Deliberate stains or colors & finishes can be applied to concrete floor slabs, countertops, tables, or other concrete surfaces as a finish treatment using acid treatments or paint-on stain colours.
At left we see brown rectangular stains that are an artifact of a previously-installed vinyl asbestos or asphalt asbestos tile floor that has been removed, the surface cleaned, polished, and then sealed.
Color and finish methods for concrete surfaces include at least the following approaches.
Clean & polish raw concrete or old concrete from which other flooring has been removed. Unless a clear top sealant is applied, normal concrete will not usually polish up to a glossy surface but the finish may be adequate for many applications.
Polish new concrete formulated to accept a gloss finish by using necessary concrete additives or formulation but without application of a colorizing or staining agent.
At below left the variations in gray color of the interior hard-finished floor are within normal occurrence on a hard-finished concrete floor slab of this Tivoli, New York home.
At above right is a much more rough concrete surface with voids caused by air entrainment. This concrete,discussed at CONCRETE STAINS, would not take a high gloss polish.
Polishing a new concrete mix formulated to accept a gloss finish, typically by adding marble dust, and that may have deliberate inclusions such as pebbles, stone, or even glass fragments. Below are two concrete-cast tables whose finish surface used this technique. The same method may be used on interior or exterior floors.
The addition of marble dust to the concrete permits polishing to a hard glossy finish such as the concrete table shown at below left. A second polished concrete table constructed by the same owners and workers is shown at below right where glass inclusions from bottle fragments form a dramatic but smooth-surface.
Here is a CLOSE-UP of the polished edge of this table whose composition includes concrete, marble dust and bottle glass inclusions. - Thanks to DP & LM in Guanajuato.
In some approaches a layer of formulated concrete (with marble dust for example) may be poured atop a thicker layer of standard concrete mix before the first pour has fully set and cured. The top layer permits the desired polishing while the standard concrete mix used for most of the thickness reduces the installation cost.
Colored finish surfaces on concrete floors are applied using one of these methods:
Concrete dyes: a coloring agent penetrates the concrete using an ultra-fine coloring agent that penetrates the concrete leaving less surface residue than some other methods. Dyes are permanent (and so will be almost impossible to remove) and are sold in water soluble as well as solvent-based formulas.
Shown above and below are sections of colored concrete flooring in the Hacienda Las Trancas, Dolores Hidalgo, Guanajuato, Mexico. This floor was constructed in 1932 and remains in superb condition (like the author) for its age.
Concrete stains: usually an concrete coloring process that uses an acid-based coloring agent that works by chemical reaction with the CaOH (Calcium hydroxide) in the concrete. Using an acid stain to add color to concrete can give any of several color ranges such as the examples shown here.
Concrete paints: paints (including epoxy paints) formulated to bond well with concrete surfaces, imparting a hard traffic-resistant surface.
Surface polishing: concrete may also be left in its natural color and color variations, polished to a hard finish, possibly coated with a clear sealant with no coloring agents applied.
Concrete sealers: indoor concrete floors as well as outdoor concrete floors that have been stained or colored are usually protected using one of several sealants.
Indoor concrete surface sealants include
Epoxy sealants or coatings
Urethane sealants or coatings
Exterior concrete surface sealants include
Acrylic sealants (recommended as they don't trap moisture below the coating), requires re-coating periodically, as often as every two years
Watch out: be sure to consult your concrete coloring agent, stain, or dye manufacturer to assure that the sealant you select is recommended as compatible with the concrete coloring agent you used. Also be sure the surface has adequately cured, dried, and has been cleaned before applying any stain or sealant product.
Watch out: several sources we reviewed including attributed to SolCrete (below) warn that rubber-backed carpet padding or throw rugs may trap moisture, leaving a white stain on the sealed floor.
Failures & Disappointments in Concrete Stain Finishes
Below the concrete floor was "stained" using an acid treatment. The light patches in the left of the photo indicate foot-traffic wear through the acid-treated concrete surface . (Rigby 2006).
Wear on a stained concrete floor will be increased by any of the following
Foot traffic, especially if there is grit tracked onto or present on the stained concrete floor surface
Wear caused by hard wheels on office chairs, library carts, trolleys, or other rolling equipment
Moisture penetrating the concrete floor from below
Moisture left atop the sealed floor
Spills of solvents or acids that damage the protective coating
Poor original concrete mix or placement or excessive water in the pour that yields a soft, spalling surface
Irregularities in the concrete surface. For example if a walked-on concrete floor surface was not smooth, if raised surface areas were left as ridges or elevated particles, the added abrasion on those surfaces is likely to wear off or through the acid washed or painted-on concrete surface leaving surrounding areas intact.
Poor surface cleaning and preparation before the concrete was treated.
White Bloom On or Under Finished Concrete Surfaces
White blooming under a clear or coloured finish on a concrete surface may be caused by application of the clear coat over moisture or by the movement of moisture through the concrete from an outside water source such as groundwater under a floor slab or from plumbing leaks.
See these diagnostic articles on mineral efflorescence that can ultimately show up on finished concrete surfaces as white discoloration below a clear or translucent coating or that may appear as a crystalline or powdery deposit on the concrete surface.
Behr Concrete Stains, Website: http://www.behr.com, Tel: USA: 800-854-0133 Ext 2; Tel Canada: 1-800-661-1591
Behr's concrete stains & dyes include solid color concrete stains, semi-transparent concrete stains, and a decorative concrete dye as well as floor sealer products.
Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Ask a Question or Search InspectApedia
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Baragary, Chance, and Hani A. Salim. "Effects of cold joints in blast resistant structural concrete [abstract]." In 2007 Undergraduate Research and Creative Achievements Forum (MU). University of Missouri--Columbia. Office of Undergraduate Research, 2007.
Biel, Timothy D., and Hosin Lee. "Performance study of portland cement concrete pavement joint sealants." Journal of transportation engineering 123, no. 5 (1997): 398-404.
Bussell, M. N., and R. Cather. Design and construction of joints in concrete structures. Vol. 146. Thomas Telford, 1995.
Collepardi, M., R. Khurana, and M. Valente. "Construction of a dry dock using tremie superplasticized concrete." ACI Special Publication 119 (1989).
Den Entwurf, Neue Deutsche Richtlinie Für, Zur Rückhaltung Von Wassergefährdenden Von Betonbauten, Nouvelle Directive Allemande Sur La Conception, R. E. T. E. N. T. I. O. N. De Produits, And Dangereux Pour L'eau. "New German Guideline For Design Of Concrete Structures For The Containment Of Hazardous Materials." Otto-graf-journal 17 (2006): 9.
Erickson, Scott. "Pervious concrete durability testing." In Proceedings of the 2006 Concrete Technology Forum. 2006.
Fowler, T. J. "Lessons Learned from Refractory Concrete Failures." ACI Special Publication 57 (1978).
McCurrich, L. H., and N. R. Cook. "Airfield and road pavement use in the UK of high performance coal tar pitch PVC joint sealants, and a comparison of UK and ASTM standards." ACI Special Publication 70 (1981).
Odum-Ewuakye, Brigitte, and Nii Attoh-Okine. "Sealing system selection for jointed concrete pavements–a review." Construction and Building Materials 20, no. 8 (2006): 591-602.
Ribeiro, AC Bettencourt, J. Díez-Cascón, and A. F. Gonçalves. "Roller compacted concrete-tensile strength of horizontal joints." Materials and Structures 34, no. 7 (2001): 413-417.
Sarsam, K. F., and M. E. Phipps. "The shear design of in situ reinforced concrete beam–column joints subjected to monotonic loading." Magazine of Concrete Research 37, no. 130 (1985): 16-28.
Soliman, Haithem, Ahmed Shalaby, and Leonnie Kavanagh. "Performance evaluation of joint and crack sealants in cold climates using DSR and BBR tests." Journal of Materials in Civil Engineering 20, no. 7 (2008): 470-477.
Yan, Shangyao, and Weishen Lai. "An optimal scheduling model for ready mixed concrete supply with overtime considerations." Automation in Construction 16, no. 6 (2007): 734-744.
Yildirim, Yetkin, Yusuf Yurttas, and Ilker Boz. "Service Life of Crack Sealants." In First International Conference on Pavement Preservation. 2010.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: firstname.lastname@example.org. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones