If you have "no place to go," come here!


People have used marble chips, seashells, glass, and even porcelain from busted up toilets to create terrazzo. Basically, a cementious layer (concrete, lime-based, or now epoxy-based) is skimmed over a base, and then the aggregate is either tossed in or placed by hand and trowelled in. Then you grind.

I want to put some terrazzo in the entryway and the mud room. We stuck some plywood in the slab so I’d have a bit of depth to work with. I’ll be taping off the mudroom floor to define the area I’ll be working, but I think I’ll do the entire entryway floor. So yesterday I set up a test. I had two questions: 1) if I put down a color coat, how would it affect the final finish and 2) how will my grinding technique affect the glass---will the glass snap off, fly across space, and embed itself in my eye?

I built a little form for a 12”x12” concrete paver (the kind you can get for a buck at the local hardware store).


Then I splatted on a blue color coat. I’m not using a blue for the terrazzo I have planned, but I wanted to see what it could do. I love this color blue as a pigment---it’s so saturated and deep---but the minute I add it to anything, it just gets weak and lame and sad. But I love cobalt blue glass.

I then placed some blue glass blue glass from a wine bottle I smashed, and then chucked the bits into a rock tumbler to get rid of the sharp edges.


Then I layers on a finer cementious layer and messed with it a little, and let it cure overnight. If you don’t use a trowel, it’s more like frosting a cake than plastering.


The next morning, I knocked off the form and set the paver on a piece of plywood. I have two grinders set up for use. The first is a cheapie with a concrete 25-grit grinding wheel on it, while the second is also a cheapie but not as cheap as the first. I modified a hook and loop wheel so I can just slap the diamond pads on as I go.

Workspace #2

Oh, that’s the front of the new house and our evil ladder.

I use the 25-grit grinding wheel for concrete for a first pass, and then successively use diamond pads at 50, 100, 200, 400, 800, 1000, 1500, and 3000 grits. Concrete won’t do much more after 800 grit, but I use two overlays (the last coat finer than the other) to get a certain finish quality, so that micro-finish and the glass in these pictures are ground to 3000-grit. If I were doing stone, I’d probably take it 5000 or 6000 depending, but 3000 is fine for this. With diamond pads, it’s best to go slower than you would think. The adhesives used to keep the diamonds attached to the pad will overheat and fail a lot sooner and these babies cost some money.


Terrazzo was traditionally created with a lime-based plaster. I could test one---I have five-gallon buckets of aged lime putty to experiment with. This material is from Niagara, a plaster manufacturer that specializes in making materials for historic buildings. I talked with a guy there who was clearly a savant in all things plaster. He could just rattle off this stuff about different plaster mixes on all these structures all over the world, and he’d done extensive research on lime and straw building techniques.

Lime is born angry. Remember at the end of the movie, “Amadeus,” when they chuck Mozart’s body in the common grave and then throw the white stuff on him? The white stuff was quicklime. It is highly caustic. Lime putty is made by mixing lime putty and water and letting it bubble and steam and hiss at you. I didn’t mix it---I mean, seriously, that stuff will burn you to the bone. In England, though, some people have small lime pits in the garden as a supply for limewash, because limewashing is still used on some structures. They’ll also use bags of lime on roadways that are being built. I watched a guy drop and rake several bags of the stuff. I got off my motorcycle, walked over to him, and asked him why he was doing that. “To stabilize the ground, love.”

I got this lime putty from a guy was going to throw away. He had half a fifty-five gallon drum of it leftover from when his daughter had plastered a garden wall. She had done a Venetian style of plastering and like a lot of Venetian plaster jobs, it required a buttload of burnishing, “burnishing” being another word for rubbing the surface until it’s hard and shiny. You can burnish with a trowel, a piece of leather, or even the plastic lids of cottage cheese containers.

I may or may not add a lime plaster coat to an interior wall. We definitely will be clay plastering the living room walls in a color the fab GF describes as cantaloupe. It isn’t really cantaloupe colored, but she admits that she related colors to food. This tickles me to know end, I must admit. Clay plaster is easy to work and takes a long time to dry, so I’m feeling pretty good about our chances of getting a good finish.

We’ll be limewashing the exterior of our house white every couple of years. Stucco cracks. The challenge is to find a way to seal the cracks that doesn’t mess up the wall. A lot of people use caulking, but damn, it’s ugly. A limewash is essentially the water sitting on top of lime putty, kind of a watery milk thinness and color. Limewashes turn back into limestone when they dry. But you have to roll on, like, ten coats to get a good limewash, which means a kegger to get enough people to help, and lime will, as I said, burn you.

When I cleaned out the fifty-five gallon drum, I ended up chucking the hand spade I was using aside and just grabbing it with my gloved hands. My skin got a little damp, but I didn’t think much about it until I dried off. The top layer of my skin sloughed off. Like a sunburn only I hadn’t gotten sunburned, and it came off in little pieces. Kinda gross.

Kinda gross, but in a different way was the dirty gray showing up in the white.


A chunk of lampblack mixed with machine oil fell out of the grinder and I ran right over it before I saw it. Ick.


All the grinders (I have half a dozen or so) will have to be taken apart and thoroughly cleaned before I do the other terrazzo. And I’ll need another set of diamond grinding pads, maybe I’ll wet grind if I’m inside. Grinding creates a lot of dust---I wear high-impact plastic eye goggles, a respirator, and ear protection when I’m grinding. Yes, quite attractive in that take-me-now sort of way.

I’m thinking the finished terrazzo will have a lot of small pieces of cobalt glass with either a bright yellow or deep orange background. The fab GF thinks the test is pretty. “It looks like a bowling ball.”

God, I love her.

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Submitted by hipparchia on

this is way cool. you will give us more photos as the project goes along, won't you?

chicago dyke's picture
Submitted by chicago dyke on

nice job! is anyone else helping you? i'm seriously impressed by your efforts.

i did massive amounts of tiling this past winter. small, decorative tiles i made from a whole mess of materials, which i later put in the garden paths to prevent overgrowth in key areas. i really got a taste for it and i'm jonesing to have some time to get back to it, and do bigger projects- this winter i'm going to try to make a table, and cover some larger surfaces with 'mosaics.' nothing so elegant and complicated as what you're doing, but it taught me a simple lesson about using cheap "junk" to make unique beauty. some of the materials i used as "tiles" included broken beer bottles, rocks and stones dipped in watered down colored paint, glass beads from the knick-knack store (much cheaper than glass tiles at the craft store), broken/trashed dishware and glassware from a dumpster diving expitdition, plastic buttons (again, tres cheap), shiny shiny from costume jewelry taken apart, twigs dipped in polyurethane, broken pieces of's hard to remember everything i experiemented with. anyway, the point i'm making is that you're doing a fuckload of work and i utterly respect that. but for the surfaces in my home that i want to do myself, and brag upon, i'll be using tile, rather than the sort of complicated process you seem to be doing. i'm lazy like that, but i appreciate the effect, and low cost, of making art on your walls and floors and various surfaces with little colored pieces of broken junk.

very nice work, thanks so much for sharing. i'm out in the gardens today, and if i have a second, i'll try to come back and drop a photo of some of my work.

Submitted by ohio on

Thanks for reading. I took these photos with the fab GF's PalmPilot and the colors are all wrong. We have tons of pix, but I prefer to shoot on film. Ah, the irony. I'll be getting an el cheapo camera probably today, one I can just carry with me and not worry about when I drop it.

But I love tile, too. We have tile going above the windows and door on the exteriors, cedar trim on the other three sides. Recycled green glass tile on the kitchen windowsills (from Bedrock Industries, probably the Water Stone green). I'd like some subway tile in the bathrooms interspersed with some mosaics I'll make with a mosaic frame.

The floor beneath the cupola has no slab and it will be flagstone. Last summer, I met this young guy with his own stone fab business. I went to talk to him about slate and stuff, and noticed this great freeform flagstone floor in his office. I asked him how hard it was to do, and when he realized I was thinking about doing that he blurted out, "Well, ferchristsake, don't buy any stone, just get it from my dumpster. Buy a stone hammer, chip the pieces to shape, lay them down on a level base, then grout. Geez, what are you, stupid?" My response, "Well, obviously."

It was pretty funny. Every Friday for months, the fab GF and I would get tacos from the taco truck, and then dumpster dive. We now have stacks of stone for the flagstone floor and to cut for vertical tile at the base of our bale walls. All of our friends made fun of our romanctic weekends, but you know, it was and still is a blast. It's interesting, too, to see what kind of stone these guys work with and how stuff goes wrong and in the piece goes.

Nice guys at that shop, too. If we decide to have any stone fabricated, they're getting our business.

But yes, it's a shitload of work. And either you love it or hate it. I move materials a lot and I hate it. But that's the price for the privilege, I reckon.

The grinding stuff takes time and some upper body strength, but it isn't really hard. Just keep the connection between the diamond pad and surface to be ground flat. If you want to try it, tell me and I'll send some grimy diamond pads and overlay (very easy to work with---just mix with water). I rescued a guy's concrete countertop with this stuff.

Okay, I'm going to brag. The reason I had the lampblack stuck in the grinder is that Dave, this friend of a friend, had done a cast-in-place kitchen island countertop that didn't quite turn out the way he thought it would. The form work was perfect (3'x7'x3", all curves, nicely done), but the concrete hadn't set up properly---it looked like gray oatmeal. So we tented off his kitchen and I ground off the worst of it and troweled two coats, tinted with the lampblack. Dave wanted a black countertop, but I suggested we go with a couple of dark grays and if he wanted it all black, I'd take care of it with the sealer I use.

Eight hours of grinding. I handcarved the 3" sides so they had this nice, fit-your-hand feel. It was MESSY, but it was beautiful. We ended up just sealing it clear because the varigations were dimensional. Yes, I'm proud of that one. I don't do this for a living, so I couldn't take his money, but Dave is a reknowned small-scale winemaker and I got a case and a half of his best red---a totally fair trade.

Seriously, if you want to try it, I'll lend you some stuff. You can get a little grinder for like, $10, from Harbor Freight or off ebay or your local craigslist.

Submitted by lambert on

See here.

[ ] Very tepidly voting for Obama [ ] ?????. [ ] Any mullah-sucking billionaire-teabagging torture-loving pus-encrusted spawn of Cthulhu, bless his (R) heart.

Submitted by ohio on

When you run your hand over it, it's all at the same level. I started with the glass being very scratched from the tumbling. When I was done, it was smooth and shiny again.

My blue glass will be much, much smaller and there will be a lot more of it. The design will be more something like this. I am no where near this skilled, but I sure like the shapes.

chicago dyke's picture
Submitted by chicago dyke on

it's not worth it's own pedantic and pathetic post; i'll just bask in your glory and try steal a little:



beer bottles and costume jewelry pieces

i'm much better with them now and plan on doing a whole floor, ancient mosaic style, this winter.

Submitted by ohio on

I see your naked toe.

I like the fishes best, I think because the less-vibrant colors, those blues and greens, remind me of the ancient mosaics and terrazzos like from Pompeii. Maybe it's the border. Maybe it's the all around balance. Maybe it's that it looks lived in.

Or maybe it's just the toe.

Doing a whole floor? Cool. Good to know I'm not the only insane one. I mean, creative and industrious one.

Submitted by lambert on

You can come beautify my area at any time.

[ ] Very tepidly voting for Obama [ ] ?????. [ ] Any mullah-sucking billionaire-teabagging torture-loving pus-encrusted spawn of Cthulhu, bless his (R) heart.

chicago dyke's picture
Submitted by chicago dyke on

and the fishies are 'muted' mainly because i didn't brush off all the dirt. oddly, the brighter the colors, the better they 'work' in the gardens. seriously. i was worried, in the dead of winter, that the tiles i'd made would be too garish and bright and clash with the flowers. no need for that worry, as it turned out that between dirt and the natural brilliance of the plants and flowers (no paint is as vibrant as Mo Nature's own paintbrush) one hardly even notices the tiles, until they have been stepped upon.

no, as for a floor....i assume you know all about the cost of materials, and likely what contractors charge to do the simplest of work. and i don't want yet another variation of some slave-made, environmentally incorrect, just like everyone else who shops at the bigbox store, sort of flooring in my bedroom. it'll take some effort, sure, but then again, what the fuck else do i have to do with long, dark, cold winter nights (other than snuggle with a honey, of course)? and i feel compelled, these days, to show that we waste *so much* useful material in our society, tossing aside colored glass and shiny objects just because they are 'dated' or 'used' or whatever else we convince ourselves makes them not worthy of reuse. anyway, i'll let you know how it goes. i'm waiting on the results of some legal action to begin the next big round of home improvement, so it may be the case that i don't get to the floor project until some far in the future time.

...i've got to be more careful about them toes, clearly. that's the second time a reader has made not of my utter contempt for shoes in the summer. ;-)

chicago dyke's picture
Submitted by chicago dyke on

now that i've got the hang of it, it's easy. they are working well separating my fleurs and keeping back weeds. you should have some too.

Submitted by lambert on

... doubling it, I'm going to need some sort of walkway or path, to run hoses over, and so forth. This kind of technology would be great for that.

[ ] Very tepidly voting for Obama [ ] ?????. [ ] Any mullah-sucking billionaire-teabagging torture-loving pus-encrusted spawn of Cthulhu, bless his (R) heart.

Submitted by ohio on

Rubble trench on the east end and standard stem wall on the west. Width was 22". Our site slopes too much to do an entire rubble trench. Rubble trench foudnations are old style, but work in this region just dandy.

First we dug the trenches 36" deep with a 4" wide drainpipe trench along the outside---dug by hand by someone not saying. The rubble trench was filled with...surprise! Rubble---rock without fines so any water could drain right through. Felt like I tamped every single rock. I used a Wacker gas-powered tamper, but a lot was done by hand.

The stem walls were formed and poured on a standard footing. Essentially, we poured parallel stem walls along the western perimeter and filled the gap between with...surprise! Rubble. I thought about putting in perlite, but didn't have time.

We then poured a 10" cap that tied the entire foundation together. A lot of concrete. And a lot of rigid insulation. And a lot of rebar, which is not hard to tie, but you do a lot of bending over. I tied rebard and worked during the pour. I also demo'ed the form boards and cleaned them, which is a really shitty job.

We then ran parellel 2x4 treated toe-ups running the entire foundation, locked down with Simpson TitenTM bolts that had to be drilled, and the screwed in with a rattle gun. We also used these bolts on some of our interior shear walls. Prior to putting down the toe ups, I kerfed 'em them every 2' or so to take hi-tensile strength wire to tie the top plate (that sits at the top of the bale wall) to the bottom plate---these toe-ups.

The key here is to make the entire assembly act as one when you're done putting it together. That's true of any structure---tie it from sky to ground so it can handle any forces working against it. I say "handle" rather than resist because while it may not be impossible to build a structure that can withstand everything, it is neither wise nor practical. In our case, our house is designed so if it should fail, it will fail gracefully.

For instance, in an earthquake. We're in seismic zone D2, not terrible, but still, you have to design for it. Our bale walls can handle a huge amount of energy, but the only part the engineering calculations are concerned with is the stucco. The stucco is doing the actual work, while the bales are considered insulation. (A self-styled bale expert once insisted it was the interior plaster stucco doing the bulk of the work, despite how counterintuitive this is. It may be true but I think he's full of crap for no other reason than he's an asshole.) Anyway, in the event of a catastrophic seismic event, the bales will act structurally so we can get out safely. And possibly even rebuild since stucco can be scraped off and put back on. Essentially, if the stucco buckles, the bales are heavy enough and wide enough that the roof can rest on them and the walls will remain standing.

Neat, huh?

What are the chances of such a seismic event? Slim. More likely major wind events (we designed for uplift and shear). Most likely damage to the structure is from water, so we have several fail-safes in place to allow us to stop if before it gets bad and if it does get bad, again we have a graceful failure and better chance at repair. Would SUCK to do, but I could do it. In the meantime, we maximized the thermal value of the assembly with high R-value bales and trying to build and keep an eye on proper detailing.

Anyway, the concrete cap that ties the foundation together sits about 6" off the finished floor interiorly, and 8" off grade exteriorly. So we have the bottoms of the bale walls away from any interior or exterior flooding. The slab interior is thermally decoupled from the exterior walls. Underneath all of the floor is at least 2" of rigid insulation, and pieces of 2" rigid on the perimeter of the slab where it meets and exterior wall. I even mitered the rigid insulation along the outside of the slab because I am crazy. And yes, I taped the edges and foam-filled any gaps because I am crazy.

I did the drawings and our neighbor did the engineering, which was handy because the inspectors at the local building department love him in a totally non-gay way. My neighbor is a weird religious DOMA guy, which is sad because he liked us despite his best efforts not to. His wife is a very nice gal, though, and while also weirdly religious, not as much of a bigot. They go on their lunch time walk, so I wave at them almost every day. Funny thing up here---people who don't like gay people mean other gay people, not us. We've had only one anti-gay weird thing happen in all the years we've been up here and that was during the cheesecake competition at the state fair. A bonnet-wearing gay hater judge would not stop staring at the fab GF and I. I mean, if the fab GF wasn't competing I would have caused a vaguely gay scene.

Geez,we have about five billion photos of every step of building this house. I should put them up.