I doubt you'll do damage to them as long as you don't have real extremes.  High humidity could be a problem, that you should try to avoid.  Where do you live, how big a temperature swing and humidity swing are we talking about?

It’s the Humidity that will harm them most. Moisture in the air. Extreme cold could harden the rubber parts. Be more concerned with the water vapor in the air in the space they occupy.  In my humble opinion.

Yup, what John said.  I live in New Orleans... humid as all get out.   How big is the shop... and, is the shop insulated?  A simple de-humidifier may work very well. They are inexpensive and do not consume much electricity... run a small drain line to the outside and you will not have to empty the water collection receptacle.

@gunrunnerjohn posted:

I doubt you'll do damage to them as long as you don't have real extremes.  High humidity could be a problem, that you should try to avoid.  Where do you live, how big a temperature swing and humidity swing are we talking about?

I live in central Oklahoma, near Tulsa to be exact. Not too bad humidity wise, but we do have crazy temperature swings. Sometimes we'll be in the high 90s one day and low 70s the next, we never know.

@Dennis-LaRock posted:

Yup, what John said.  I live in New Orleans... humid as all get out.   How big is the shop... and, is the shop insulated?  A simple de-humidifier may work very well. They are inexpensive and do not consume much electricity... run a small drain line to the outside and you will not have to empty the water collection receptacle.

It's roughly 30 x 30' with some plastic insulation I do believe.

Looks to me like Tulsa is one of the better locations as it's fairly dry (annual precipitation 16.61").  Temperature swings seem relatively moderate as well.

Is there an interior wall and ceiling covering in the shop... i.e., can you 'see' the wall studs/roof rafters (no interior wall/ceiling covering) or are the studs/rafters covered with Sheetrock/paneling or some sort of sheet plastic?   You may want someone to take a look at it for you to determine how 'tight' the shop is.  If the walls/ceiling is covered... it probably does not need to be insulated because Tulsa is pretty darned dry with a very low average annual humidity.   All that said... I would have a dehumidifier installed.

Here is a dehumidifier example... key points ...50% larger than the room sq. footage, Drain Hose Outlet, Auto on/off.

hOmeLabs 22-Pint Dehumidifier $159.99

Odd,  because hobbyist have been running their trains, in attics basement's, sheds garages and even outside for over a hundred years.   You adapt and overcome

Different folks have different comfort levels and experiences.  The Op's concern is legitimate and he probably would like eliminate any potential pitfalls from the get go.  When I picked up the 2046 set from my parents basement in Vermont around '85 I found the track quite rusted and the cast, commutator and linkages heavily oxidized when I got it back to NYC.   On my next trip to visit my  parents I installed a dehumidifier in their basement for which they were quite grateful.

@Dennis-LaRock posted:

Different folks have different comfort levels and experiences.  The Op's concern is legitimate and he probably would like eliminate any potential pitfalls from the get go.  When I picked up the 2046 set from my parents basement in Vermont around '85 I found the track quite rusted and the cast, commutator and linkages heavily oxidized when I got it back to NYC.   On my next trip to visit my  parents I installed a dehumidifier in their basement for which they were quite grateful.

agreed. but any environment can be overcome!  Not everyone has a climate controlled room , for our pikes.  Every situation and location is  different and the fix can be simple or extreme . I have built layouts in basements, attics,  barns, and in the garden!  most any situation can be delt with.     PS Damp basements are horrible ,the dehumidifier is a plus, along with goo ventilation!

I have a walk-out basement, but I still have two 70pt dehumidifiers to make sure the humidity doesn't get out of hand.

Over dehumidifying is not an ideal situation.  Dry air absorbs water, so you can actually draw humidity laden air through the walls of the basement and force unnecessary running of the dehumidifier. invest in a quality humidity meter and maintain about a 50% level.  Don't rely on the meter or settings on the dehumidifier as they are not that accurate.

50% ! Egads I would suffocate! Humid days here are around 10 to 12%! I don't worried too much about rust or electronics here, but traction tires and wire insulation needs to be paid attention to. And I don't run trains outside, the UV here will dissolve them in no time, LOL! And no basements here in central Arizona unfortunately.

@CSXJOE posted:

Over dehumidifying is not an ideal situation.  Dry air absorbs water, so you can actually draw humidity laden air through the walls of the basement and force unnecessary running of the dehumidifier. invest in a quality humidity meter and maintain about a 50% level.  Don't rely on the meter or settings on the dehumidifier as they are not that accurate.

I run my dehumidifiers at 40%, which is more than sufficient moisture in the air.  I have to disagree that the dehumidifier readings are that inaccurate.  My two humidity sensors track the dehumidifier settings within 5%, which is more than sufficient.  Also, higher humidity settings in the basement can contribute to mold, something you certainly do not want!

A few references on optimum humidity settings.

Dehumidifier Setting Chart: What Should Dehumidifier Be Set At?

It might be that 50% would be enough. However, at higher temperatures such as 80°F or 90°F, the likelihood of mold growth is significantly increased. To negate this, it’s always safer to set a dehumidifier setting to 40% to prevent mold growth.

How to Get the Most From Your Dehumidifier

Set the humidity level. The optimal relative humidity level is between 30 and 50 percent, according to Energy Star (and 30 to 40 percent in colder areas during heating season). If the humidity is higher than that, it can breed dust mites, mildew, and mold, and trigger allergies.

How Should I Set My Dehumidifier In the Summer?

But at what relative humidity setting should you set your dehumidifier? You should set the relative humidity (RH) level of the dehumidifier between 30 to 50%. Many people reported 45% as an ideal relative humidity level. This percentage can be increased or decreased depending on your comfort level and your home’s needs.

I prefer my Sputnik temperature, relative humidity, barometer to the newfangled SENSI thermostat that runs the heat pump.

Sputnik 42% Relative Hydro

SENSI 49% Humidity

For wood flooring, if you have a mfg warranty claim and upon inspection your moisture readings fall outside of 35% to 55% you claim will be denied.

There is a big difference between a plastic vapor barrier, and insulation.   Read up on the two.  If your shed it totally above ground, you should not need a vapor barrier.  However, the outside structure plywood should have Tyvek or similar plastic water protection wrap on it, underneath the siding, which keeps water droplets from coming into the walls, but allows moisture to wick out of the walls.

Insulation is always nice to have. It makes the room more comfortable inside whether it is summer or winter.  It also helps to keep the hollow spaces between the studs from becoming wasp hives and spider nests. 

Whether you decide to insulate or not, you can't totally seal the room up like it is a plastic bag.   Big damage will occur.   So, no matter  what,  you should have a small vent near the floor on one side, and a small vent near the ceiling, on the other wall.

Dehumidifiers work extremely well and can totally eliminate all of your worries about excess moisture, mold, rust and rot.   The cheaper the unit you buy, the quicker it will burn out.   Buy one in the $500 range, set it to 50%, and forget about it.  Be sure to have a drain line running out the back and into the yard, flowing away from the foundation.   I

I've had my layout set up in the basement for almost two years.  I live in an extremely humid area.  I keep my dehumidifier set on 50%, and I have absolutely zero rust on any of my track, rolling stock, or soldering spots.

Mannyrock

I'll present an opposing view.  You should always install a vapor barrier, it's just good construction practice, and it costs next to nothing if you do it during the insulating phase.  I'd certainly NEVER enclose an outside wall without insulation and a vapor barrier.

Do I Need a Vapor Barrier?

For my last train room which was a 859 sq ft converted garage and several additions that we built,  the insulation of choice was professionally applied closed cell spray foam.

We also used it in an old stone wall basement plagued with insects, air leaks and moisture.  This provided a bug free, quiet, clean and  arid environment.

No vapor barriers needed with spray foam.  Our projects used 3 1/2" and 5 1/2"  foam thickness depending on situation.   Spray foam costs more however it provides a perfect seal and there is no batt insulation labor factor.

Information given to us says that spray foam installs at 7.25 R and then settles down to about 6.9 R per inch of thickness.

As GRJ says conventional insulation absolutely needs a interior vapor barrier.

For the somewhat raw environment of the free standing non temp conditioned building, you may wish to approach this project with a mind set of an outdoor garden railroad.

GG stainless steel rail in plastic ties would be the first consideration for me.

Battery R/C operation would be my second consideration.

I have some old unusable GG track removed from a moist basement layout and it has rust bloches through out.

As an experiment, I increased my dehumidifiers from 40% to 50% to see what the effect was.  After one day, I could certainly tell the difference, and I started getting that damp basement smell as well.  Back to 40%, IMO 50% is too moist for the basement settings.

I typically run between 50-60%. I run 2 units and 2 dehumidifiers. Typically empty them each 1-2 times per day to maintain below 60%. Room is insulated with RF13.

Both of my units have drains so I don't have to keep emptying them.

They also make dehumidifiers now with a built in water pump, if you have no drain in the floor. Their more expensive but you'll be happy you no longer have to empty the bucket.

Dave, while they do exist, I've had three of them, all of them had the pump crap out before the one year warranty ran out.  The good thing was I got a new dehumidifier and could use the old one with the drain, but don't count on the pump lasting very long!  I just moved the dehumidifier next to the sump, and the other one is next to a floor drain, problem solved.

@Dave Zucal posted:

They also make dehumidifiers now with a built in water pump, if you have no drain in the floor. Their more expensive but you'll be happy you no longer have to empty the bucket.

I had 3 Soleus. First two had the pump quit a little over a year. When the pump quit the dehumidifier shut them selves down and would not even drain into their buckets. Last one leaked it's refrigerant out and was replaced with a Midea. I built a stand for it and drain it out the A/C drain on the furnace. Gravity drain is the best in my HMO.

Yep, even the dehumidifier makers can't thwart gravity!

Dehumidifiers in my world are not durable.   Because of their inherent short life cycle I purchase them at Lowe's and purchase the extended replacement warranty.   Replacement has been easy.  Lowe's has replaced two major appliances and three dehumidifiers for me.

@Tom Tee posted:

Dehumidifiers in my world are not durable.   Because of their inherent short life cycle I purchase them at Lowe's and purchase the extended replacement warranty.   Replacement has been easy.  Lowe's has replaced two major appliances and three dehumidifiers for me.

I expect a couple of years from a dehumidifier, that's all you get from them.  I had one unit that lasted about 4 years, a Frigidaire.  I was actually pretty surprised I got that kind of life out of it.  I like the idea of using the Lowes extended warranty, I think that's how my next one will be done.

I run the HOME Labs dehumidifiers around 45% year-round and the basement stays pretty dry.  The previous brand we had was GE and we were lucky to get 2 years out of them.  The HOME Labs are going on 3 years without a problem.  Here in Connecticut, you should have a vapor barrier in the basement.

Marty

I picked up a GE dehumidifier last year for my walk-out basement train room and keep it at a constant 45% which seems right for my situation near the Massachusetts coast. Anything higher and it can feel "clammy" and anything lower and it just runs constantly.

It doesn't have a pump and I have no floor or other drains to run it into, so I empty it about once a day. One unforeseen benefit is that with the extreme drought in the northeast, many towns have instituted restrictions or outright bans (like my town) on outside water use, so I take the one gallon dehumidifier drain bucket outside and use it to water a small Japanese maple tree which is especially water/drought sensitive.

@Tom Tee

You stated that closed cell spray foam doesn’t need a vapor barrier.

My understanding is that extruded polystyrene foam insulation also is a closed cell foam.  

So is a vapor barrier needed with extruded polystyrene foam insulation ?  

Thanks in advance for your input.

Great information & thank you all for sharing your experiences !!!

CB&Q Bill

The following regards foam panels in a studded wall.

Depends on how air tight the panels are installed.

When I install foam panels I caulk them into place both sides top,  and bottom.

Usually use a 2" and 1 1/2" sandwich in a 3 1/2" bay.  Both of the panel levels get caulked.

I prefer not to use a vapor barrier when using the panels between  studs.  The poly sheets preempt using adhesive on the rock / stud interface.

Thank you to everyone for their input. I apologize for the lack of activity the past couple of days. A member of my family had a procedure done and has been in the hospital. I have been with them and haven't had the time to reply.

@Dennis-LaRock posted:

Looks to me like Tulsa is one of the better locations as it's fairly dry (annual precipitation 16.61").  Temperature swings seem relatively moderate as well.

Is there an interior wall and ceiling covering in the shop... i.e., can you 'see' the wall studs/roof rafters (no interior wall/ceiling covering) or are the studs/rafters covered with Sheetrock/paneling or some sort of sheet plastic?   You may want someone to take a look at it for you to determine how 'tight' the shop is.  If the walls/ceiling is covered... it probably does not need to be insulated because Tulsa is pretty darned dry with a very low average annual humidity.   All that said... I would have a dehumidifier installed.

Here is a dehumidifier example... key points ...50% larger than the room sq. footage, Drain Hose Outlet, Auto on/off.

hOmeLabs 22-Pint Dehumidifier $159.99

9.9 Rating

• Coverage Area: 1,500 sq ft
• Daily Moisture Removal: 22 pints
• Tank Capacity: 1 gallon
• Drain Hose Outlet: Yes
• Functions: Auto shut-off, restart, & defrost

There is no interior wall or ceiling,  just a sheet of plastic I'm assuming. Here is a recent photo I took, for reference.

Caleb,

I hope all went well with the procedure and they are recovering comfortably. 

The construction looks relatively new and in pretty good shape!  I would pick up a simple inexpensive thermometer/humidity combo... I prefer analog ...though others will beg to differ.  Monitor it for a week or two and it will give you some guidance on what dehumidifier to choose.   There are many mid-range (150-300) that are very well built and will get the job done.

Nice looking trains there buddy!

Gunrunner,

I totally agree with you that any heated or cooled enclosed space should have a vapor barrier for all exterior walls.

But, my understanding is that this is an outdoor shed, totally above ground, with no heating or cooling, in a low humidity region.

Good ventilation is all that is needed, so long as the outer covering is some type of siding, and not painted T1-11 plywood.

Just my opinion, based on 45 years of building outdoor buildings, stables and barns.

And, if people would use exterior grade 3/4 plywood for the wall sheathing, underneath the Tyvek and siding, instead of cheap OSB, this would never be an issue at all. :-O

Mannyrock