ButterflyLion,

Can't say I've tried it, but I think it's an excellent idea. It's sure to look great, and the concrete blocks will prevent you from having to use too much tufa. Are you going for a faux rock look?

Amaretto, I haven't decided yet. I want something that will last and want something that looks different than the plain concrete blocks.

Well, that's a definite option.

If you go for it, give it a coat of a half inch or so thick.

It is quite durable, and, if you get a crack or something, you can always redress it.

I want to do a variation on that to make a sound barrier between my ac condenser and the house. Sound waves move our in straight lines and density of the barrier is key. So I'll fill the voids. It will be at least 4 courses tall, so I'm concerned the hypertufa might fall off. I hope someone with experience will address that issue.

I have 3 very different notions
1.attach some wires projecting out from between the concrete blocks and then put hardware cloth against the concrete. I'm sure the concrete needs to be wet when the hypertufa is applied.

2. Because it is a vertical surface, it might be best to use a different method: veneer the hypertufa on each block before building the wall.

3. Build the wall and "glue" a pre-made hypertufa veneer to each blcok.

HELP! I don't need a very heavy mistake in the yard.

Hey tufftufa-

Don't despair!

Your first option sounds much like the process that stucco application on a house would follow. You need to make sure that the wet mixture will bond to the cement block and since you can't staple the mesh to the block, I would wire it up as well as I could, make sure I had wetted down the blocks and applied a bonding agent, then slather on the mix like they do with houses.

Good Luck!

Jo

Tuffatufa

What kind of noise is your AC making? Different materials will absorb and reflect different frequencies.

If you have more of a humm noise, you might do better with wood.

If it's more of a hiss, you might do better with some kind of foam.

If it's a combination, create a wooden frame with your wall, pute some metal lathe on the side, fill it with different materials, such as foam, carpet, rocks, etc, then dress it with tufa for the appeal.

If you want to give it waves at the tufa application stage, to reflect different frequencies in different directions, you could us equally separated PVC pipes and dress the tufa over that.

Of course, you could also get a quieter AC.

Let me know how it goes :-)

Muddymesawoman & Amaretto, thanks. It's just general motor noise and an eyesore from the back porch. Why do you think wood might be better, Amaretto? Wood can act as a sounding board. From what I've read (and we all know how dangerous "a little knowledge" can be -I simply don't know) it is density that stops sound waves. If you have experience that may be much more valuable than my "knowledge".

What I'm thinking of is a 4-5' long wall, about 5 courses high and put a planter on top of that. (I've got to get out there and do some sight lines for placement and length.)

What concerns me is that the tufa will slump down the wall, but maybe multiple thin coats would work.

Replacing the condenser unit on a 4 year old house seems excessive. I've already moved it to the back fence, but that's only 8 feet back from the porch. (small l-shaped patio yard in a condo development. Entire patio is 24' wide and 22' deep. Porch on one side projecting 8' into the yard and 12' wide)

I'm paving much of the center and plan to have raised beds on the edges. (Nothing in the ground to bend over as I age, thanks.)

Tuffatuffa

AC noise has different frequencies. One of them being Humm, which typically transfers mechanically (making adjacent structures vibrate with them). Wood is typically used in combination with space, creating sound "traps" for lower frequencies (the humming part of your AC noise). Remember, higher frequencies have shorter wave lengths, so combining different density materials is what you're going for, unless there's a specific frequency range you want to address.

This seems like a good link. Let me know if it doesn't answer your questions and I'll do some more research

Bass trap

I think you're looking for acoustic insulation that wont look bad. Since AC noise will have a variation of frequencies, the more diverse materials you use, the more diverse the frequencies you will absorb. Then, the higher frequencies will just be reflected by the solid surface of the tufa.

So, this is how I would do it:

1) Make your wall with a frame of 2x4s for shape
2) Take a piece of plywood or something to go along the interior. Staple it 2 inches from the border (so you're in the middle of the wall).
3) Fill the remaining space (which should be about 2 inches on each side) with foam, carpet or whatever you can find and dispose of.
4) Use some kind of metal lathe to give the tufa something to cling to, and stable it to your wooden frame.
5) If you want to take it a step further, before covering with tuva, cut a few sections of PVC pipe and place it at even intervals accross the side of your wall (about an inch or two of separation). This will insure different frequencies are reflected in different directions
6) Cover the whole thing with tufa.

Then, cover with plastic so you can isolate the foam from your wet tufa when you apply

Now you have an effective bass(humm) trap, and high and mid frequency absorbtion and reflection (with the interior foam for absorbtion and the corrugated tufa surface for reflection)

If you can, lie your "wall" on the floor when applying the tufa. Or at least at an angle so our tufa doesn't slide down. You'll find this is where the lathe will come in handy ;-)

Forget my comment about replacing the AC. I have a noisy AC myself, so I am biased towards just dumping the thing :-)

OK, I'm typing a lot and I don't know if I'm answering your questions. Let me know if there's anything else I can do to help.

Tuffatufa

Woops!

I just got to actually reading all the posts. Yesterday I just browsed over it, saw acoustic insulation, and got a littls carried away there.

Seems you just want to use cement bricks with tufa. That should work just fine, and should be fairly easy. It would be less work too. So go for it!

The solution I presented is more suitable for audio freaks like me :-)

I saw were another gardenweb member used this technique for a 120 ft. retaining wall. (Scroll down to see the current link for pics.)

Here is a link that might be useful: Hyper Tufa Concrete Block Retaining Wall

Thanks amaretto and everyone. We're going to be traveling until early May, but when I do this I'll try to post pix from my new camera.

I've got time to rethink this, but the present plan is to do a dry stack concrete block wall on a 4" deep footer 12" wide. I'll put in some metal ties, pour mortar in the voids. When it all cures, cover it with hardware cloth held up by the ties. Then thin coats of hypertufa to build it up.

You know the famous saying: "Doctors bury their mistakes ...
architects plant vines."

I am wanting to do the exact same thing...make a raised garden bed with cinderblocks and then cover with something more appealing.

I've read about guy on the forums who makes veneers/face plates out of tufa. I guess you just make them the same size as your block and only 1 inch or so thick. Make a texture on the outer surface and then go back and attach each face/veneer to each block.

I'm currently considering this method. The advantages I see to this method are that I can keep the bricks all separate (no need to worry about cracking and movement). Also, with the bricks still separate, I am free to change things up a big without too much hassle.

You can make a mold with a nice texture on the outer surface.

Bobn4burton, I am working on different ideas (on paper for now) for using the blocks and plan on doing something when the weather gets a little warmer. How many places sell the concrete blocks? How much do they usually cost?

A new idea for my project. Comments, puhleez.

I'm concerned about attaching hypertufa to vertical concrete surface of my wall. Considering making some molds and curing them on the block directly. Would need to saturate the block with water in advance and keep all of it wet as it cures. Should I cover the block with a glue (like Elmer's) or anything?

Thanks, David

Hey tufftufa-

Veneers are all the rage these days. Go to a local company that applies those kinds of facades and find out what they use to stick the veneers on.

here are a few links to companies that do this kind of work to get you started...some pretty cool ideas.
http://www.sunset.com/sunset/Premium/Home/2004/03-Mar/StoneVeneer0304/StoneVeneer0304.html
http://www.bouldercreekstone.com/
http://www.virtualstone.com/
http://www.bobvila.com/BVTV/HomeAgain/Episode-1419.html
http://www.rvsproducts.com/

I am new to hypertufa, and it seems like the perfect thing for creating mod planters to go outside my mid-century modern house, but I love pebbles pressed into concrete. Does anyone have experience with this?

Thanks!