Faux Stucco/Plaster?

[aeneas1]

for indoor applications wouldn't a faux stucco/plaster product applied directly to the concrete board be an easier and equally viably option to traditional stucco? after doing an extensive net search for stucco products and the three-steps involved (scratch, brown, finish) it struck me that this was primarily for outdoor construction applications and not necessary if the oven would be indoors. compared to true stucco, faux stucco/plaster seems to be a breeze to use/apply - a single coat that can be applied directly to the concrete substrate.

am i way off base here? your thoughts would be very much appreciated....

[james]

I'm not a mason, so I'm hoping others will respond.

I have one experience with putting a pre-mixed finish stucco (STO) directly over concrete board, and when it dried, all the seams showed through. If you want to go that way, it would be better to make sure the enclosure was nice and smooth.

Still, if you use a traditional dry-mix finish stucco, that might have enough texture and weight to cover with one coat. Worst case is that you do what the drywall plaster guys do (gypsum that it) and use one coat to make all your joints smooth, then a top finish coat.
James

[CanuckJim]

Plaster

Aneas, James,

I have a fair bit of experience recreating "antique" plaster. First, apply 2x4 sheets of gypsumn lathe board. Second, apply a scratch coat of perlite mix, fairly sloppy, to get flat. Third, cook a mixture of lime and water overnight in a garbage can for a finish coat. Trowel on, then sand after a week. Do not paint for two weeks, at least. Three to four better.

Jim

[james]

This sounds pretty cool

Jim,
Can you go into more detail on this. It sounds like something that other might want to do. It's on the other end of the spectrum from a modern, one-shot color-in, pre-mixed stucco, but the finish sounds like it will completely different -- specifically for someone trying to match, or be compatible with nearby old-fashioned buildings, or looking for an old-world look.

What is 2x4 gypsum lathe? Is that similar to gypsum dry wall? Is there a green verison for using with water?

How does a perlite mixture work? Does it stick and can you get it smooth enough?

Etc, etc. I'm confused. Sorry.
James

[CanuckJim]

Plaster

James,

I got into this years ago when trying to match the look of the old plaster in my 1856 house. The board I mentioned is called Lathe Board. Don't know quite why it comes in only the one size: 2x4'. I've never heard of a green version for water resistance, but, then again, the board is made with a paper coating meant to absorb water out of the perlite mix (so it sticks). This stuff comes in 10 or so kilo bags. Here, it's called perlite base coat, meant for plastering. The roughness, or smoothness, of the base coat is adjusted by how hyrated it is. It really, really sticks to the board. I've used it on it's own for a really rustic look. For more "formal" parts of the house I top coated it with the lime water mix I mentioned, but you do have to cook it overnight (just let it stand in a galvanized trash can; it does get quite warm), and hydrating it properly takes practice. Overall, trowelled out "smooth" it approximates the look of old plaster. You'll need a rectangular concrete smoothing trowel for this.

Jim

[james]

It sounds great. I hope somebody tries it one of these days -- I would like to see the process, and how it comes out.
James

[aeneas1]

james:

thank you very much for the above information - unfortunately the process you described is exactly what i want to find an alternative to. as i mentioned in my first post it struck me that such processes were intended more for exterior applications; exterior applications requiring insulation, weatherproofing, exposure durability, etc... and in the case of outdoor woodfire ovens, additional thermal mass.

but for an indoor oven that will a) not be exposed to outdoor elements and b) will already have the thermal mass in place behind the concrete boards, i wonder why one would consider traditional stucco and its added weight.

i came across a restaurant that had incredible looking interior stucco work but, upon closer examination, the feel was more like the material used for modern casts (as opposed to the old plaster casts - for bone breaks). the stuff was hard as a rock, didn't flake or chip (couldn't scratch it), appeared to be very lightweight and accepted paint beautifully. yet it still had all of the uneven, rustic, different-depth texture of stucco. i have contacted the builder and am waiting for a response - however the owner told me that he was sure that the stucco peices were not molded and then installed; that he saw the builders actually applying it with a trowel. any idea what this stuff could be?

[jengineer]

Ok so you are looking to apply some form of plaster directly to the concrete board. I don't think anyone has done that yet. I live in Los Angeles and if you are in the area i can let you have 3/4 of a bag of what is called California One-Kote. I used this inside the house to replaster my ceiling.

Our ceiling had what is called either popcorn or cottage cheese on it. Most of it had been painted at one time and the previous owners were heavy smokers. So when it rained and the house got a bit humid you could smell the nicotine off-gassing. I ended up having to scrape that stuff off and having it carted to a hazardous waste roundup. The ceiling has lathe board that then had plaster applied to it. In places the plaster was scrapped off by the ovezelous cottage cheese remover. I used On-Kote to plaster over what was left of the ceiling. It has super fine sand in it and can be put down either smooth or with some raised shapeing. I tired to do it smooth and after finishing part of one room the wife came in and said "can you give it more character, you know ridges" Oh you mean get it up quick and don't look for perfection, thanks honey you just knocked of 2 days of plastering as now I can go quicker". I then applied a sealer, Kilz, and then put on a latex paint - bright white.

I think you could do a test run with a scrap of the concrete board and some appropriate plaster and see how it stands up. Experiment on a smaple before applying it to the actual structure.

patrick

[aeneas1]

Re: Faux Stucco/Plaster?

just an update -

i ended up mixing sand into joint compound and skip-trowled it directly to the concrete board - it dried beautifully and quickly and bonded very strongly to the board. i will post photos when i can. in short, for those looking for a very inexpensive and easy to apply stucco look, you might want to consider a joint compound / sand mixture - for interior applications, that is...

[Georgina Gibson]

Re: Faux Stucco/Plaster?

Hi Jim
I am interested in using a perlite plaster to finish my walls in a new construction rather than drywall as I like the more rustic look I think it will produce. Do you have any pictures of your finished job ? it sounds like you have done a lot of this. I have heard that you can use the plaster on regular sheetrock put up back to front and indented with a hammer to make a key. Does this sound like a feasible think to do to you? I have not had much luck looking on the web for a how to guide on this do you know of any good info sources? What kind of wall coverage do you get out of a 10 kilo bag ?
Thanks!
Georgina

[CanuckJim]

Re: Faux Stucco/Plaster?

Georgina,

I'll get back to you on your question. Been very busy with baking stuff.

Jim

[jengineer]

Re: Faux Stucco/Plaster?

Cross post from photo for Gerogina

I noted that Jim couldn't find this thread so he posted the picture...

Unfortunately, I've been unable to find the post asking for a picture of basic perlite plastering from a lady wanting to use it in her house interior. Here's a pic of the "rustic" look I used in part of my house. This is a two coat job: rough out, then top coat to, ahem, more or less smooth and up to grounds (light boxes, switches, etc.). To get a, more or less, smoother look, cooked lime and water would be used over this, but it would never be exactly smooth. You could use drywall as a base, rough side out, scored with a knife for grip.



a larger photo is found at this link
http://www.fornobravo.com/forum/phot...ndex.php?n=160

[CanuckJim]

Re: Faux Stucco/Plaster?

JE,

Thanks bloodhound. I could take more or different pics if required.

Jim