Building a 4x6 hidden room

[budderfly]

I am able to grow only under the condition that it is extremely well hidden - as in, no visible entrance, no fan noise in the adjacent room, no warm walls, etc.

There is one space in my house that I think I can make disappear. My basement is finished, but the laundry room is not. The laundry room is long and the adjacent room is the downstairs 3/4 bathroom (toilet, sink, shower stall). This picture is looking directly at the back of the bathroom wall, the outside block wall is on the left and a wall supporting the stairs is on the right.

The goal is to flower with 1kw or 2x600's and have mothers, cloning, veg (trying to maximize production), and storage of nutrients etc. all in that space, and be able to stand in the laundry room without having any clue it's there.

I've been sketching it up in Google SketchUp. This is the space as it sits. 80" across the back of the bathroom wall from the concrete block to the face of the studs under the stairs. It's 53-1/4" deep from the face of the bathroom wall studs to the outer edge of the last stud under the stairs. Underneath the air ducts it is about 75" and in the taller part I can go up to 82" and that leaves room for the piping to travel along the trusses (82" is 1.5" under the trusses).

The first thing I have to do is move that bench out of the way, it's getting slid further down in the laundry room (plenty of room for it along the wall).

Next I'm going to extend the wall under the stairs by 10". This is as far as I can go and still get past the water heater and under the stairs (in the right of first pic). I would love to use the under stairs area, too, but that would kill the hidden aspect of this room.

After extending I will build the fake wall across. It will be complete along with dummy pipes and wiring to make it look legit.

Secret Entrance: I plan to leave one piece of drywall unsecured so it can be removed. It will be held in place by strong magnets. I am also trying to figure out how I might attach a latch to this panel to secure it in place, but I need to be able to open the latch from outside the room without it being discoverable.

The room will exchange air through the ducts with the rest of the house. I will be pulling air into the room from the return with a Solar & Palau TD-125 5" Mixed Vent inline and I will be exhausting it through a 8"x24" Phresh filter (750 cfm) with a 8" ValuLine inline (745 cfm) and out the duct that feeds the house with hot/cold air, the fan will be dialed down on a speed controller.

I've grown 3k in tents in this basement before, and I'm confident the house can handle being a lung for just 1k (3k needed a dehuey in fall & spring).

Hiding the fan noise is essential. I want the whole room framed in 2x4 filled with Roxul (mineral wool) insulation, which is heavy and sound deadening, plus very fire resistant. I plan to finish the inside of the room with 5/8 fire-rated drywall covered in Green Glue (sound dampening glue) and another layer of 1/2 moisture resistant drywall. The double-drywall layer with Green Glue should block a lot of sound - expect for where I have to cut openings into the ducts. For that, I plan to simply box it in with lots of insulation as best as I can, wrap the ducts themselves in some damping material (like dynamat). If needed, I'll buy duct mufflers, but I want to see if I really need them first.

The fake wall poses a problem. I'll need a second wall behind it that's insulated and holds the drywall.

The inner space after drywall and everything is 4'x6'.

I'm thinking that the removable panel on the outer fake wall will push in and hang off a cable on a rod so it can be pushed to the side in between the walls (like a sliding door, kinda). Then I'll put a similar door by building a panel on the inner wall that is held in with magnets, pushed in to remove, then pushed to the side like a sliding door. But the inner door will be thick and insulated, multiple panels of MDF board Green Glued together with soundblocking vinyl seals around the opening.

I'm still working out how I'm actually going to assemble all this, and how to fit all the grow areas into this space. I'll keep updating as the build out progresses over the following weeks. :)

 

[jagle]

amazing what your planning here, my only concern is that sound travels through objects no problem, its an air gap you want with nothing bridging that gap to ensure no sound travels..
cant wait to see it develop.
be a great achievement if you can pull it off

 

[sky high]

This is more of a bookshelf....but I immediately envisioned a shelving unit of some type on that wall that covers the door. You could put tools/etc on the shelves and it would blend in well...

http://www.instructables.com/id/Hidden-Door-Bookshelf/

 

[budderfly]

Sounds like a lot of work for just 4x6 of space. But yes from a framer you do want that air gap with no bridging for the best sound dampening. But are you going to be able to hang two 600w hoods fillter and have veg space and still be able to get in the room to work. I find my self working from out side the doors of my 4x8 tent when it is full of gear and plants all the time. But best of luck i will be stoping in to see how you make out with the room

I hear ya. 4x6 is a small amount of space.

The problem is I used to run 3k flowering in a few different tents, veg used to be in the bottom of that workbench even. But, something happened. Now the only way I can grow is to keep it completely hidden, and that's the only space that I can hide. I am certain I can fit 600w with veg, clone, etc - but I'd much rather try and cram in a 1kw, in a vertical with the light on a mover for example. I have a few inventive ways to jam in space for clone's and veg - keeping it compact with PL-L's. My goal is to have a new spot outside the home in a year and a half, anyway.

For flowering, I was thinking bare-bulb vertical, but I may have to settle for a flat scrog. We'll see, I can work out the interior of the room as I go and see how it is.

amazing what your planning here, my only concern is that sound travels through objects no problem, its an air gap you want with nothing bridging that gap to ensure no sound travels..
cant wait to see it develop.
be a great achievement if you can pull it off

Sound doesn't travel through everything equally. Each layer of drywall will dampen the sound, and the green glue between layers keeps the vibrations from the inner layer from traveling through to the outer layer. The studs will transmit some vibrations, but the Roxul mineral wool insulation will absorb a lot. The wall that faces the laundry room will be a double wall, with a couple inch gap between to provide that air space. The backside of the wall under the stairs will also be double-drywalled and green glued. The wall against the concrete block won't bleed much sound, and neither should the wall against the bathroom. The ceiling, however, might be problematic. It will be double-drywall, and I'm going to try and lay as much Roxul on top of it as I can.

This is more of a bookshelf....but I immediately envisioned a shelving unit of some type on that wall that covers the door. You could put tools/etc on the shelves and it would blend in well...

http://www.instructables.com/id/Hidden-Door-Bookshelf/

For this project I think it is best to keep it looking like it was by doing a fake bathroom wall. It would be much more noticeable if it became a tool shelf.

 

[jagle]

cool cool..
another thing, you are feeding the rooms exhaust back into the house, im sure youve grown before as youve mentioned in that space and are confident you can remove the smell completely? otherwise maybe exhaust it out where your dryer goes?

 

[sky high]

[quote="budderfly, post: 906119, member: 39374
For this project I think it is best to keep it looking like it was by doing a fake bathroom wall. It would be much more noticeable if it became a tool shelf.[/quote]

Sounds like you really don't need advice and have your mind made up.

good luck with those magnets....

 

[budderfly]

[quote="budderfly, post: 906119, member: 39374
For this project I think it is best to keep it looking like it was by doing a fake bathroom wall. It would be much more noticeable if it became a tool shelf.

Sounds like you really don't need advice and have your mind made up.

good luck with those magnets....[/quote]


Truth be told I do have my mind made up about that point. No offense, but my wife and I have discussed it at length and for many reasons feel it is best to mimic the existing wall - not least of which is the need to scavenge every inch, and the width of any shelving would come directly out of the interior of the room.

No need to be offended because I dismissed your fake shelving idea for this situation.

I also believe strong neodymium magnets will do a great job at holding a removable panel in place. The seam between panels will be behind 2x4's, and you simply drill a recess into the wood and glue the magnet in place. The panel won't budge without a significant amount of force, slide the panel aside and simply step between the studs into the room.

 

[sky high]

Words like "simply"(2x) and "wife" and phrases like "discussed at length" give me a better idea of the scenario at play here. Had you mentioned any of that in the first post I wouldn't have commented in the first place. Sure isn't the way it works around here...LOL.

Um....good luck.

 

[budderfly]

Words like "simply"(2x) and "wife" and phrases like "discussed at length" give me a better idea of the scenario at play here. Had you mentioned any of that in the first post I wouldn't have commented in the first place. Sure isn't the way it works around here...LOL.

Um....good luck.

No, I don't think you have an idea of the scenario at play here. We're a team and it's her passion as much as mine, but we had a security issue late last year and shut down the 3kw we had running. This is what we feel is necessary to be comfortable starting up again.

When is it you are going to start this build? i would like to see some pics of this door you are making if you pull it off it should be really cool. And i see it the wife sticking you in the small space lol.

It's in progress. I'm disassembling the bench to move it down further, and I just picked up the 1" XPS foam insulation and ordered the Roxul mineral wool insulation. There's a bit to do - splitting the studs ramset'd into the wall and grinding off the nails, then patching over it. Then I'll put the XPS up and attach the bottom plates, start framing.

My day job is on and off, and right now its on so the next week might not see a ton of progress.

 

[sky high]

LOL. Just funnin' with ya about the wife....but after 32 years of marriage...I know what I'm talkin about with "the scenario". You been married 32 years? No?? I rest my case. LOL

Thankfully, HPS gives my wife a headache...and thus...she isn't involved in my garden other than asking when I'm gonna roll another joint and get her high. LOL.

Good luck with the build. I'll be watching for the bud shots 'cus in the end, that's what makes it or breaks it and makes an idea a good one or a bad one....

be safe

s h

 

[fishwhistle]

32 years this month here sky,I can smell what the rock is cookin...

 

[budderfly]

LOL. Just funnin' with ya about the wife....but after 32 years of marriage...I know what I'm talkin about with "the scenario". You been married 32 years? No?? I rest my case. LOL

32 years this month here sky,I can smell what the rock is cookin...

Lol, I hear ya guys. I just get a bit defensive cause I know the type of women that give a grower problems, and my old lady's a champ. She's on the bay looking for genetics, and her first idea was to set up larger in an industrial space. ;)

We've only been together 4 years, though, so who knows what it'll be like after 20 more!

I just finished a work project last night so I'll be down there today. And really, the book case idea is cool and I'm open to all ideas to see what I can take from them.. It's just for this space I don't see it - the width of the shelves really would have to come out of the room, because I have to leave a gap to get behind the water heater and under the stairs.

 

[sky high]

The kind of woman who can give a grower problems is basically >any< woman.
Women/broken relationships have taken down more gardens than cops ever have... :eek:

I only trust mine to know my shit 'cus I met her in 8th grade in 1971 when she sold me my first hit of 'cid. Heehee... Even then, I figure i gotta have some space...and my grow is >my< space.

My old lady pays (all the bills!) for the electric and the seeds I buy and as long as I keep her boned and stoned...all is well. LOL.

but yeah...they are all different and so are the workarounds....LOL.

 

[Papa]

making a room stealth is a combination of design and attention to construction details. caulk the baseplates to the floor. double walls (with NOTHING touching between them) are terrific. put 3/4" cdx on the wall before the drywall . . . if you are SERIOUS about absolutely no sound, make it 1-1/8" T&G (typically used for sub-floors). walls are basically drums, you wanna make them as rigid as possible. leave a 16d gap at all ply edges and caulk the gap. if you are REALLY SERIOUS about absolutely no sound, wrap and solder lead sheeting between your double walls. don't laugh, it's done all the time for serious acoustic security in some applications. you seem to be avoiding your ceiling. whatever you do for your wall solution should also be done for the ceiling. basically, you're building an entire new freestanding envelope within your existing room.
for your inline fan, begin with Trichromefan's muffler:
https://www.thcfarmer.com/community/threads/diy-fan-muffler.24352/
then make the air go around a couple of padded corners before exhausting. if all this is done, your weak spot will be your holes (pun intended for my buddy sky high) . . . . as in your pass-thrus and door (i assume you know better than to recess electrical in a stealth room). since i often want to modify what's going in and out, i like to permanently mount short pieces of ABS or SDR (2", 3", 4") through the wall with a hole saw and caulk around, slip my pipes/conduits, etc. through the ABS/SDR, and fill around the pipes/conduits with handfulls of plumber's putty. 'sounds like you have your own ideas about the door. good luck.

 

[budderfly]

making a room stealth is a combination of design and attention to construction details. caulk the baseplates to the floor. double walls (with NOTHING touching between them) are terrific. put 3/4" cdx on the wall before the drywall . . . if you are SERIOUS about absolutely no sound, make it 1-1/8" T&G (typically used for sub-floors). walls are basically drums, you wanna make them as rigid as possible. leave a 16d gap at all ply edges and caulk the gap. if you are REALLY SERIOUS about absolutely no sound, wrap and solder lead sheeting between your double walls. don't laugh, it's done all the time for serious acoustic security in some applications. you seem to be avoiding your ceiling. whatever you do for your wall solution should also be done for the ceiling. basically, you're building an entire new freestanding envelope within your existing room.
for your inline fan, begin with Trichromefan's muffler:
https://www.thcfarmer.com/community/threads/diy-fan-muffler.24352/
then make the air go around a couple of padded corners before exhausting. if all this is done, your weak spot will be your holes (pun intended for my buddy sky high) . . . . as in your pass-thrus and door (i assume you know better than to recess electrical in a stealth room). since i often want to modify what's going in and out, i like to permanently mount short pieces of ABS or SDR (2", 3", 4") through the wall with a hole saw and caulk around, slip my pipes/conduits, etc. through the ABS/SDR, and fill around the pipes/conduits with handfulls of plumber's putty. 'sounds like you have your own ideas about the door. good luck.

Lots of good advice, thank you.

The baseplates will be applied with construction adhesive and tapcons and all edges are being sealed with acoustical sealant. The fake wall will have a 2" gap with no contact between it and the inner wall that is insulated with Roxul and covered with double layer of material separated by Green Glue.

The Green Glue can work between any wall materials. Usually it's used between drywall, but I was considering MDF. I wonder if CDX or MDF is better for sound attenuation? (I would guess MDF).

Green Glue isn't as effective as lead sheats, but it's supposed to be close. I was thinking about a lead sheet curtain over the door through the inner wall, cut oversize to cover the edges.

The ceiling will get the same treatment as the walls - double layer with Green Glue. I'm also installing Roxul between the joists, 2 maybe 3 layers, literally filling the space up - particularly around where I enter and exit the ducts. I'm also applying a dynamat like product to the ducts.

Thanks for the link about the muffler, intake and exhaust will be (obviously) my biggest sound issues. And of course no recessed electric. ;) One conduit coming in probably feeding a little panel. All I should need is the open double 20A that used to feed my dryer before I switched to a gas one.

My idea for the inner door (the one that is really to resist sound) is to make it out of multiple layers of MDF with Green Glue inbetween, with a large overlap on the inner surface using an acoustic foam strip for sealing the door opening. I may also try a heavy vinyl or lead curtain, but I'm guessing the intake and exhaust will be a bigger problem.

I'm definitely open to ideas about the door, it just has to conserve space. For example, I'm planning for the door to slide away to the side rather than swing open on hinges.

I also considered hanging the ceiling from acoustical clips, but 1. I wasn't sure if it would have that much effect if I didn't do the walls too (too much space lost) and 2. I wasn't totally comfortable hanging the filter... it should be ok, Phresh's are light, but I'd have to be sure to spread the load over a few clips.

 

[budderfly]

Here's a little update. I started taking the bench apart, but it appears to have been built in place, with lots of overlapping 2x4's all screwed into each other. I'm not going to get it un-screwed from the studs on the walls without taking the entire thing apart - the bottom's loose, but there's a lot of screws hidden under the top:

And here's where the bench is going, just sliding down a couple feet:

I pulled a few photos out of some old videos. Here's a grainy shot of what used to be in that empty spot and underneath the bench:

So what I think I'll do after removing the pegboard is take a circular saw and just zip through the 2x4's above the bench so I can pull the whole thing off the wall and then remove the bottoms of the studs.

Here's where it sits right now:

And, lastly, I'll throw these in. This is what used to be in another room of the basement, 2 tents each with 1kw:

 

[budderfly]

Another little update. Got the bench off the wall. Took the circular saw, set it just so, and zipped the 2x4's in half right above the bench. Couple tugs and a little prying and the bench popped right off the wall.

 

[ttystikk]

I can't help but wonder what sort of security issue would stop you from growing inside your house but unhidden- and yet hiding the grow in the same place makes sense. Not my business, just curious.

The advice you've gotten already sounds top notch, and way over my head! I'm taking notes for when the time might come for me to get quiet.

Good luck and I'll be subbed for the action!

 

[SodaLicious]

I can't help but wonder what sort of security issue would stop you from growing inside your house but unhidden- and yet hiding the grow in the same place makes sense. Not my business, just curious.

The advice you've gotten already sounds top notch, and way over my head! I'm taking notes for when the time might come for me to get quiet.

Good luck and I'll be subbed for the action!

My guess would be children? lol I know I have to keep mine secret due to children that may come over at anytime....

 

[EVOKE]

i wish i had a basement.... that would be the ultimate for me.... looking good there budderfly..