Building a grow room advice

[ZoomZ06]

Hey everyone, I am ACMPR license and legally allowed to grow 49 plants indoors. I have been using tents for a few harvests but an opportunity has risen to be able to build a fairly large grow room (20’x20’). I’d say I’m a moderate knowledge grower so I know the requirements needed for the room, but my question is, does any one have an experience in building? What are issues that I should look out for? Essentially I want to build this once and build it right. Just looking for insight to make sure I do it all properly.
As of right now my idea would be to section off maybe a 10x5 area for vegging room and have the rest as a flowering room that’s about as much thought as I’ve put into it. Building wouldn’t start until spring so I have lots of time to put into proper planning

 

[Gabby987]

Hey everyone, I am ACMPR license and legally allowed to grow 49 plants indoors. I have been using tents for a few harvests but an opportunity has risen to be able to build a fairly large grow room (20’x20’). I’d say I’m a moderate knowledge grower so I know the requirements needed for the room, but my question is, does any one have an experience in building? What are issues that I should look out for? Essentially I want to build this once and build it right. Just looking for insight to make sure I do it all properly.
As of right now my idea would be to section off maybe a 10x5 area for vegging room and have the rest as a flowering room that’s about as much thought as I’ve put into it. Building wouldn’t start until spring so I have lots of time to put into proper planning

Hi there. Happy Thanksgiving.
I am a new grower, but have tons of experience building. I build both of my grow rooms in my basement.
What would you like to know?
Are you building in basement, Attic,anywhere in your home, or are you planning to add a separate buiding?

 

[Weaselcracker]

10x 5 for a veg room is nice. I can’t see you needing all that space for veg, but usually you’ll want to store nutrients and whatnot there as well. How big for flowering ?

Don’t forget to plumb drains into the floor.

 

[Backlipslide]

Great question gabby!!

I would also like to know if it’s in a basement attic tent etc.... are you building the walls and planing on using drywall inside the room? How do you plan on finishing?

if you’re using a drywall material I’d suggest buying aqua board which is mold resistant rather then normal drywall.

you could also buy some panda film and line the walls with it...

I built my tent out of 3/4” pvc piping and furniture grade 3 way elbows. I rebuilt it a few times, mainly to make it bigger each time... but at first I lined my tent with space blankets, and it worked. Paid for its self and then some. Then the final rebuild I built it out of panda film.

 

[ZoomZ06]

I guess a little more info would have been more useful for all of you lol
It will be a separate building. We will be building it ourselves. So my thought was for it to be insulated up to house coding obviously and using the same dry wall as you would in a bathroom to prevent mold. Also would most likely be adding reflective material/Mylar over top of the dry wall. There will be absolutely no windows, and one way in one way out to eliminate any possible chance of light leaks. for the flooring, my first idea would be to use basement sub flooring to give a bit of a raise to the floor in case of any water leaks it would keep any damage minimal. Then I top of the sub flooring putting a linoleum over top.
@Weaselcracker yes I figured I could use it as a storage room as well as the veg room that way I can utilize as much space as possible in the flower room.

so I guess some of the questions I’d be looking at would be ventilation set up. I’d assume a wall extraction fan would be best for exhausting hot air out, but would I also need an intake fan to bring fresh air from outside the building in? I know I would need a smaller CFM rated fan for the intake to be able to maintain a NPD inside.
For controlling temperature I figured I’d get a portable a/c unit or 2 to control the cooling side and would a couple decently sized space heaters for heating. Would that be ideal? I imagine installing an a/c and furnace would be overkill.

Sorry for the long winded message, just trying to cover as much ground as possible

 

[Gabby987]

Veg room. Under stairs.
Mould resistant 1/2" drywayy.
Shiny insulation.
Vented to flower room
3x12 area
Concrete floor, plants on platforms

 

[Gabby987]

Flower room.
10x12
Exposed ceiling joists
Vented outside through basement window.

 

[Gabby987]

I guess a little more info would have been more useful for all of you lol
It will be a separate building. We will be building it ourselves. So my thought was for it to be insulated up to house coding obviously and using the same dry wall as you would in a bathroom to prevent mold. Also would most likely be adding reflective material/Mylar over top of the dry wall. There will be absolutely no windows, and one way in one way out to eliminate any possible chance of light leaks. for the flooring, my first idea would be to use basement sub flooring to give a bit of a raise to the floor in case of any water leaks it would keep any damage minimal. Then I top of the sub flooring putting a linoleum over top.
@Weaselcracker yes I figured I could use it as a storage room as well as the veg room that way I can utilize as much space as possible in the flower room.

so I guess some of the questions I’d be looking at would be ventilation set up. I’d assume a wall extraction fan would be best for exhausting hot air out, but would I also need an intake fan to bring fresh air from outside the building in? I know I would need a smaller CFM rated fan for the intake to be able to maintain a NPD inside.
For controlling temperature I figured I’d get a portable a/c unit or 2 to control the cooling side and would a couple decently sized space heaters for heating. Would that be ideal? I imagine installing an a/c and furnace would be overkill.

Sorry for the long winded message, just trying to cover as much ground as possible

Will you be pouring a concrete foundation?

 

[Weaselcracker]

You don’t need Mylar or anything like that. White paint works better.

Some sort of built in drainage seems pretty essential.

One door to the main grow is nice but if I rebuilt I would have separate doors for veg and flowering. Maybe you can make a third area as an entrance hallway in that case.
You have to be able to control the lighting schedule and you don’t want to have to turn the lights off in veg to get through to the flowering room at odd times, as I do....

 

[Sativa1970]

I am a general contractor and on room version 3.0. There is always just one more upgrade. Floor drains,big sink with filtered water,shelving/storage,foam(waterproof) insulation walls,venting. As for the % of veg to flower it depends how you are rotating crop and don't forget to leave walkways. Seedlings take little space but there need for space grows.Flowering plants generally double in size during the stretch. basic math flowering room should be double the veg room.If you are cloning, clone veg 30 days+/- plants flower in 60+/-. So what you are growing and how are the biggest factors. Soil or hydro?

 

[bluter]

if you can : room in room style build. inner rooms grow spaces. outer room is a lung room. lung room scrubbed and exhausted to outdoor. solves so many problems.

edit : can be accomplished with tents in a main lung room as well.

 

[Southerncough]

Read this thread...every single word.
You won't be sorry!

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Honestly, I had planned to start a build thread nearly a year ago, however we have been SO busy trying to pull this dream of ours off, time has literally flashed by. Now that the building is up, it's time to start to document this biggest venture of either of our lives . I guess I need to offer...

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[Weaselcracker]

Also- Yes you need fresh air. Most people I know don’t use a fan on the air intake. Just an out-vent fan and a passive intake.

Put in a decent floor. You shouldn’t have to be worrying about any ‘water leaks’- that will get old very quickly. Set it up so you can water, clean and hose things down at will and water goes down the drains.

 

[ZoomZ06]

Not much thought has been put into it but I doubt we’d go with concrete. Probably wood frame with spray foam insulation, sub flooring and then linoleum on top of that.
White paint noted lol! I thought that would be good enough but wasn’t sure. I knew Mylar would be good either way but white paint seems to be more cost effective lol
I understand there will always be upgrades, but if I can eliminate as much as possible and leave less to do in the future I’d be happy lol yes it would be a door into the building into a hallway where thered be separate rooms for each stage. I’ll be doing soiled pots and more than likely will be a mix between seeds and clones

 

[ZoomZ06]

Side note thank you all so much for your advice this is more help than I’ve been able to read up on!

 

[bluter]

Also- Yes you need fresh air. Most people I know don’t use a fan on the air intake. Just an out-vent fan and a passive intake.

Put in a decent floor. You shouldn’t have to be worrying about any ‘water leaks’- that will get old very quickly. Set it up so you can water, clean and hose things down at will and water goes down the drains.

good points.

honestly, we never used active intake on a larger grow though.

it was housed inside a larger semi-urban building, and the exhaust pulled so much passive intake in we did not find it necessary. not something everyone can rely on, and we scrubbed air so well no one knew on the other side of the wall.

 

[ZoomZ06]

good points.

honestly, we never used active intake on a larger grow though.

it was housed inside a larger semi-urban building, and the exhaust pulled so much passive intake in we did not find it necessary. not something everyone can rely on, and we scrubbed air so well no one knew on the other side of the wall.

Smell will not be a worry as I’m in the middle of a 16 acre field with no neighbours lol
Without using an active system how did you allow fresh air in? Just a vent inserted in the wall? I’d assume some sort of flap system to not allow light in through it?

 

[Gabby987]

Definitely separate rooms. My biggest challenge was light proofing the flower room. Black caulk and black gorilla tape are your best friends, as well as weatherstripping around door frame.
I found no need for active intake fan. An outside opening with a screen sheltered by rain was enough.

 

[Rexer]

Not much thought has been put into it but I doubt we’d go with concrete. Probably wood frame with spray foam insulation, sub flooring and then linoleum on top of that.
White paint noted lol! I thought that would be good enough but wasn’t sure. I knew Mylar would be good either way but white paint seems to be more cost effective lol
I understand there will always be upgrades, but if I can eliminate as much as possible and leave less to do in the future I’d be happy lol yes it would be a door into the building into a hallway where thered be separate rooms for each stage. I’ll be doing soiled pots and more than likely will be a mix between seeds and clones

Flat white paint at that. The flat white has the highest reflectivity.

 

[bluter]

Smell will not be a worry as I’m in the middle of a 16 acre field with no neighbours lol
Without using an active system how did you allow fresh air in? Just a vent inserted in the wall? I’d assume some sort of flap system to not allow light in through it?

we pulled from the interior. passive vents inside the building on the main rooms. all on the inside. nothing fancy. room in room is easy. external rooms have no need of being exceptionally isolated as far as light or air tightness.

inner rooms don't have to be as air or light tight as a single exposed room would either. avoids a lot of problems.