HUMIDITY! Oh yes...

[MikeOwnby]

All you new guys: Make your room conditions constant. Temperature is easy, but you have to do the humidity thing too.

I thought I'd pop this in here just because I've seen a lot of "new layout" threads here on this forum, and a post from another place was brought to my attention. This person, after more than a year and a half of his layout functioning perfectly, suddenly came home to <gasp> buckled tracks! And yeah, I'm not trying to make light of it. I've had it happen, and it is freaking traumatic. The thing that got my attention was that what happened to him was just about exactly what happened to me, and for a LONG string of responses people just completely ignored the most obvious gremlin. Everything was about temperature and metal expansion and the rails. No.

Now look, after 18 months your layout has already undergone all sorts of temperature changes if they exist. And this guy says he maintained a fairly average 70-ish temp, give or take. But here's the thing: temperature changes tend to be pretty darn immediate, and metal will let you know right away if you've pissed it off. Not one of the first dozen troubleshooters brought up anything about the wood. What take time is wood. It'll bleed off and suck back in any moisture you care to give it, and it'll grow or shrink right along with it, but it does do it slowly and it's like a seismic fault that's storing energy. It'll overcome whatever mechanical or structural devices you have in place after a year (or a year and a half) of starving wood of moisture, and you'll find out that it got tired of being thirsty and decided to let you know about it. My own epiphany on this was not a happy time, but I did luckily manage to fix the damage. How? I put a humidifier in the room and let it run for a month. Yes, a MONTH. I'd cut out some flex track to relieve the pressure that was seriously pretzel-ing a couple of my turnouts, but it took that long before my layout finally expanded back to its original size enough for me to put even slightly filed down pieces back into the same places.

The lesson, boys and girls: Temperature is NOT all there is to a happy layout room. While metal rails will expand and contract rather quickly, the underlying benchwork will actually react much more dramatically in the end even if it takes longer to do so. Leave your business-card gaps and non-soldered joiners every so often if you want to (it's good advice for larger layouts no doubt), but for the love of pete also go out there and buy whatever humidifiers and dehumidifiers will keep your benchwork from overtopping those precautions. I have both ever since "THE INCIDENT". I live in a place that gets very humid in the summer and very cold and dry in the winter. It cost me probably close to $400 if I remember right for both units, but how much is your benchwork, your trackwork, worth? I've kept my temperature in the 75-deg range and my humidity in the 50% range to accommodate both summer and winter, with just switching out on which piece of equipment is doing the job. Not only have I not had a repeat of "THE INCIDENT", I've also never had even the slightest variation in connections that I'd previously wondered about before I got smacked in the face.

It's a pretty good preventative investment that not a lot of folks seem to be talking about, if the posts on that other place were any indication. Make the investment before the damage occurs, and you'll be much happier. Considering what this hobby costs overall, it seems like even a few hundred dollars is a pretty wise investment to keep it running right.

 

[santafewillie]

Mike - You hit the nail squarely on the head. Humidity is the greater problem. Lucky for me, my humidity stays pretty constant around here unless it's raining outside, which is mostly rare (except 2015). The humidity doesn't stay high for long enough to have too much effect. I don't solder most track, and when I lay track in cooler temperatures, I too leave a business card thick gap between pieces of flex, with some exceptions on curves. I do have lots and lots of feeders (no not every three feet, but close) to ensure ample power supply over the entire layout. But don't completely rule out temperature. My old train room was a lean-to structure (sheet metal roof no less) on the back side of my barn with no climate control, and the temps ranged from 0-114 degrees. You should see unballasted track at 114!

Willie

 

[Rico]

Yup I've seen a lot of people get into this hobby only to have their efforts twisted like a drill bit.
Although I've never had that problem with my layout benchwork (I use plywood and no two by any things) I have had some temperature related issues with scenery or track work.
To combat this we tore out all the fibreglass insulation in our walkout basement and replaced it with spray foam insulation.
What a great difference that made!

Only one problem I never thought of, the concrete footing is exposed to the outside air on the rear of the house and cold transmits under my nice toasty warm wall and condenses the moist inside air along the bottom. Keeping stored items a couple inches away from the wall to allow airflow helps.
We also bought a dehumidifier for the sacred chamber of the silver rails and for now all is well.

 

[Iron Horseman]

It is sort of funny but in Colorado the trains need to have a humidifier, while at the Kansas property there have to be dehumidifiers. To bad I just can't have a vent between the two.

 

[MikeOwnby]

Mike - You hit the nail squarely on the head. Humidity is the greater problem. Lucky for me, my humidity stays pretty constant around here unless it's raining outside, which is mostly rare (except 2015). The humidity doesn't stay high for long enough to have too much effect. I don't solder most track, and when I lay track in cooler temperatures, I too leave a business card thick gap between pieces of flex, with some exceptions on curves. I do have lots and lots of feeders (no not every three feet, but close) to ensure ample power supply over the entire layout. But don't completely rule out temperature. My old train room was a lean-to structure (sheet metal roof no less) on the back side of my barn with no climate control, and the temps ranged from 0-114 degrees. You should see unballasted track at 114!

Willie

Absolutely not ruling out temperature as to it having an effect if it's allowed to fluctuate. I possibly didn't make it clear, so thanks for re-iterating that. Temperature definitely needs to be controlled or accounted for, but it IS also a fairly immediate reaction. It doesn't take 18 months for metal to shrink or expand and show a problem. You know right away when metal isn't happy with you for making it sweat or freeze, but I've discovered on many occasions that a lot of people don't know that wood doesn't care about temperature, only humidity. I'm posting a picture of my layout's framework so you can see what I'm talking about here, but seriously...I would have thought it was shrink-proof if you'd asked me 18 months before my turnouts buckled. That jigsaw puzzle construction is something I did to keep supporting framework from interfering with under-table turnout motors, but the unintentional side effect is that there are NO pieces of the layout (other than the outermost fascia) which actually run the length of the layout, and that makes for some pretty serious flexibility. Any shrinkage in a particular piece due just to aging is absorbed somewhat by others. I used OSB, which is even more shrink and expansion resistant than plywood, for the decking of the layout. Honestly, if my layout was HO, then *maybe* that would have been enough to withstand the variances in humidity. THE INCIDENT (yes, it deserves to have a name and be in all-caps) was a result of maybe at most 1/4" shrink over a 12 foot span, but it manifested, of course, at whatever point that pressure could finally be released. It took 18 months for the wood to work against the screws that were holding everything together and finally find a little wriggle room for it to relax and shrink itself. And really, that's the thing right there. There's not much you can do with glue or screws that will hold up to months and years of constant, unyielding pressure. If nothing else, the wood itself will finally give at some point. I'm sure the OSB decking actually kept it from shrinking for a long time, but finally succumbed to the pressure. The only fix to keep wood from getting fat and skinny as the seasons change is to just make sure you have a mechanical contrivance that prevents those seasonal changes within your hallowed walls.

And really, the whole point of this post was just to remind people to take that into consideration. Educate people that moisture matters when you've got wood in the room, and possibly save them from having their own "awww F@#*!!!!!" moment.

 

[Boris]

Great topic. I don't have a temperature problem in my basement train room, but I do have a major humidity problem. (It's Jersey, after all). My solution, was, (is), to run a humidifier with the heat (gas, hot air), so it's not too dry in the winter, and to run a dehumidifier all year. It normally doesn't run when the heat is running, but kicks on during the mild days when the heat doesn't run. In the summer the air conditioning helps control the humidity along with the dehumidifier.

Another thing is that my wooden legs do not make contact with the concrete basement floor. This prevents wicking of moisture from the floor to the wood. So far, over 30 years, no buckled track in summer or pull aparts in winter.

 

[MikeOwnby]

Great topic. I don't have a temperature problem in my basement train room, but I do have a major humidity problem. (It's Jersey, after all). My solution, was, (is), to run a humidifier with the heat (gas, hot air), so it's not too dry in the winter, and to run a dehumidifier all year. It normally doesn't run when the heat is running, but kicks on during the mild days when the heat doesn't run. In the summer the air conditioning helps control the humidity along with the dehumidifier.

Another thing is that my wooden legs do not make contact with the concrete basement floor. This prevents wicking of moisture from the floor to the wood. So far, over 30 years, no buckled track in summer or pull aparts in winter.

Exactly what I'm doing, except that I never thought of isolating the legs. I think I'm gonna hunt down some plastic to remedy that. Thank you.

 

[tootnkumin]

If you're ever short of a bit of that humidity stuff Mike, I'll grab an envelope, go outside and wave it about to collect some and post it over. Or maybe a few container fulls.

 

[Sirfoldalot]

Great topic. I don't have a temperature problem in my basement train room, but I do have a major humidity problem. (It's Jersey, after all). My solution, was, (is), to run a humidifier with the heat (gas, hot air), so it's not too dry in the winter, and to run a dehumidifier all year. It normally doesn't run when the heat is running, but kicks on during the mild days when the heat doesn't run. In the summer the air conditioning helps control the humidity along with the dehumidifier.

Another thing is that my wooden legs do not make contact with the concrete basement floor. This prevents wicking of moisture from the floor to the wood. So far, over 30 years, no buckled track in summer or pull aparts in winter.

Been so used to living on the Western side of the divide for the last 30 years that I had forgotten about this. Same thing in KC. Had both units, just as Joe mentioned. My dehumidifier from April - September actually ran a constant stream of water.

 

[roofintrash]

Not sure if it's a camera trick or not,but is your framework treated 1xs?

 

[MikeOwnby]

Not sure if it's a camera trick or not,but is your framework treated 1xs?

No, they're not treated. Or at least they weren't supposed to be. I didn't notice any excess moisture that I usually get when cutting or driving screws into treated lumber, so I'm not sure why they have that green tint. If I did get bamboozled on that, it would help explain why it did end up shrinking and causing problems, but I did order non-treated lumber.

 

[roofintrash]

No, they're not treated. Or at least they weren't supposed to be. I didn't notice any excess moisture that I usually get when cutting or driving screws into treated lumber, so I'm not sure why they have that green tint.

When I saw the green tint I thought ,well there's the problem, as treated shrinks like crazy. Strange camera tricks lol

 

[MikeOwnby]

When I saw the green tint I thought ,well there's the problem, as treated shrinks like crazy. Strange camera tricks lol

It's really not camera tricks, the wood does have that green tint to it. Like I say, I never noticed the moisture that usually appears when you drive a screw into treated lumber, but that's about all I have to go on. It'd be my luck that they heard the "treated" part and didn't get the "non-". Not sure how to tell if it's treated or not other than the screw test I've already mentioned. In any case, the last couple years since I stabilized the humidity there's been no other problems.

 

[roofintrash]

If you've already had the shrinking problem it's probably stabilized. I wouldn't worry about it.
I built a privacy fence at my old bosses house and spaced the treated 1x slats with an 8 penny nail per his request. After 1 summer you could stick your finger between them. I hate treated lumber.

 

[Greg@mnrr]

One thing I like to add is that any lumber one uses for a basement layout should spend some time in the basement becoming acclimated to the humidity conditions of the basement area. The wood may dry or pick up moisture in the basement area that should happen before construction.

I constructed a room in the basement 36 years ago and used oak paneling over drywall. The lumber dealer suggested that I leave the paneling "age" for at least two weeks in the basement for it to acclimate to the conditions in the basement. I followed his advice and after all these years the panel seams and the paneling itself didn't buckle or move at all. The panel were laid edge up with spacers between the 20 or so panels.

I also run a dehumifier during spring, summer and fall. Another benefit of running a dehumidifier is the lower humidity will prevent rusting of metal parts, especially the axles on rolling stock and locomotives.

Thanks.

Greg

 

[MikeOwnby]

One thing I like to add is that any lumber one uses for a basement layout should spend some time in the basement becoming acclimated to the humidity conditions of the basement area. The wood may dry or pick up moisture in the basement area that should happen before construction.

I constructed a room in the basement 36 years ago and used oak paneling over drywall. The lumber dealer suggested that I leave the paneling "age" for at least two weeks in the basement for it to acclimate to the conditions in the basement. I followed his advice and after all these years the panel seams and the paneling itself didn't buckle or move at all. The panel were laid edge up with spacers between the 20 or so panels.

I also run a dehumifier during spring, summer and fall. Another benefit of running a dehumidifier is the lower humidity will prevent rusting of metal parts, especially the axles on rolling stock and locomotives.

Thanks.

Greg

That is absolutely wonderful advice, and I think it goes beyond the basement. If you're going to keep your humidity at a constant point, it's likely not going to be anywhere near what was happening at the lumber yard where the wood lived before you brought it home.

I also agree that lower humidity is generally better, though you definitely need to acclimate your wood if you're trying to keep it at a very low level. Where I live, the humidity in summer can easily hit 80% or more on any given day, and winter heat dries out the air to the point that 20% humidity is not at all uncommon left unchecked. I decided to keep the room at 50% all year round and split the difference. It's a compromise that allows both my humidifier and dehumidifier to do their jobs and 50% is also a very comfortable humidity to live in for the humans in the room. If you're in a place that stays drier in the summer months and you can get away with lower humidity, more power to you.