Ballistic protection for interior walls, ideas...


April 16, 2008, 06:47 AM
Sirs and Ma'ams,
I have an interior wall to which i would like to add a decent amount of ballistic protection. This layer of... whatever... will slip between an existing wall and a bookcase that i am installing. I am also asking for your help with a source for the material.

So the requirements are:

1. ballistic protection, higher the better but lets say no lower than equivalent to NIJ IIIa

2. thin enough to be hidden behind a bookcase , such that it doesn't look like 'Hey, cpileri has something behind that bookcase! See how far it sits from the wall..."

3. light enough to be supported by the floor of a 2-story home. The floor that will support it is the 2nd floor, or the 'ceiling' of the first floor- however you want to look at it. So I am thinking bulk steel plate is not an option, but I don't know. That's why i am asking.

It can be clear or opague, pretty or ugly; doesn't matter as it will be cut-to-fit and not visible when installed.

Also, I am not going to tear up my walls, so no offers to fill the insides of the wall with gravel or foam or whatever. Basically, I have a normal, plaster/wood/stucco/chickenwire home and I am putting in a bookcase that will sit up against the wall, and be bolted to the studs at the top to keep it from tipping. It will be filled with books. Books, OK, do provide some ballistic protection but i would like to add something behind the case, between it and the existing wall, as described.

I am looking for all knowledgeable advice on materials, suppliers, cost and weight; and anything I may not have looked into.

Thanks All, in advance for your time and expertise.


p.s. Yes, this is a serious question! :)

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Rabid Rabbit
April 16, 2008, 08:00 AM
1/2 inch AR400 - AR550 steel. A month ago a 4x4 sheet was $1,500 full sheet $2,000. This is the steel they use for knockdown targets and some armored cars.

April 16, 2008, 08:04 AM
sure you could..but why?

Stack / glue / nail old vest panels from police surplus to wall?

April 16, 2008, 08:10 AM
diamondback tactical and similiar companies sell balistic blankets. They work. Or you could look into sheets of kevlar. We used to cut them and fit them to humvees before we had armor kits...pretty expensive, not to mention a health hazard and hell on a circular saw. You have to change blades every five minutes and will probably burn the saw out before you finish.

April 16, 2008, 08:11 AM
how much are you looking to spend?

there are several compsites that would meet your needs, but your not going to like the price...

April 16, 2008, 08:33 AM
I appreciate the responses so far.

Steel: probably would weigh too much. 0.5" AR400-550 steel weighs in at ~20lbs/sq foot. So as an example of a 6' by 8' bookcase backing, would weigh 960 lbs and it would be standing on its half-inch edge; which is too much stress for the floor to take. I wouldn't want to damage the floors, and especially not have it fall on someone- example, a housefire and the fireman is crushed as it falls through the floor. I dont think i could get it up the stairs anyway.

Old vests: i was hoping for a more reliable source of kevlar if kevlar is the material chosen. I decided not to post a "please don't ask me why/ suffice it to say I am doing it" caveat on my original post. So here it is now.

Ballistic blankets: In my mind, I thought these would be the best solution unless bulk kevlar weave is available somewhere. So the blankets are still on the list of possibilities. Thanks for the Diamonback tactical source suggestion!

Spend? I dunno: 5 or 10 bucks. :) Kidding. I may have to adjust my spending limit when i see the actual cost of the project. Can you list any of the several compsites you mentioned? I can contact them and ask for quotes.

Thanks again! Please keep the suggestions coming.

April 16, 2008, 08:37 AM'sBallisticTest.htm,0&search_id=135524

April 16, 2008, 08:50 AM
I've not tried this, but somewhere I've read were someone mentioned recyling tires this way? Please do your homework before trying this...SINCE I'VE ONLY READ ABOUT THIS ONLINE SOMEWHERE.
BTW; Did I mention that I haven't try it ; -)

April 16, 2008, 09:00 AM
Well there are basicly 2 types:

resin impregnated fiber and laminated "arcylic"( often incorrectly called bullet resistant glass, same concept, diffrent materials.)

I have no idea on the cost of the 1st,but I do have lots of exp with the latter. UL 752 is pretty much the standard they all meet, which basicly means they are UV stable and can take 3 shots of 44 mag in I beleave a 6" circle Or 1 7.62 x 39( its been awhile). They are from 3/4"-1 1/4" thick and run anywhere from 1700-4000 per 4'x8' sheet.

Bud Tugly
April 16, 2008, 10:37 AM
Many high-end canoes and kayaks (in the $2000+ range) are made from kevlar cloth. Those boats are extremely light and designed to be nearly impervious to impacts with sharp rocks while running rivers.

I have no idea whether the fabric they use would stop a bullet, but I'd bet it at least slow it down significantly and be available in bulk rolls. You might want to inquire at places that sell or build canoes and kayaks to see if they know a source for the raw fabric.

April 16, 2008, 11:50 AM
Spall Liner

Jim Watson
April 16, 2008, 03:15 PM
An indoor range in this area uses 1/4" polycarbonate between sheets of plywood for overhead baffles to prevent shooting holes in the roof. Another used sheetmetal between sheets of plywood for the same purpose. It was pretty heavy gauge sheetmetal but way short of what you would consider armor plate. I don't know what they would do for a direct hit but it is something readily tested at no huge cost.

April 16, 2008, 03:17 PM
sand won't do? What exactly are you planning on doing?

April 16, 2008, 04:02 PM

What we do depends on structure.

Factors include, but not limited to: Firewalls, insulation ( some walls have interior insulation for sound proofing, and this can be fiberglass, or sheets of Styrofoam,), wiring, scalability for wiring or other needs in the future, direct ownership, rental, lease, environment (rural, semi rural, urban, office building, strip center, ...etc.

Methods employed also vary in considering finances.

1. Aquarium gravel and similar can be "inserted" from ceiling. Just "poured" if you will and it works it way down and around wiring, outlet boxes and the like.

2. Sheet of Plexiglas, to sandwich media, and a false drywall to cover.

This requires blending that false wall with existing structure.

Pop the baseboards, and molding at top of that wall, mount false wall, repaint, chair rail, wall paper, - whatever it takes to make it look as was, or need to be "interior decorating-wise".

Re-install baseboards, crown molding, and sometimes a "decorative" wood trim to run down from top-to-bottom on corner, and "decorative" corner protector on the edge if there is a door facing or entryway.

Note: Media can vary, something like old bricks works fine, and less monies

3. Looking at number 2, instead of Plexiglas use Decking (press-board) or plywood.

I actually like and suggest this method.

What I and mine do, is "build" this thing on the floor, then mount it.
We even make a old fashioned "blackboard" with wheels, to make portable.

Bricks (going from memory) are ~ 8x 2 1/4 x 3 1/2 ", we use the ones with holes.

We measure out and build "sections" of squares/rectangles to set these bricks into.
2 x 4 cut and screwed into wood, and screw head side goes to existing wall.

We take wooden dowels that fit into the holes in the brick, and cut these dowels to keep them lined up and straight, cut just below top and bottom of brick, we want these to stack.

Just pick up a "section" of brick, and set into "frame section" we are building.
Once filled, add plywood, then paneling, or thin plywood, then drywall.

We use small 1 ton, 1 1/2 ton hydraulic jacks, with 2x4s across to hoist up and hold, for some applications.

Now we do like the chalkboard idea, just now use eraser board.
For a kids room, one can have this, with practiced plans, and that kids knows to stay down behind that eraser board, even a "toy chest" that is not, instead also filled with media.

4. Bookcase, dressers, buffets and the like.
Instead of doing the wall, make wood to match the backside, and build a false back, akin to false wall.
Bricks can be either laid flat or sideways, depending on how thick and how far away from wall.
Sideways is what I did the last few times.

Just easier to remove bricks in moving, and then put back when moved to where it needs to be.

Just some of the ways this has been done.
For me- how raised, what you do.

We did not have some of the things back in the day we have now, and being honest, these old ways still work better IME/IMO than new ideas.
Especially for those on a budget.

If...If you can find a steal of a deal on a bullet resistant one-way mirror or glass, get it!

Glass bricks are coming back in style, and that has always been a best kept trick in bullet resistant barriers.

Ever notice how some bars have glass bricks, or some office settings and the small glass brick wall in the lobby where Information, Security, or Receptionist is.
It was not for decoration, it was "decorated" that way on purpose with cover in mind.


April 16, 2008, 04:22 PM
Be careful, such building material can not be to code and cause issues reselling a home if it becomes known, and liability concerns later if it becomes known and was not disclosed.

Hardened glass like materials do amazing things to bullets and are relatively inexpensive.
Two such materials seperated by a medium that slows and catches rounds can cost very little and stop most rounds.
You can buy such things intended for that purpose, though they tend to be expensive because they are a specialty item.
You can also build such things yourself for a mere fraction of the cost, and take some samples out someplace to shoot with various calibers(watch out for richochet potential.)

That is why automobile windshield glass is such a pain and easily deflects bullets and even when they do penetrate they lose a lot of thier energy, and it is thin and not even designed for that purpose.

The angle can also help. A bunch of intentional angles would take more material, but could essentialy form bullet traps and deflect most calibers in the desired direction. All concealed within the wall. It takes even less material strength to deflect a projectile than to stop it altogether. That is why most tank armor is sloped the way it is.

how much are you looking to spend?

there are several compsites that would meet your needs, but your not going to like the price...Most expensive protection is expensive because it is designed to offer protection and be light weight for the level of protection for either an individual or something mobile like a vehicle that only has so much horsepower. When weight is not a concern it can become quite cheap to provide the same or better protection.

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