Re: [GBlist] Confused about Stained Concrete

["Richard McCabe" <rmccabe@alumni.princeton.edu>]

Concrete is highly alkaline, but not toxic, though fly ash is another
matter.  The only outgassing is CO2, unless you use additives.  There is
some concern about Radon in aggregates, but is more of a problem in Europe
that the US.  You can limit any chance of Radon exposure by knowing your
sources.  In my case, only sand is used, not gravel, and I use about one
tenth as much aggregate and cement as conventional construction.

You can add color to concrete, but it is often added as a decorative layer
after the thicker slab has set, saving you money.

If it were me, I would use Dramix steel fibers and pour a one inch thick
floor (or 3/4"), including some color in it. (White portland cement gives
you more color choices.) The Dramix is used in place of any other
reinforcement, so this is easy, cheap and green, in that you are using so
little concrete. (Non-steel synthetic fibers are also available.) You can
even replace some of the portland cement with masons lime and make it
greener and ultimately stronger.  I would add a little microsilica/silica
fume (industrial by-product sold in a slurry) to make the finish
impermeable, and of course a water to cement ratio never exceeding 0.35.
Done in this fashion, you will never have cracking or leaks or any problems.
Do not paint it, as paint is completely unnecessary and requires maintenance
once you go down that road.  Either hire a final finisher when you pour the
slab (highly recommended) or practice troweling before hand.  Remember, if
you don't like the finish and color, you can reapply a paint thin layer of
latex and portland cement and coloring (metal oxides) with no sand, and just
paint it on to make a new color and finish. (Wire brush and wet the old
cement if it is more than a couple weeks old.)  An Acryl 60 and portland
cement mix will bond like crazy.  I recently did a half-inch thick curved
privacy wall around a spa that was a sandy beige.  After looking at it, we
"painted" it a green, darker than forest, to fit in better with the
surrounding redwoods.  Just as easily make it sky blue.  Or tape areas off
and create designs in different colors.

Stamp and stained concrete can be made to look like anything.  Check out
http://www.decorative-concrete.net/.  This can be done yourself, but it is
tricky.  The guys who get paid to do this charge insane rates.

Polishing the final finish is popular, but I like a smooth hard trowel
finish with an ever so light broom texture for non-skid, just not so rough
that it is unpleasant for bare feet and hard to sweep.

I also like a plain white mix.  The sand we get around here is slightly
yellowish, so you end up with a bright, slightly off-white finish...sort of
a Santa Fe look.  The bonus round is that it is very easy to light and
creates a very cheerful, bright space. You could probably add a touch of
brown and get a similar feel.

Whatever you do, measure exact proportions, especially if you are doing it
in batches and need to reproduce your color.  Be VERY careful with black. A
little goes too far.

I would be happy to give you exact mix specs on the thin ferrocement slab if
you are interested.

Richard

----- Original Message -----
From: "Donna Watkins" <donna@theherbsplace.com>
To: <b2@b2andco.com>; <greenbuilding@crest.org>
Sent: Tuesday, September 24, 2002 11:29 AM
Subject: Re: [GBlist] Confused about Stained Concrete


> I was told that concrete is a toxic substance.  One person I know has had
> her foundation poured and is leaving it sit for three years to "gas off."
>
> We're building with a basement and I would love to avoid all the cost of
> flooring down there for the rooms and thought of concrete but ruled it out
> because of having talked to this person.
>
> Can y'all enlighten me a bit!?  We're working on the flooring costs right
> now and trying to lighten the load, so this would be a great option.
>
> By stained concrete, does that mean, it is stained before pouring?  What
> about painting it with one of the good environ-friendly paints instead
since
> it would actually be the foundation slab which includes other areas that
> don't need to be decorative [workshop, garage, etc.]
>
> Blessings to you!
> Donna
> ---
> "The Herbs Place" for Adults, Children, and Pets
> Supplements, Herbs, Pet Foods, and More!
> http://www.theherbsplace.com
> <a href="http://www.theherbsplace.com";> </a>
>
>
> > From: "Bonnie Bruce" <b2@b2andco.com>
> > Reply-To: <b2@b2andco.com>
> > Date: Tue, 24 Sep 2002 10:01:18 -0700
> > To: greenbuilding@crest.org
> > Subject: [GBlist] Stained Concrete
> >
> > Cathy
> >
> > All the stained concrete I have specified has been for good size
commercial
> > projects.  I have always been pleased with the results.  If you are not
> > trying to achieve a perfectly even opaque finish (as with paint) you
will be
> > too.  It goes down well over new and old concrete with different
> > effects--but I like the marbled finish staining gives.  It is just about
the
> > most inexpensive finish you can apply to a floor and it demands very
little
> > maintenance.  L.M. Scoffield makes a good line of stains.
> >
> >
> > Bonnie Bruce, IIDA, USGBC, LEED Accredited Professional
> > B2 & Co.
> > Smart Sustainable Interior Design
> > 503.226.9489
> >
> > "..be the change you wish to see.."  M. Gandhi
> >
> >
> > ______________________________________________________________________
> > This greenbuilding dialogue is sponsored by REPP/CREST, creator of
> > Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
> > Environmental Building News and GreenSpec http://www.BuildingGreen.com
> > ______________________________________________________________________
> >
>
>
> ______________________________________________________________________
> This greenbuilding dialogue is sponsored by REPP/CREST, creator of
> Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
> Environmental Building News and GreenSpec http://www.BuildingGreen.com
> ______________________________________________________________________
>


______________________________________________________________________
This greenbuilding dialogue is sponsored by REPP/CREST, creator of
Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
Environmental Building News and GreenSpec http://www.BuildingGreen.com
______________________________________________________________________