An Experimental Mess: DIY destroyed building debris for tabletop gaming.

As part of my Bolt Action / SPR building spree ( click for details) I had wanted to try a method for making a large volume of Destroyed Building Debris (DBD) cheaply and easily, and look ~ realistic at tabletop scale. Here are the results of that experiment, along with how to replicate it yourselves. 

The DBD would need to relate to the type of construction, in this case, brick or stone and wood. I didn't worry about plaster or furnishings. This is for gaming, not a competition diorama ;-).

I theorized that I could make a large volume of DBD by using patching plaster, colored with a latex paint, and cut into "bricks" while damp. Fortunately, I had a tub of joint compound lagering in the basement. You'll need that,  a cookie sheet that's no longer needed for food grade cooking, paint for color, a tool for smoothing and cutting  and shaping your mix.

 I took about a cup or two and added some brown latex house paint for color. It took rather more than I thought it would to get it brown enough.

Stir until smooth and the color is mixed enough to eliminate any white. Some variegation is not just allowable, it's desirable. Move your mess to the cookie sheet and spread to the desired shape and thickness 

The addition of the latex paint really slows your dry time, so I recommend popping in a 200-250 oven for as long as it takes to begin to firm up and leaves your knife/spatula/trowel dry when you cut it, but not so dry that you can't. You can then begin to score it into bricks/blocks to the desired size.

Once that's done, leave it until it's "baked" through. Once cool, scrape free and break into the desired bricks/blocks. Save everything, there should be lots of "fines" in your mix. If there's not, makes some by crushing some of your debris. A few tips for those who follow:

1. Make the sheet thinner, and your bricks smaller, then you think you'll need.

2. Try to get your square of plaster as even in thickness as possible, so that it dries at the same rate. 

3. It will dry from the outside in, so you'll need to do your scoring/cutting progressively, lest some parts         be too dry and the middle still soft.

4. Use the thinnest tool possible to score. I had a twelve inch putty knife, so I could score it all the way         across with one push.

5. I found that cutting each row in sequence caused problems, pushing the plaster out of the way rather     than cutting. To avoid this, imagine your final "Grid pattern", and cut every fourth. Let it cure some,         then cut half way between that. Wait again, and cut between those to your final dimensions. 

I also wanted to add some "lumber " to the mix, so I took some balsa cut in planks of the desired width, and broke them by hand into random lengths. These were thrown into the disposable plastic mixing bowl we used earlier, and added a wash of the same paint used to dye the plaster, thinned with water. Mix by hand until no raw balsa color remains. When dry, throw your lumber in with your bricks, and mix.

You could simply pour it out, and pick it up later, but I wanted it to stay put. I  attempted a spray of dilute white glue, which was completely ineffective. Plus, I wanted the piles to be thicker where the walls had been, and thinner in the middle. This is where patience, persistence, and a fast, clear drying white glue are necessary. Sort your debris into small (fines), medium, and large chunks.

Place a random appearing layer of large chunks along the lines where walls would have stood. You can even stack some into walls if desired. After dry, add more, and a sprinkle of fines. As you make your piles higher, add more medium and fines. Lumber can be random or joined into small panels, to eye. Do what looks good to you. 

Deeper piles along "foundation lines"

If I were doing this again, I'd make a few smaller batches and vary color in each, and stir them together. I'd also make them smaller and thinner, more to scale. Additionally,  I did the building separately, and the building colors and debris colors should be a better match, not an afterthought. I'd also like my lumber color to be more distinct.

If anyone else tries this, please share your results.  Overall I like the effect, it was very cheap, but not super fast. Good luck!