Fish Room Drywall... Normal or moisture and mold resistant?

As for tying exhaust in, I hope you are not talking about into the flu pipe of furnace or water tank. That does not sound like a good idea. Power vented or not, you will still be creating a back pressure on the system that will cause them to not function properly. Best case, premature failure of the appliance, worst case, dumping a ton of CO into your house.....best case of that, major algae problems....worst, you and your family never wake up!!
Definitely take that directly outside! Even if you use the 4" flexible dryer vent piping
 
I am about to build an 14 x 14 fish room. I am going with green board, clear plastic behind it and an exhaust fan with a humidity controller.... Living on the water I can tell you that the first time you build something without thinking about the long term effect of water you will be fine for 5-6 years with no problems. However, day after day with increased moisture will come back and haunt you. Your fish room will carry a much higher humidity number then a bathroom...
 
Jeff-

I've got some concerns for your build long run; you voiced two things that scare me greatly....

Tying into a vent line is not only not good; as voiced above it can be deadly for you and your family. I'd strongly recommend you cut a hole and direct vent your fishtank room (As mine currently is, through a 4" dryer-vent style hole.)

Next, although your humidity in the room will be lower than say, after you took a long steamy shower with the room all closed up, it'll be continuous. Plus, the salt in the air is REALLY corrosive. I ran a utility room behind my tank with a fresh air return line in it for about 5 years; ask me what that vent looked like (And that was with a dehumidifier.) Using Green or Purple boards (Sheetrock and USG brands, respectively, for moisture resistance) should be, without question, used. Ditto for fiberglass tape for seaming.

Is your furnace room also the room where your breaker box is located? If so, I'd keep it out of that room. Corrosive elements plus your electric supply can also be deadly (Think heat/fire from resistance.) Keeping it next to a furnace will degrade and shorten the life of the PC Boards internally (They're usually not potted/sealed; most aren't), the fan, and the duct work.

Lastly, adding plastic to exterior facing walls is actually code here (8 mil; plus taping where there are staple holes/seams for vapor barrier.) Adding it to internal walls can have odd effects for moisture and heat dissipation, as well as airflow between rooms.

Keep in mind, building codes vary from location to location, but should be viewed as *minimum* safe levels to build to, not as something you should strive for. Contractors in housing developments build homes for other people, not themselves, and will build as cheaply as they can legally get away with, including saving $2 a sheet on drywall, as long as it fails after the warranty period.

I'd seriously suggest consulting a contractor; even for ideas. Period. If you're not familiar with the effects of airborne corrosives in your house, and/or basic local code or building materials. Some will offer a visit for "consulting" on your home projects. It may save your life, and it'll definitely save your wallet in the long run.

If you ask how I know, I flip, and rebuild higher-end real estate (I'm on house 12; never had issues passing a code inspection post and during rebuild, either.)

You *can* get away without consulting a pro, but I'm a firm believer in spending a little more upfront and making sure it doesn't fail in the long run (Or try to kill you.)
 
I insulated and used 4 mil plastic to cover my fish room. I didn't drywall the room because I wanted easy access to all wiring and plumbing. I also installed a cheap bathroom fan in the room which is vented with a 4" pipe to the outside. If you use plastic over insulation make sure to use the paperless insulation. The paper on insulation is considered a vapor barrier and if you put plastic over paper that will be two vapor barriers together which means if water gets in between them you will have mold and it would defeat the purpose of using plastic.
 
Jeff-

I've got some concerns for your build long run; you voiced two things that scare me greatly....

Tying into a vent line is not only not good; as voiced above it can be deadly for you and your family. I'd strongly recommend you cut a hole and direct vent your fishtank room (As mine currently is, through a 4" dryer-vent style hole.)

Next, although your humidity in the room will be lower than say, after you took a long steamy shower with the room all closed up, it'll be continuous. Plus, the salt in the air is REALLY corrosive. I ran a utility room behind my tank with a fresh air return line in it for about 5 years; ask me what that vent looked like (And that was with a dehumidifier.) Using Green or Purple boards (Sheetrock and USG brands, respectively, for moisture resistance) should be, without question, used. Ditto for fiberglass tape for seaming.

Is your furnace room also the room where your breaker box is located? If so, I'd keep it out of that room. Corrosive elements plus your electric supply can also be deadly (Think heat/fire from resistance.) Keeping it next to a furnace will degrade and shorten the life of the PC Boards internally (They're usually not potted/sealed; most aren't), the fan, and the duct work.

Lastly, adding plastic to exterior facing walls is actually code here (8 mil; plus taping where there are staple holes/seams for vapor barrier.) Adding it to internal walls can have odd effects for moisture and heat dissipation, as well as airflow between rooms.

Keep in mind, building codes vary from location to location, but should be viewed as *minimum* safe levels to build to, not as something you should strive for. Contractors in housing developments build homes for other people, not themselves, and will build as cheaply as they can legally get away with, including saving $2 a sheet on drywall, as long as it fails after the warranty period.

I'd seriously suggest consulting a contractor; even for ideas. Period. If you're not familiar with the effects of airborne corrosives in your house, and/or basic local code or building materials. Some will offer a visit for "consulting" on your home projects. It may save your life, and it'll definitely save your wallet in the long run.

If you ask how I know, I flip, and rebuild higher-end real estate (I'm on house 12; never had issues passing a code inspection post and during rebuild, either.)

You *can* get away without consulting a pro, but I'm a firm believer in spending a little more upfront and making sure it doesn't fail in the long run (Or try to kill you.)

I'm a Jman Electrician. 100% commercial. If the humidity from steam mechanical rooms is fine for normal drywall, I am sure it'll be fine for my fish room. (as per what the drywaller said)

I'm going to run a separate line for the exhaust. PVC, as I am told it'll be the only line I would have to worry about rusting. The HVAC guy at work is bringing me an inline fan for a pvc pipe. Apparently this is what they do at salt water pools, run pvc exhausts, normal everything else.

Electrical is not a worry, its not in that room right now, but will be moved in there at some point. Using a commercial weather tight square d panel I have left over for a job. But wouldn't hesitate to use a normal panel.
I've reno'ed two salt water fish stores, and while some of the receptacle boxes were looking rough after 10 years, there was no rust, and the actual receptacles all looked good (outside of the poor workmanship). The fish stores were green board though.
Now that I think about it, I am more worried about my concrete floor then drywall, both fish stores had bare concrete in the back rooms that was just destroyed. Epoxy here I come... I hope it doesn't suck to put down.

I think I'll insulate the walls too, with some roxul s&s.


Contractors build to be cost effective. It's not like they frame the house with j grade and use MgO board through out. And then run #12 AWG throughout the house, etc etc. Because at the end of the day, the house will cost 3x as much and have no added functionality. Well maybe the MgO board.
 
I'm going to run a separate line for the exhaust. PVC, as I am told it'll be the only line I would have to worry about rusting. The HVAC guy at work is bringing me an inline fan for a pvc pipe. Apparently this is what they do at salt water pools, run pvc exhausts, normal everything else.
Good call on this, you do not want to tie a vented gas line into an air vent line. Besides much like those high efficiency heaters (90+) too much moisture in your pipes will rust them out, more likely than not in places where you can't see them (like inside of the bulkhead/wall where the pipes exit).

Just make sure you hook your exhaust fan to a humidistat you don't want your furnace prematurely rusting out, and it will if it gets too humid.
 
Does anybody know for a fact that salt from our tanks does get airborne? I have seen this mentioned quite a few times, including this thread. I was always under the impression when water evaporates and re-condensates you end up with a very pure form of water. But that would also be under ideal conditions. I do know from experience you cam get some spray from crashing water.
 
Salt doesn't get airborne from evaporation, but it can be extremely surprising how far a tiny droplet of saltwater can travel as "spray"

That said, the humidity alone in a fish room would be enough to corrode most metals in quick fashion.
 
I was under the impression that salt dust gets in the air, and then the moisture gets to that dust. But I dunno.

I'll hook the fan to a humistat, and probably have it come on via a timer too, like run for 30 minutes right after lights go out or something.
 
I have some issues with the furnace room and the fish room also. First, I am a bit confused as to why a tank would go there in the first place, but to each his own! California Paints has a lot of interior primer selections and they also have NO-VOC paint, which I think would be good in this situation. They are definitely worth a check out. Good luck!
 
I like the plywood idea, very nice. When i redid the wall where my tank is on the basement, i used cement board (durock) covered with sheets of white frp paneling from home depot, all put up with adhesive, sealed etc, even he baseboard molding I used PVC trim. Never thought about using ply...would
Have been the best way to go IMO.
 
I used all plywood with varnish in my fish room and it was still a but humid in there, so then I stuckoed the walls and it was better.. finally added two large exhaust fans and voila ....
 
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