. At $20 for the fitting, it was expensive but it sure made the in-wall connection to copper easy and no soldering. I have pex equipment and the fittings are cheap.

The reality is that nothing is going to prevent water infiltration. CTT offer some of the best platforms because the structure doesn't have a lot of wood. Once rot and mold get started it's tough to stop. My plan is to minimize the amount of food. Steel frames, aluminum sidings, poly insulation, and similar products greatly reduce the chance of serious problems over the long haul.

Our last camper literally rotted from the inside, and we live in a dry climate. From the outside it looked fine. RV's twist and flex and bounce, making tight joints almost impossible, even with annual maintenance.

If I could afford it I would build an all aluminum trailer and use composite panels inside with spray foam in the walls. It would still leak.

[Mike S]

Interesting idea. If your design stays very simple, why not. You could vent it every morning when you wake up.

[OverTheTopCargoTrailer]

Cant wait to see your new design

[aggie79]

In the construction of my teardrop I was paranoid about water intrusion. My approach was to seal the exterior as much as possible and have "breathe-able" interior wall finishes. The "breathe-able" finishes would any water that permeated the exterior to leave the wall assembly as water vapor. (When not camping my teardrop is stored in the garage with the vent open and windows cracked to allow the water vapor a pathway to the atmosphere.)

[sbshaver]

Aggie what finishes did you use?

[aggie79]

Aggie what finishes did you use?

On the insulated floor of my teardrop it is bare plywood followed by foam exercise tiles and then the mattress. (This is probably not feasible for a CTC). The ceiling is bare plywood covered with a light web of high temperature spray adhesive to hold on hull liner (a carpet like material). The walls are pre-finished engineered flooring (similar to plywood). The planks are glued to the framing but the plank edges are for the most part not edge glued - I did run a 1" bead of glue every 18" or so on the edges - to leave a pathway for moisture to evaporate.

I know the surfaces "breathe" because for about 6 months or so I could smell off-gassing of construction materials and adhesives used in construction of the teardrop.

All of this said, I think the key is to have a watertight exterior.

[hankaye]

aggie79, Howdy;

When you said, "All of this said, I think the key is to have a watertight exterior."
You exclude the moisture that is created when you are inside and breathing,
granted that is a minimum of time in a teardrop, but there are days when
it rains and that itself is a day of more humidity. I'm curious about you thoughts
about moisture vapor, IMO, much more insidious than moisture in it's liquid form...

hank

[abqlloyd]

Most vapor will rise out a small rooftop vent. Path of least resistance.

[aggie79]

aggie79, Howdy;

When you said, "All of this said, I think the key is to have a watertight exterior."
You exclude the moisture that is created when you are inside and breathing,
granted that is a minimum of time in a teardrop, but there are days when
it rains and that itself is a day of more humidity. I'm curious about you thoughts
about moisture vapor, IMO, much more insidious than moisture in it's liquid form...

hank

Hank,

To us, water vapor from breathing is not an issue. In the winter, regardless of how cold the outside temperatures are, we always have a window cracked and the vent fan hood partially open (fan not on) so there is continuous air exchange and air flow. In the summer, we run the PetCool in a "closed loop" recirculation mode; however, we leave a window cracked for some air exchange. The PetCool is sized almost perfectly for the teardrop so the AC doesn't short cycle and does a good job of condensing water vapor.

On older trailers, most wood rot and mold occurs in the wood framing and exterior plywood. Often it is located around openings (vent fans, windows, electrical inlets, cargo doors, etc.), underneath surface-mounted hardware (tail and warning lights, license plate brackets, etc.) and at the profile perimeter where the roof meets the sidewalls - places where water can intrude. This rot and mold is hidden beneath the interior finish plywood that shows no sign of water damage (unless there has been a severe leak). To me, this would indicate that the problem is exterior moisture intrusion rather than damage from water vapor from breathing.

My (unscientific and unproven) thoughts.

Take care,
Tom

[chiefb711]

Vacuum seal the walls? Where there is no moisture, there is no rot.

I know some manufacturers use desiccants on the perimeter of insulated windows to keep moisture from forming in between the frames. I'm not sure if that ever has to be replaced or not...I don't know much about desiccant. If desiccant doesn't ever need to be replaced to be effective and it doesn't eat through insulation, you could add it to spray insulation and make a killing in the RV industry (Trademarked idea).

They make moisture detectors also...just take your trailer out for a weekend, and on the last day, peel back a panel and check your insulation. Just do a search engine check for "Moisture detector" and you'll see what I'm talking about.

I like the idea of a modular-type wall. With some recessed clasps and access panels, you could really do a lot. If you rivet everything, once a year you can go back, remove the panels by drilling out the rivets and then add new ones after you inspect the insulation for mold/frame rot.

I read something online yesterday saying that if you need to use a dehumidifier, the damage may already be done and you probably already have mold/rot. I think someone was catastrophizing...

Ryan

[lrrowe]

Tom, I agree with you. My wife and I sleep with windows open in cold weather while camping and do not run any heater while sleeping. ln my new CT's case, I will leave the vent in the ceiling open.

Now, I will probably have more wood in my CT then others in this forum because I went with a Car Mate trailer with 2x3 uprights and the plywood on the outside. I did this with my eyes wide open and plan on sealing all the exposed wood framing inside the trailer with some type of sealant. I will use Blue Foam inserted very tightly. All gaps and such will be filled while spray foam or clearly sealed. Then I will add a plastic vapor barrier over that. Now given my age, I am convinced it will out last me. I plan on passing it to my boys should I not be able to camp anymore and should there be an issue, they can make the necessary repairs.

Now I know this post may create many opposing views to be posted and not to sound arrogant or whatever, I am committed to my decision and not going to justify it. But just in the wildest scenario that I do get some leaks or moisture seeping into the forbidden areas, I will add all interior walls or ceilings in a way that they can be removed without destroying anything (I.e. screws in place of glue or nails, etc).


Then hopefully I can make some annual checks to make sure all is well.

And don't our forum members have a lot of experience with wood while building TD's and standies? They are managing this concern.

[lrrowe]

Vacuum seal the walls? Where there is no moisture, there is no rot.

I know some manufacturers use desiccants on the perimeter of insulated windows to keep moisture from forming in between the frames. I'm not sure if that ever has to be replaced or not...I don't know much about desiccant. If desiccant doesn't ever need to be replaced to be effective and it doesn't eat through insulation, you could add it to spray insulation and make a killing in the RV industry (Trademarked idea).

They make moisture detectors also...just take your trailer out for a weekend, and on the last day, peel back a panel and check your insulation. Just do a search engine check for "Moisture detector" and you'll see what I'm talking about.

I like the idea of a modular-type wall. With some recessed clasps and access panels, you could really do a lot. If you rivet everything, once a year you can go back, remove the panels by drilling out the rivets and then add new ones after you inspect the insulation for mold/frame rot.

I read something online yesterday saying that if you need to use a dehumidifier, the damage may already be done and you probably already have mold/rot. I think someone was catastrophizing...

Ryan

Ryan, I posted my comments before I saw your post above. I think we are on the same page also.

[chiefb711]

Ryan, I posted my comments before I saw your post above. I think we are on the same page also.

Bob,
It's all good, you are spot on!

Ryan

[aggie79]

Bob,

This sounds like a great plan!

One of these days I hope to be converting a cargo trailer. Until then I can live my dream through other folks' builds and experiences.

Take care,
Tom