Moisture proofing walls and venting ideas. what would you do?

[Pedal Dangit]

I am currently planning my 150 gallon build in a small office that shares the display wall with the garage. I have had thoughts about trying to seal off the entire sump, tank, and hood against the wall and running a small vent into the garage to prevent heat and humidity in the small room. My thoughts were either painting the wall with mold resistant bathroom paint or using plastic wall board. Then, cutting out and building a vent through the wall (sealed and painted) or a large piece of PVC pipe with a fan. I understand this will only transfer the moisture into the garage, but our garage has a large vent to outside which I could also use a fan in summer months if it is a problem. It also helps that I am in southern CA and we only have a few months out of the year that are difficult.

Just curious if anyone has ideas or has done anything similar. I see a lot photos of giant in wall tanks and fish rooms and wonder how they handle humidity and moisture?

random image found on google

 

[SteveMM62Reef]

Do it right to begin with, either pull the old Sheetrock out, and replace it with Mold resistant Sheetrock or use a Foam type backer board. The backer board will have to be either Stuccoed, or Tiled. $$$ BTW You can get away with just doing the bottom Four Feet in the Mold Moisture resistant Sheetrock.

 

[Pedal Dangit]

Do it right to begin with, either pull the old Sheetrock out, and replace it with Mold resistant Sheetrock or use a Foam type backer board. The backer board will have to be either Stuccoed, or Tiled. $$$ BTW You can get away with just doing the bottom Four Feet in the Mold Moisture resistant Sheetrock.

great advice. I plan on pulling the wall apart anyhow to make access panel for the plumbing lines. So will replace that back wall with mold resistant sheetrock. now you have me thinking of doing a few feet up the wall with tile (we are tiling the floors anyhow) maybe to the height of stand level. it is a small wall between closet and angled window wall

 

[SteveMM62Reef]

Also I would Repaint your Stand. I made the mistake of putting an “Over-finish,“ on my 90 gallon stand. After a lot of research on my 65 gallon stand, I Shellac the bottom, the part that faces the floor, with 50/50 Shellac and Alcohol, then 75/25, followed by 100% Shellac. The inside, I used White Boat Topside Paint. Outside was Matt Black, so I used Krylon Matt. If your stand has a clear finish, the best stuff is Sikkens Primer followed by the Sikkens top coat. You can get it shipped to your local Walmart. It is close to impervious to the lights and salt.

 

[fishyguy7]

My fish room is all cement board and painted the bottom 12” with a waterproof shower membrane. All sealed to the concrete slab and the concrete is sealed with epoxy. For a vent I have a in-line fan from https://www.acinfinity.com/duct-fan-systems/. Set to come on at 80 degrees or at 40% humidity

 

[AlexG]

The strategy I use for humidity control is: Minimize, Contain, Mitigate.

Minimize: Use lids on all tanks cut to accommodate for plumbing and cords

Contain: Moisture proof the walls and ceiling with FRP boards, Plastic sheeting, gorilla tape on all seems. Create a negative pressure in the room that will contain the humidity using exhaust fans or a dehumidifier

Mitigate: Dehumidifier, Air exchanger, exhaust fan (Method will depend on climate and geographic location) Also caution must be taken with ventilation methods to exhaust air in high volumes as too much exhaust without a sufficient means to bring in fresh air can cause chimneys to reverse airflow which can put anyone in the home at risk of carbon monoxide poisoning.

In my new fish room that is under construction has FRP boards on the walls and plastic on the ceiling with all seams taped. I also have pond liner sealed to the floor in areas that have FRP board which covers the back side of finished basement walls. I will be installing a ducted whole house dehumidifier that will be ducted to the canopies of the larger tanks in the fish room as well as the display to ensure the moisture generated over these tanks in the canopy sections will be mitigated before the air returns to the rest of the house. It can be a costly install to have moisture mitigation steps in place but its worth every penny to prevent the moisture from damaging your home.

 

[User]

The strategy I use for humidity control is: Minimize, Contain, Mitigate.

Minimize: Use lids on all tanks cut to accommodate for plumbing and cords

Contain: Moisture proof the walls and ceiling with FRP boards, Plastic sheeting, gorilla tape on all seems. Create a negative pressure in the room that will contain the humidity using exhaust fans or a dehumidifier

Mitigate: Dehumidifier, Air exchanger, exhaust fan (Method will depend on climate and geographic location) Also caution must be taken with ventilation methods to exhaust air in high volumes as too much exhaust without a sufficient means to bring in fresh air can cause chimneys to reverse airflow which can put anyone in the home at risk of carbon monoxide poisoning.

In my new fish room that is under construction has FRP boards on the walls and plastic on the ceiling with all seams taped. I also have pond liner sealed to the floor in areas that have FRP board which covers the back side of finished basement walls. I will be installing a ducted whole house dehumidifier that will be ducted to the canopies of the larger tanks in the fish room as well as the display to ensure the moisture generated over these tanks in the canopy sections will be mitigated before the air returns to the rest of the house. It can be a costly install to have moisture mitigation steps in place but its worth every penny to prevent the moisture from damaging your home.

That’s legit.

I moved from a small 10x8 fishroom that was framed out in my basement. I used 5/8 ply for the walls, painted with 2 coats of killz, then a coat of latex bathroom paint. Caulked and sealed all seams, epoxy floor. Humidistat to vent humidity outside. Worked very well

I’m in the process of moving my fishroom, into a 13x16, with concrete walls on two sides. Rest is currently unframed. I have to get my system running before the room will even have power, and I planned to do a lot of the things mentioned here.

However- I kinda planned on not finishing the concrete walls, but I keep flip flopping. I keep thinking maybe I should at the least put drylok paint on the walls, so that condensation on the cold walls doesn’t damage the concrete - but I intend to have ventilation and dehumidification to reduce the condensation potential as much as I can.

Any thoughts on the drylok?

the rest of the room will be finished with moisture-resistant drywall, and some plywood panels recovered from breaking down my old fishroom, very much like like you describe.

 

[User]

New space

old fishroom mid breakdown

 

[CMMorgan]

I would not run a vent into the garage. In most municipalities, it is actually a code violation. On one front, you are moving moisture to the garage, which will lead to rust and mildew / mold. On the other, you are providing a vehicle (pun intended) for carbon monoxide to enter your home. Please don't do this.
You could consider installing a bath type fan. Panasonic make models with very low sones that have humidity sensors. You can set the humidity level and it will turn on and off to vent the space based on the humidity. You can duct it to the outside through the attic through a gable if you do not want to penetrate the roof.

 

[Bridgerdean]

Nice advice CMMorgan. Agreed with a humidity sensing bath fan.

 

[Bridgerdean]

This may be overkill. but I tore out my sheetrock and put in pressure treated plywood. Then skim-coated with mud, and primed with KILZ mold resistant paint.

 

[User]

This may be overkill. but I tore out my sheetrock and put in pressure treated plywood. Then skim-coated with mud, and primed with KILZ mold resistant paint.

I did plywood and killz x2, then bathroom latex paint. Sealed all seams with silicone.

I pulled a panel the other day since I’m breaking it all down, and the wall behind it had zero indication it had been covered.

 

[Hydrored]

Check out Aprilaire, they have a bunch of options for air exchange along with humidity control. I ended up installing a whole home one almost a year ago

 

[AlexG]

That’s legit.

I moved from a small 10x8 fishroom that was framed out in my basement. I used 5/8 ply for the walls, painted with 2 coats of killz, then a coat of latex bathroom paint. Caulked and sealed all seams, epoxy floor. Humidistat to vent humidity outside. Worked very well

I’m in the process of moving my fishroom, into a 13x16, with concrete walls on two sides. Rest is currently unframed. I have to get my system running before the room will even have power, and I planned to do a lot of the things mentioned here.

However- I kinda planned on not finishing the concrete walls, but I keep flip flopping. I keep thinking maybe I should at the least put drylok paint on the walls, so that condensation on the cold walls doesn’t damage the concrete - but I intend to have ventilation and dehumidification to reduce the condensation potential as much as I can.

Any thoughts on the drylok?

the rest of the room will be finished with moisture-resistant drywall, and some plywood panels recovered from breaking down my old fishroom, very much like like you describe.

I did research using drylock on my basement walls at my first house with a monster aquarium system and I decided against using it as the concrete walls can effectively transfer moisture through them which can be helpful to absorb some moisture. The concern with Drylock was that while it will moisture proof the wall it would not be able to hold back a high ground water level due to the pressure it would create from outside which could damage the basement walls. With condensation drylock would not prevent that as it comes down to having insulation to create a barrier between the cold wall and the inside air that would condense against the wall. I had to deal with condensation at the top of my basement walls in the winter in the fish room when it got below 20F outside. I deployed a fan on the impacted parts of the walls with condensation and it eliminated the issue by constantly evaporating any condensation that formed. In my new basement there is insulation on the concrete from the frost line up so that issue should be mitigated.

 

[Gp!]

If you're tearing out the interior and plumbing through walls you can also go for an in wall dehumidifier like https://www.innovativedehumidifiers.com/

 

[Pedal Dangit]

Thanks everyone for all these excellent ideas. I think how to deal with humidity and moisture is something that almost all new tank owners don't even think about until they have had a large tank set up against a wall for a while. My mom tried to have a saltwater tank in Texas and I remember after a few years her saying that the wall had mold and the AC system had rust. Here in Temecula, CA I'm lucky to live in a warm & dry climate for most of the year. My current 40G breeder set up is not a problem in the open kitchen area. I leave the all doors open most of the time. It's those few miserable months in Summer I'm trying to plan for with the large tank in a small room. I was surprised I didn't find a dedicated thread when searching around on reef2reef. lets keep the ideas coming!

 

[User]

I did research using drylock on my basement walls at my first house with a monster aquarium system and I decided against using it as the concrete walls can effectively transfer moisture through them which can be helpful to absorb some moisture. The concern with Drylock was that while it will moisture proof the wall it would not be able to hold back a high ground water level due to the pressure it would create from outside which could damage the basement walls. With condensation drylock would not prevent that as it comes down to having insulation to create a barrier between the cold wall and the inside air that would condense against the wall. I had to deal with condensation at the top of my basement walls in the winter in the fish room when it got below 20F outside. I deployed a fan on the impacted parts of the walls with condensation and it eliminated the issue by constantly evaporating any condensation that formed. In my new basement there is insulation on the concrete from the frost line up so that issue should be mitigated.

my understanding is that the drylok has been formulated to resist 22 feet equivalent of head pressure before failure, which is many times higher than the pressure required to damage the walls.


I do remember some People had misgivings from my first build where people said I shouldn’t have dryloked my conderblock wall before I put a frame wall in front of it (I don’t know I would be doing that when I painted it) but the concern was moisture removal and condensation.


Of course, I understood that just painting won’t stop condensation, since it’s the interface between a cold wall surface and the warm moist air that does it- I’ll be venting appropriately to bring humidity and temp down to human levels. The 3 weeks in my old fishroom before I finally hooked up the inline fan were miserable in there

 

[Pedal Dangit]

My fish room is all cement board and painted the bottom 12” with a waterproof shower membrane. All sealed to the concrete slab and the concrete is sealed with epoxy. For a vent I have a in-line fan from https://www.acinfinity.com/duct-fan-systems/. Set to come on at 80 degrees or at 40% humidity

that acinfinity fan system looks like a great solution. have any pictures of how you did the duct work for it?

 

[AlexG]

my understanding is that the drylok has been formulated to resist 22 feet equivalent of head pressure before failure, which is many times higher than the pressure required to damage the walls.


I do remember some People had misgivings from my first build where people said I shouldn’t have dryloked my conderblock wall before I put a frame wall in front of it (I don’t know I would be doing that when I painted it) but the concern was moisture removal and condensation.


Of course, I understood that just painting won’t stop condensation, since it’s the interface between a cold wall surface and the warm moist air that does it- I’ll be venting appropriately to bring humidity and temp down to human levels. The 3 weeks in my old fishroom before I finally hooked up the inline fan were miserable in there

Thats a good piece of information on Drylok pressure resistance. I can see a concern with putting a frame wall in front of a drylok wall with condensation but a layer of insulation would mitigate that issue. I am just hoping my new dehumidifier shows up soon as I am going to need it once my next tank in the system goes online after a fill test.

 

[User]

Thats a good piece of information on Drylok pressure resistance. I can see a concern with putting a frame wall in front of a drylok wall with condensation but a layer of insulation would mitigate that issue. I am just hoping my new dehumidifier shows up soon as I am going to need it once my next tank in the system goes online after a fill test.

Yeah- and the extreme can withstand 33 feet of standing water.

in my last fishroom, I had the drylok painted wall, and then a 2x4 stud wall covered with psi eyed plywood. Fiberglass insulation inside- which I slit the paper on and placed it ‘backwards’ since the heat and moisture is in the room. having a vapor barrier before the insulation would have led to moisture build up on the walls. This was recommended to me by insulation experts and was because of the drylok painted wall. Also 3.5 years ago so I’m probably butchering the info

I pulled one of those panels last week and everything was bone dry. To the point that I should be able to reuse the insulation in my new place.

I’ve decided I will drylok, or at least paint, the foundation walls, because exposed concrete tends to ‘dust off’ and I don’t want the effervescence appearing in wet areas if I have saltwater splash back from the sump.

I’m going with a light blue tint since the put white is a little sterile