>
> I would appreciate any experience or advice you have about installing epoxy
> floors; I know almost nothing about them. Especially; how is the concrete
> prepped for the epoxy? And the epoxy laid? How are workers protected? Do
> the epoxy emissions disperse quickly? Any chance of them being absorbed by
> other building materials? What's the cure time? Ventilation
> recommendations? Are there epoxy materials you would recommend? Can color
> be incorporated? How is epoxy maintained after its cured? Are there
> chemicals that would damage it after it has cured? Are there any disposal
> issues around the epoxy containers?
>
> I couldn't think of any more benign concrete floor finishes or coverings
> that would stack up to the epoxy--if you know of others, I'd be interested.
I am a construction specifier for an architect, and have specified many
epoxy floors for labs.
Epoxy floors are very durable, and come in a very broad range of
products. They all use a 2-part chemically cured resin. The
manufacturer's will point out that since the products cure by the effect
of a catalyst, not solvent evaporation, they are essentially odorless.
This, of course, isn't completely true, but their VOC content is low
compared to say oil based paint. There are also products based on MMA
(methyl methacrylate) that have a very intense odor, though relatively
short lived. I am not sure what protections workers need for epoxy, but
since many labs are in confined spaces, probably carbon filter breathing
aparatus. But these systems cure in about 24 hours.
Epoxy floors are very sensitive to preparation. The best method is
shot-blasting or grinding with a terrazzo machine to remove all
contaminants and, if new concrete, laitance. If the slab is on grade it
must have a vapor retarder underneath (like most flooring, actually.)
To the epoxy is often added quartz aggregate that gives the floor
toughness against point and rolling loads (like lab equipment). There
are 2 primary ways they are applied: broadcast and trowel. Broadcast
systems have a layer of epoxy squeegeed onto the floor, then the
aggregate is broadcast, or sprinled, by hand into the epoxy to
completely cover it. This can be done in more than one coat. The
trowelled systems, which are harder when in place, have the aggergate
mixed with the epoxy and then trowelled in place.
The aggregates come in many colors and con look "tweedy" if desired. The
epoxy can also be pigmented in the less expensive systems. Over the top
of the cured epoxy various top coats are applied, typically epoxy
(without aggregate) to fill pores. For higher chemical resistance,
urethane coatings are sometimes used.
The tricky thing about a lab floor in terms of its greenness is that the
materials used in a lab are often inherently very un-green. The
protection of the user and of the space itself becomes pretty important.
Since these floors can be readily cleaned up and do not easily fail from
chemical spills, they are used in many, many labs.
However, for labs with run-of-the mill reagents and whatnot, it is not
true that vinyl will not work. Probably more labs are done with sheet
vinyl and VCT than epoxy, and at much less cost. It is important to know
exactly what chemicals you are trying to protect against and start
there.
If you have any more questions, I'd be happy to try to help.
John Bunzick, CCS, CCCA
HKT Architects, Inc. (formerly at Dean Packard Rafuse)
__________________________________________________________________
This greenbuilding dialogue is sponsored by Oikos (www.oikos.com)
and Environmental Building News (www.ebuild.com). For instructions
send e-mail to greenbuilding-request@crest.org.
__________________________________________________________________