Stucco help

[PizzaJNKY]

The finish line is in sight, but I don't quite understand how to stucco. I want to finish my oven by stuccoing the block stand, then paint it.

I've heard that I am supposed to first apply a scratch coat (Not sure what it means), and I've also heard that I should first apply chicken wire. (I'm confused), I don't even know what to buy at the home depot to get started.

If anyone has already done this type of work, and can either tell me what to buy, correct steps to take, or even tell me of a previous thread that discusses this part of the job, I would be forever greatful.

Thanks again.

[egalecki]

Re: Stucco help

this is my understanding- which may be wrong.

A scratch coat is a rough (not really really rough, just not plaster-smooth) coat of mortar, which is put on either the concrete block directly, or applied over an expanded mesh. I don't think you have to use the mesh on the block itself, but you'll have to use either the mesh or chicken wire over the insulation on the dome. Although, if you've used vermicrete, you might not have to. Someone else can maybe answer that.

I've not done stucco yet either- but I did use cultured stone on a fireplace a few years ago, and we put roofing felt up first over the mortar board, then we put up the mesh, and then we used a scratch coat- it gave the stones and their mortar something "toothy" to grab. Seemed like overkill at the time, but it's all still standing, so it's all good to me!

I've seen the expanded mesh and stucco products at the Lowe's here- it should be down by the concrete stuff.

[gjbingham]

Re: Stucco help

Elizabeth has it correct. Roughly a half-an-inch of base coat (scratch coat) to get your general shape, though you can probably go thicker without consequence.

At home depot, check for poulty fencing. Hexagonal wire mesh. 15 bucks should get you a 50 foot X 24 inch lenght that is easiest to work with, at least in my hands.

[PizzaJNKY]

Re: Stucco help

Thanks for the info! Hopefully this weekend, I can get started. I want to try to summarize to make sure I understood correctly..

First, I apply mortar to the block wall, this is the scratch coat.

Second, once scratch coat is dry, I can then apply a coat of stucco. I am assuming that I can mix stucco in my wheel barrel, just like concrete/mortar.

Then I just paint it. If those are the only three things I need to do, then this part of the job should be a piece of cake!

[RTflorida]

Re: Stucco help

OK, I'm not a stucco contractor but I do live in a stucco home in FL where 90% of the homes built in the last 20 yrs. are stucco...so here are my two cents:
The dome - YES, some sort or wire lathe (or chicken wire) is needed over the blanket; then either vermiculete or perlcrete if you only used one layer of blanket, if you doubled or tripled the blanket (at least 3") you can move straight to the stucco - first a "brown" scratch coat, then the finish coat. Home Depot and Lowes down here also sell "all in one" stucco, which lets you get by with one coat - not bad stuff, but the old fashioned 2 coat method is prefered by the pros.
The stand - Wire lathe is not needed over concrete block in normal construction, again nearly every new home (incuding mine) down here is concrete block with stucco; the 2 coat method is applied directly over the block. In general construction, wire lathe is only used to cover a wood substraight such as OSB or plywood used over woodframed walls such as around bay windows and gable ends. In this application true wire lathe is used (medium guage wire sheets with a small - maybe 1/4" diamond pattern) - pretty heavy stuff; keep in my for home construction they are applying it to a flat wall and don't have to form it much. For an oven dome, chicken wire is prefered because it is easy to form to the curves of the dome. Hope this helps...its all I know, and the only actual stucco work I've done is repairing a few cracks on my house and applying a type N mortar base over my blanket/chicken wire/perlcrete before applying the mosaic tile to my dome.

RT

[Modthyrth]

Re: Stucco help

There are many different styles of stucco application, and it seems mostly to be trowel technique. I haven't tried it myself yet, but I watched closely and asked many questions when we had workers build a courtyard wall and fire pit at our old house. I have some reasonable pictures and can describe how the light lace finish was created:

A Sampling of Stucco Styles Available from Creative Stucco

Still, I'm going to be practicing on the backside of my structures before I get anywhere close to where people will actually see my work. It really looked like something that was mostly practice, like icing a cake. Still haven't completely mastered that one yet. ;-)

Nikki

[david s]

Re: Stucco help

Each subsequent layer should be a little weaker. That is, more lime and sand, less portland cement. Not sure exactly why, but that's what the cement supplier's recommendations are to minimise cracking I presume.