# False Floor Design - Any Issues? (pics)



## blindbug

I need to build up a false floor in the trunk of my Altima... it will be my first time doing this. Preferably, I would like to keep my spare tire and have relatively easy access to it. When I look at the floor itself, it steps down a bit from the front (closer to the cab) to the back, probably a little under 2" of drop. This means I need to raise the far rear of the trunk up by 2" and then as I get closer to the far front, step off the height... as to make it a level surface.

Below are some mock ups I did in photoshop of what I think would work for this, but I wanted to get some insight as to what issues I might run into with this type of setup, if any. Thanks to anyone with suggestions on improvements!

*A few questions right off the bat:*
• What weight of MDF should I be using here? I was thinking 3/4" for the beams and the amp rack flooring, and 1/4" for the actual false floor.
• Do I need to attach the false floor to the support beams? If so, is there a good way to make it easily removable?
• I was thinking of attaching a piano hinge to the split, to allow easy access to the amp for adjustments... any issues there?

*With the false floor on*. Because of the size of the floor, I would need to split it down the middle:









*Underneath the false floor*. You can see where the split would be. Do I need to attach the flooring to the beams that are supporting it? Any way to attach them without issues in removal?









*The sub-flooring*. Do I even need the 3rd beam across the top here? How about to the left and right... is it necessary to extend the beams further?


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## ryan s

Good PS skills 

I would avoid MDF in the trunk and go with some plywood, preferably birch. MDF is like a sponge...even a bit of water will warp it. 1/2" should be enough...if you're not going to put heavy stuff back there, your design should support 1/4" birch. Then use some 2x4s for the supports...or some similar wood. 

Not only will it be lighter, but also won't soak up water. Can't wait to redo mine, since it's only MDF...

The rest of your design looks good, and I'm definitely going to hinge it. I'm still undecided on how it will be bolted down...there HAS to be some holes drilled from the factory...or use the factory spare tie down.


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## jf2oo6

Gonna be doing something very similar to my altima hopefully this weekend. Will be tuning into this for updates. Will you post pics on here or in your build log?


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## Torquem

Holy crap. Nice PS skills


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## Bluto Blutarsky

Great plan. I will also suggest doing the floor in thin plywood.


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## Avernier

i just did a pretty indepth false floor in my gf's car, and even with a fan i'm having crazy overheating issues. to the point that the amp will burn you. be generous with your ventilation in there.


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## blindbug

Thanks for the suggestions guys. I was planning on starting some work on this today, but it looks like rain. That probably won't stop me from getting out to Home Depot to source some lumber though!

Thanks for the PS kudos as well. I've been dabbling in Photoshop for a long time now and have been getting a decent understanding of vector graphics over the last year or (2). In that picture above, the amp is all vector as well. 




jf2oo6 said:


> Gonna be doing something very similar to my altima hopefully this weekend. Will be tuning into this for updates. Will you post pics on here or in your build log?


I'll probably post the end results to both places. I like to close out a post so people who find it in a search aren't left hanging, trying to figure out what worked and what didn't. Feel free to post your results as well, since I might not get to my floor now until a week or (2) since it's raining on my last free day for (2) weeks.


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## jf2oo6

Just finished mine today. Pretty similar to what you were thinking of. I might have even stole a few ideas from you.


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## InfiniteHigh

I was thinking about doing the same thing with my amp and throwing plexi over it. Maybe even puts some lights around it.


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## jf2oo6

i thought about lights too, but for now just wanted to keep it clean and simple. might be another project in the future.


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## 94VG30DE

Is there factory carpet that goes over that? B/c if there is carpet, I see no reason to do a piano hinge. Just leave the panels separate, and it makes them easier to extract when necessary.


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## jf2oo6

94VG30DE said:


> Is there factory carpet that goes over that? B/c if there is carpet, I see no reason to do a piano hinge. Just leave the panels separate, and it makes them easier to extract when necessary.


I agree. No hinge in my trunk. The whole thing is made of 4 panels. The 2 flaps on the left and right, and the front and back. My front and back are split around the same place as your pic. All four pieces are attached with the carpet. So when they are in you cant see any lines, but if i have to remove it I can just fold it all up and take it out as one piece. Works great. I can also get to the spare tire, or make amp adjustments by just folding up the flaps and lifting the front.


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## 94VG30DE

jf2oo6 said:


> I agree. No hinge in my trunk. The whole thing is made of 4 panels. The 2 flaps on the left and right, and the front and back. My front and back are split around the same place as your pic. All four pieces are attached with the carpet. So when they are in you cant see any lines, but if i have to remove it I can just fold it all up and take it out as one piece. Works great. I can also get to the spare tire, or make amp adjustments by just folding up the flaps and lifting the front.


That is actually more slick than what I had in mind! Do you have issues with the board peeling away from the carpet? What did you use as an adhesive? Seems like this would be the ideal solution as long as you have space to fold things up.


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## jf2oo6

I used a spray adhesive. And I dont think peeling will be a problem as the panels will not be folded often at all. only as often as i get flats. i have no other reason to lift up the floor.


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## jf2oo6

Ok blindbug after looking at your pic again I see that I lied. lol. My split is not in the same spot as yours. My front and back pieces actually split further back, right where the hole starts for the spare tire. I went with that spot because that is also where the trunk drops off about an 1". So using that spot I was able to make the whole trunk level.

Btw if you are just trying to hide that amp, the design you have would be perfect, and very easy to do. For your top board just use the trunk mat that came with the car to trace all the edges and outline. Everything else is fairly straight forward and easy. The hardest part for me was making the cutouts to mount the amp flush.


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## blindbug

Awesome jf2006, I actually saw your post on another forum and was thinking that it looked extremely close to the design that I had posted here! It's good to see the design in a real-world environment, and I like how you did the 'hinge' to connect each of the pieces. In my last car, I used a piano hinge to connect all the individual pieces together and it worked well. The only issue is finding a piano hinge in the right configuration (flat, with the round piece pointing TOWARDS the wood, so there is no bump in the carpet.

Thanks for the suggestions guys, I think I will also be adding a fan to my design, something close to the rear of the car to draw air across the amps.


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## awash242

This is a basic question, but how do you guys get the measurements of the contours so well? I want to do something similar and need some tips. Thanks


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## imjustjason

I piece of poster board, a pair of scissors and a LOT of cutting and fitting.


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## jf2oo6

awash242 said:


> This is a basic question, but how do you guys get the measurements of the contours so well? I want to do something similar and need some tips. Thanks


My car had a trunk mat in it from the factory. So it followed the lines of the trunk exactly. If you have something like that I think it would be the easiest and probably the best way. If you dont have a mat maybe try to remove the carpet down there and use that? It all depends on what you have in your trunk. But if not poster board will also work. Just keep cutting and trimming until your happy.

Measure twice cut once!


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## Lanson

This looks really good. A few things I've learned along the way of doing several false floors:

Light, strong wood beats MDF every single time. MDF's major advantage is when you need to sand curves and make baffles with a circle-cutting jig, etc. When it comes to false floors, none of this applies typically so take advantage of the stiffer, lighter materials out there. Sometimes cheaper, too. A slightly warped piece of plywood will straighten up really quick with a few support beams underneath.

The other thing is that carpet, factory carpet mats, even those with heavy rubber backing, have virtually NO effect on a subwoofer's output. I was shocked with this ,but I've proven it with my own work several times. Even wood doesn't really stop the sub output. 

Here's a shot of my last false floor build:

































So hope that helps.


Oh yes, forgot to mention, my idol for false-floor and stealth construction is Bing. I recommend you look at every build he's done for inspiration of your own.


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## blindbug

awash242 said:


> This is a basic question, but how do you guys get the measurements of the contours so well? I want to do something similar and need some tips. Thanks


I've seen a lot of people mention cardboard, and while it is great to start with, I always have trouble getting the curves to be just right. I came across this post on another forum which mentions gluing playing cards along your edges to match the curves pretty tightly. I think it looks like a simple approach that would work pretty good... especially since I have like 10 decks of playing cards, a few of which I could easily sacrifice to the audio gods. I haven't had a chance to try it, but I think it looks like a good solution.




fourthmeal said:


> Oh yes, forgot to mention, my idol for false-floor and stealth construction is Bing. I recommend you look at every build he's done for inspiration of your own.


For sure. Bing is definitely on the top of my list of favorite installers, period. I simply love every single one of his installs! I see a little bit of homage in your install to Bing's work... in other words, I like it! :laugh:


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## Lanson

Thanks!

I also read somewhere you can use Popsicle sticks. They are dirt-cheap, and you just spray some Super-77 on a cardboard..and stick them one after another side by side.

I use welding wire, bend it to the shape, and then transfer that. Works ok for me. I also use a compass.


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## RBeachTL

http://www.diymobileaudio.com/forum...ow-make-trunk-panel-templates.html#post954505


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## 94VG30DE

I didn't think of welding wire, that's a good idea. I have tons of that laying around. By extension, I assume coat hangars might work in the same way (albeit not as well). Or any solid copper wire. I have a bunch of 12ga solid in-wall stuff laying around.


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## e36bumpin

jf2006, love how your trunk looks. So simple...


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## jf2oo6

Thank You sir. Clean and simple was the goal in mind.


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## GlasSman

ryan s said:


> Good PS skills
> 
> I would avoid MDF in the trunk and go with some plywood, preferably birch. MDF is like a sponge...even a bit of water will warp it..


You'd be surprised at how much water MDF can handle before swelling up.

I've had a 2' x 4" sheet sitting in a puddle over night and it didn't swell up a bit....._*I will admit*_ I was shocked.

I would recommend plywood over MDF in the trunk mainly because it's a more stable and lighter material...not because of the moisture issues.

If your trunk gets water logged you shouldn't have any 12v gear until it's properly repaired.


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## ryan s

The MDF I installed in my trunk last June is warped already...

Part of that is due to the amount of water I get in my trunk :laugh: It only comes in on the sides, so the jack handle things and the Jack Daniels tray get wet but NOT where I had the MDF. I'm working on it...


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## Vital

blindbug - any updates on this???


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## Commissionmip

I love the Photo Shop skills. I'm looking for some pics for a 07 Grand Prix.


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## Resonant

This thread has helped on planning my false floor thanks!


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