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Building a 4x6 hidden room
- Thread starter budderfly
- Start date
budderfly
Active member
I've spent some time diddling in SketchUp. I should've been working. It's all starting to shape up in my head.
I laid out some frame for a soffit around the vents. It is 3.5" deep underneath and on the side of the vents so that I can fill the space with Roxul. I brace the 2x4's against the existing wall studs, should be nice and rigid.
The front of the soffit frame overlaps the wall, with a 1/2" gap. The first layer over the frame will be OSB all around the room so that I can easily screw the drywall and future shelving & fixtures anywhere. The walls will all be a layer of 1/2" OSB and two layers of 5/8" Type-X drywall (Green Glued), the ceiling and the walls of the soffit will all be a layer of OSB and three layers of 5/8" drywall.
There's a 4.5" gap between the fake wall and the inner wall. The inner wall will be covered with a 1" rigid foam insulation to help prevent a warm wall that might be visible on a thermal camera. The fake wall will be covered with 1/2" cement board and drywall - and behind that a solid layer of 5/8" Type-X drywall Green Glued on. This should leave space for a panel of the fake wall to push in and slide between the fake and inner walls.
Here's a shot of the whole frame.
And a shot minus the fake wall but with the vents and pipes running along the joists.
The interior foot print after all the walls are up should be 4'x6' dead on the nuts.
I laid out some frame for a soffit around the vents. It is 3.5" deep underneath and on the side of the vents so that I can fill the space with Roxul. I brace the 2x4's against the existing wall studs, should be nice and rigid.
The front of the soffit frame overlaps the wall, with a 1/2" gap. The first layer over the frame will be OSB all around the room so that I can easily screw the drywall and future shelving & fixtures anywhere. The walls will all be a layer of 1/2" OSB and two layers of 5/8" Type-X drywall (Green Glued), the ceiling and the walls of the soffit will all be a layer of OSB and three layers of 5/8" drywall.
There's a 4.5" gap between the fake wall and the inner wall. The inner wall will be covered with a 1" rigid foam insulation to help prevent a warm wall that might be visible on a thermal camera. The fake wall will be covered with 1/2" cement board and drywall - and behind that a solid layer of 5/8" Type-X drywall Green Glued on. This should leave space for a panel of the fake wall to push in and slide between the fake and inner walls.
Here's a shot of the whole frame.
And a shot minus the fake wall but with the vents and pipes running along the joists.
The interior foot print after all the walls are up should be 4'x6' dead on the nuts.
budderfly
Active member
Wish I could edit posts...
Some may worry about OSB off gassing formaldehyde but I just happen to have a bunch that's been in my garage for 2 years. It'll be sandwiched between drywall and roxul insulation anyway.
I also decided I'm going to order acoustic egg crate foam and make my own duct mufflers, as well as line the existing ducts in both directions from where I tap the intake (from the return) and the exhaust (into the supply). I'll put foam on the top and bottom of the ducts, but I think leave the sides bare (they recommend like 70% coverage anyway). Should be good and quiet that way - using insulated duct with a corner or two into a muffler and out into foam lined duct.
Some may worry about OSB off gassing formaldehyde but I just happen to have a bunch that's been in my garage for 2 years. It'll be sandwiched between drywall and roxul insulation anyway.
I also decided I'm going to order acoustic egg crate foam and make my own duct mufflers, as well as line the existing ducts in both directions from where I tap the intake (from the return) and the exhaust (into the supply). I'll put foam on the top and bottom of the ducts, but I think leave the sides bare (they recommend like 70% coverage anyway). Should be good and quiet that way - using insulated duct with a corner or two into a muffler and out into foam lined duct.
Builtaforest
Member
Admire your ethic
I'd do short too, no need for extra space above it. let the plants (or equipment..) use the extra space in the other part of your space.
good luck with your project. I'll follow this! Great job till now!
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Superhoops
Member
Subbed to this....I have a secret room in my cellar also. You're one looks as though it could be epic.
GetUpStandUp
Active member
Nice plans, work area, and idea, if I ever go back inside this is a solid idea, if you do it like this, cant wait for the crisp finish, and nice trim work to help hide seams.
gtgio
Member
Damn, those are cool too. It looks like the ballast is integrated into this unit? That's pretty much the only difference I guess
In my own room i have use soundproofing bord along with 3 5/8 layer of gypsum all white tiled (tile are for fire hazard "mostly bad for sound proofing")Room is almost stealth too;I.m.h.o. you seam to have covered all other thing (Water in/out,insulation,sound proofing,power,stealth)maybe also checking other area like security,fireproffing,water proofing .
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budderfly
Active member
My order from horticulture source came today. Still said "processing" on their site but UPS just dropped it off. I'm getting very excited; got a few more days of real work to do and then I'm free for basically a month I'm gonna pound this project.
Some Strapped spilled onto my jug. Man is that stuff stinky!
Also today I put in an order for acoustic egg crate foam and some adhesive. $33 for a 1-1/2"x72"x80" sheet (I got two for the free shipping).
One sheet should be enough to make both mufflers - for the 6" intake line I'll use a 10" diameter solid section of duct pipe and for the 8" exhaust I'll use 12" diameter - then just cut the foam to size and glue it around the inside of the pipe and crimp it shut, and reducers on the ends.
With the foam in the middle, the diameter to the tips of the egg crates should be 7" and 9" - the larger diameter of the muffler helps reduce the sound (air velocity drops). After making the mufflers there should be enough left of the one sheet to also have about 18 feet of 12" wide strips to line the inside of the house's ductwork.
I also almost forget about the intake filter. Phresh makes some nice intake filters and I'm going to get the 6"x12" (~460 cfm iirc). It'll be a Solar & Palau TD-125 (5") that I already have feeding the intake for now. So I have to put in another order for the intake filter and some 6" & 8" backdraft dampers - if the fans are off the dampers keep the central air from pulling air out of the room. Another $125 for all that. Almost there...! Except genetics, fuck
Home depot run tomorrow. At least I have some store credit to burn.
Yep, no dinking around wiring it up. Plug in and go. I wonder if ahsupply dropped their prices lately, the 55w kits seem cheaper than I remember, maybe not.
Thanks, I checked out your threads. I wish I had a bigger space like that.
Fire-proofing is provided by the two layers of fire-rated drywall and the Roxul insulation which is also highly flame resistant. The room should actually contain a fire very well - I think literally the entire house could burn down around it and the room would still stand.
I also plan to get one of those automatic extinguishers - like a flame defender. Just not quite yet, they aren't that expensive but
For water proofing I will line the floor with thick shower pan PVC (similar to pond liner, a bit thinner but still good). The walls will be painted bathroom white with a mold-inhibitor.
It's not really waterproof, but I think it'll hold up for a while.
Some Strapped spilled onto my jug. Man is that stuff stinky!
Also today I put in an order for acoustic egg crate foam and some adhesive. $33 for a 1-1/2"x72"x80" sheet (I got two for the free shipping).
One sheet should be enough to make both mufflers - for the 6" intake line I'll use a 10" diameter solid section of duct pipe and for the 8" exhaust I'll use 12" diameter - then just cut the foam to size and glue it around the inside of the pipe and crimp it shut, and reducers on the ends.
With the foam in the middle, the diameter to the tips of the egg crates should be 7" and 9" - the larger diameter of the muffler helps reduce the sound (air velocity drops). After making the mufflers there should be enough left of the one sheet to also have about 18 feet of 12" wide strips to line the inside of the house's ductwork.
I also almost forget about the intake filter. Phresh makes some nice intake filters and I'm going to get the 6"x12" (~460 cfm iirc). It'll be a Solar & Palau TD-125 (5") that I already have feeding the intake for now. So I have to put in another order for the intake filter and some 6" & 8" backdraft dampers - if the fans are off the dampers keep the central air from pulling air out of the room. Another $125 for all that. Almost there...! Except genetics, fuck
Home depot run tomorrow. At least I have some store credit to burn.
Yep, no dinking around wiring it up. Plug in and go. I wonder if ahsupply dropped their prices lately, the 55w kits seem cheaper than I remember, maybe not.
Thanks, I checked out your threads. I wish I had a bigger space like that.
Fire-proofing is provided by the two layers of fire-rated drywall and the Roxul insulation which is also highly flame resistant. The room should actually contain a fire very well - I think literally the entire house could burn down around it and the room would still stand.
I also plan to get one of those automatic extinguishers - like a flame defender. Just not quite yet, they aren't that expensive but
For water proofing I will line the floor with thick shower pan PVC (similar to pond liner, a bit thinner but still good). The walls will be painted bathroom white with a mold-inhibitor.
It's not really waterproof, but I think it'll hold up for a while.
Tagged,i like the way you do it
Im going to read this later, after my chores are done.
Thanks for using Google Skethup its a good tool for all to use!
Thanks for using Google Skethup its a good tool for all to use!
budderfly
Active member
Sorry for the lack of progress folks. It's about to kick into high gear this week though. Though I'd drop in and show you the magnets I got to hold the false panel in:
I was able to find countersunk magnets in a variety of sizes, circular and rectangular. Circular is easy to countersink in wood (spade bit). Not sure what strength I really need, so these sizes are a starting guess.
I also cancelled my egg crate foam order and decided to simply buy the duct mufflers. It turns out that 12"-8" and 10"-6" reducers are crazy expensive ($20 each) so it's actually more expensive to build one. Also, Phat makes some better (imho) mufflers that use glass pack instead of foam. The foam has an expected life of about 5 years (probably less used in the exhaust of a grow, lol), whereas the glass pack should last much longer.
I decided the egg crate wasn't appropriate to line my hvac ducts with, since it would need replacing maybe 5 years or less down the road. There are products to line ducts with, but I cannot find them for purchase in small quantities.
I was able to find countersunk magnets in a variety of sizes, circular and rectangular. Circular is easy to countersink in wood (spade bit). Not sure what strength I really need, so these sizes are a starting guess.
I also cancelled my egg crate foam order and decided to simply buy the duct mufflers. It turns out that 12"-8" and 10"-6" reducers are crazy expensive ($20 each) so it's actually more expensive to build one. Also, Phat makes some better (imho) mufflers that use glass pack instead of foam. The foam has an expected life of about 5 years (probably less used in the exhaust of a grow, lol), whereas the glass pack should last much longer.
I decided the egg crate wasn't appropriate to line my hvac ducts with, since it would need replacing maybe 5 years or less down the road. There are products to line ducts with, but I cannot find them for purchase in small quantities.
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budderfly
Active member
Weird, the link for the magnets is supposed to be: http://www.kjmagnetics.com/proddetail.asp?prod=RE22CS-P&cat=173
Can't edit posts sorry
Can't edit posts sorry
GetUpStandUp
Active member
Magnets, wow great idea indeed, I had just watch this video on some guy who created these two magnets and they made a circle movement depending how close you put them, it was really cool, he was looking for someone to pay for or help with getting it funded or something like that, but magnets are very much link to awesomeness, here again something so simple we all played with before can be used for so many great things.
Great too see this thread took a step out of the norm, and into the different and not tredded path, cant wait to see the end product.
Great too see this thread took a step out of the norm, and into the different and not tredded path, cant wait to see the end product.
Reflectix is cheap and works great!
budderfly
Active member
I meant a product for sound absorption. Reflectix will not effectively absorb sound when used to line duct.
I'm talking about products like the QuietR line up from Owens Corning, for example: http://commercial.owenscorning.com/assets/0/321/335/4f424891-dad1-40ed-b49f-a11ff8be491a.pdf
budderfly
Active member
Ok its been a while since I've updated, so this will be a long post (or several, lots of pics).
I ended up finding a local place that sells a similar acoustic duct liner by the linear foot in 48" width (instead of by the 100' roll, lol I need like 10').
Wait til you guys see how I hookup the ventilation it'll be off the hook I promise.
Ok, so when we left off I had just removed the workbench from the wall. I removed all the studs except for two - one with the outlet in the way (I can't kill the power right now long story), and the one next to it partly because it's got a bunch of hammered over ramsets and partly because I can line it up and reuse it.
There was a bunch of holes in the block where I removed and ground off ramsets.
Since it's a below grade wall I thought I should get hydraulic cement to patch with, but the only bucket I saw is a shit load of cement. I only used like 2 or 3 cups.
First time ever working with concrete so it's a pretty mediocre job. The stuff set really fast and the water ratio they listed was totally not enough.
I ended up finding a local place that sells a similar acoustic duct liner by the linear foot in 48" width (instead of by the 100' roll, lol I need like 10').
Wait til you guys see how I hookup the ventilation it'll be off the hook I promise.
Ok, so when we left off I had just removed the workbench from the wall. I removed all the studs except for two - one with the outlet in the way (I can't kill the power right now long story), and the one next to it partly because it's got a bunch of hammered over ramsets and partly because I can line it up and reuse it.
There was a bunch of holes in the block where I removed and ground off ramsets.
Since it's a below grade wall I thought I should get hydraulic cement to patch with, but the only bucket I saw is a shit load of cement. I only used like 2 or 3 cups.
First time ever working with concrete so it's a pretty mediocre job. The stuff set really fast and the water ratio they listed was totally not enough.
