Defeating Moisture Issues in plywood room

I'm hoping someone can just post a link on here for me to check out, I did a bit of digging myself but wasn't fully satisfied with what I read.

My question is does anyone think or know I will have moisture (mainly mold) issues by building my own grow room instead of buying a tent. I'm going to build it out of 2x2 for the framing, with 4x8 moisture resistant plywood or at least the closest I can find to it and no press plywood at all. I already bought myself a 640cfm inline fan for my out take, and the room itself is going to be 280 cubic feet, yes the fan is overkill but I also bought a dial for its speed.

So with obvious adequate movement of air at my disposal, will that be enough to stop any mold build up? And I'm not referring to on the plants themselves, but actually the walls, floor, or ceiling of the room. I am going to line it with panda paper for light reflection, but a friend of mine did have a similar set up and found a little mold after one harvest. It was a smaller box and no, he did not have proper air flow, his relative humidity average from what he remembers was about the mid to high 60's at the most through the grow.

Should I just paint the interior of the plywood with moisture resistant paint? Then throw the panda paper over it for reflection? Input or a link would really put me at ease before I dive into either building my own room, or buckling and just buying a tent (rather not have to, seen millions of them and yes they work and are very cool, but I still want to build). Thanks all

I've used press wood before. Good plywood should be fine. I use an oak wardrobe now. Go for it. If your worried about it paint the inside with kilz then some flat white.

I was thinking something about that route, I was also thinking of caulking all the small cracks and seems in the interior the help ensure my air flow. I figure as long as the air is moving at least 400cfm for my 280cf room then my humidity should never raise above 55% unless I push it for veg. Even with a 65% humidity though, and I paint and seal the cracks, I should be just fine right? I feel like I'm just over paranoid at this point a bit

2x2 isd way too small....at the size a tent is ideal, but the real deal imo,...use marine grade ply and cover it with oil based white.. flat with high titanium paint

I was going to build the room 8x5x7, would 2x2 really be too weak? Or should I just go a little overboard and use 2x4 just for extra strength

NWbordergrower91 said:

I was thinking something about that route, I was also thinking of caulking all the small cracks and seems in the interior the help ensure my air flow. I figure as long as the air is moving at least 400cfm for my 280cf room then my humidity should never raise above 55% unless I push it for veg. Even with a 65% humidity though, and I paint and seal the cracks, I should be just fine right? I feel like I'm just over paranoid at this point a bit

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judging from your username I gather you are growing in the Pacific northwest?
Reason being is ambient humidity is ALWAYS going to be the biggest factor...
you can ventilate with a jetcraft powered turbine but if the air is humid, it won't make a difference.
Easiest route, but most expensive, as well as cost consuming in the long run is an air conditioner/dehumidifier.
But if you ambient humidity levels aren't bad, just get that fan going.

you are correct sir, I'm up in northwest WA so its always wet aside from summer for a short while. I did consider a dehumidifier for the room the actual grow room will be built in. To give the incoming air a bit of a buffer before its pulled in. Or if that isn't enough just running a small unit in the room itself.

I just finished building a 4X4X7 out of 2X4s. I don't think 2X2s would be strong enough to hold up the plywood I used. I used 2X2s to make a seal around the door frame. The screw nearly busted them in half, even predrilled. I don't see an 8X5X7 built out of 2X2s being very strong, but I am no expert. This is the first thing I have ever built out of wood. See my thread if you want some ideas. I can also send you the SketchUp file if you want to look over the plans.

https://www.rollitup.org/t/new-grower.877676/

bnestars said:

I just finished building a 4X4X7 out of 2X4s. I don't think 2X2s would be strong enough to hold up the plywood I used. I used 2X2s to make a seal around the door frame. The screw nearly busted them in half, even predrilled. I don't see an 8X5X7 built out of 2X2s being very strong, but I am no expert. This is the first thing I have ever built out of wood. See my thread if you want some ideas. I can also send you the SketchUp file if you want to look over the plans.

https://www.rollitup.org/t/new-grower.877676/

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I'm building 99% identical to yours honestly. I didn't think of the raised floor or the vents to allow air flow underneath the floor but I do really like the idea. I'm one for details.

I coated the bottom of my box with white silicone its reflective and water proof

You where talking about the whole box tho right?

2x2s are strong enough....have done several 4x4s, a 5x5, and a 6x8 using just 2x2s and 4x8 sheets of regular plywood. I painted with kilz and then flat white and had no moisture problems....

2 x 4's. better over than under built

Hit it with a couple coats of kilz and some quality flat white paint. No issues.

A decent intake filter can help prevent mold growth as well. Remember there are mold spores in the air of most environments. If you can filter the incoming air it will help. But if you use a good plywood like marine grade and also paint it with a good mold inhibiting paint you shouldn't have any issue.