Expert: Daniel Humphrey - 12/4/2008

Question
Hello,
We have recently renovated a barn into office space, and we poured a new
concrete slab over radiant heating. The space will be used for photo shoots
and will have a fair amount of traffic. I'd like to seal the floor with something
clear, durable, and low-voc. I'm not sure if I need a penetrating sealer or not,
and I'd really like to not have to repeatedly apply it over the years. Having it
not be stinky is also very important. Any ideas?

Thanks very much!
Sarah

Answer
Dear Sarah,

I know you're looking for something fairly inert to apply that will last a long time and keep the concrete surface from constantly dusting up. Those kind of products are waxes and oils and are re-applied frequently, such as every time you mop. I recommend the acrylic waxes if you are going that direction, but they are not permanent on a floor.

From personal experience, I recommend two products as permanent concrete sealers, but both of them put out a LOT of volitile organic compounds while curing, but very little after the brief curing period. The good news is that you have in-floor heat, which shortens the curing time and makes a better bond.

The very best sealer I have ever applied is Armorpoxy. This goes on like a self-leveling paint and hardens to an impervious, easy-to-clean substance that doesn't chip too easily when you drop a wrench or something. Because I have seen identical floor sealers of different brands, I've suspected that this product is manufactured by one company and sold under different names to contractors.You can stick tape to it and clean it with solvents, and it comes in a neutral gray and can be colored with color chips to make it look like terrazo or granite. I have used two kinds-- Armorpoxy and ArmorUltra. You can find the product description and the VOC data here:

http://armorpoxy.com/commercial6.html?gclid=CJObsobiqpcCFSIgDQodbgthjg

The other type of permanent concrete floor sealer I have been happy with is a two-part urethane floor varnish. I think a number of manufacturers make about the same urethane product. You can do a search and find someone near you that has good customer service and reviews.

Since your concrete is new, you must take special precautions that you apply the products only to cured (and possibly etched) surfaces.

Hope this helps.

Daniel