The Meadows at Martin Downs Homeowners Association, Inc.

2550 Waterfall Blvd., Palm City, FL 34990

 Phone: 772-283-2250      Fax:  772-283-9024

 

 

 

CONCRETE STAINING PROCEDURE

(Contributed by Walter Sokolowski)

INTRODUCTION

In Florida, unsealed concrete surfaces are difficult to keep clean, due to the warm, moist climate. However, if you wish to reduce maintenance and improve the appearance of a patio or driveway, sealing these concrete surfaces with a penetrating stain will do the trick. By applying a stain, the porous and abrasive surface of the concrete is inhibited from readily being discolored by mildew, rust, oil, grease or tire marking . Staining will not prevent most of these problems from occurring, but since they do not penetrate the concrete, it is much easier to clean such blemishes and mildew can almost be eliminated. Homeowners unwilling to undertake the procedure could contract with a Meadows registered painter or contractor.

This text is provided only as a guide and no warranty or liability is to be associated with the use of this information on behalf of the author or the Meadows Homeowners Association.

ARCHITECTURAL CHANGE APPLICATION

The Meadows Covenants require all homeowners to complete an for any alterations to the exterior of their home and submit it for approval to the Homeowner's Association. This includes staining of concrete surfaces. The only color approved for that purpose is the one specially formulated to closely match the color of natural concrete.

EQUIPMENT & SUPPLIES

The following equipment should be available:
- Solvent resistant roller with a phenolic core (minimizes the chance of roller will separation) i.e. Top Coater 1/2" or 3/4" pile.
- Extension handle for roller and a metal roller tray
- Metal bucket (2 gallon) to mix stain and solvent, and Rhino Hide for final coat
- Chemical resistant tank pressure sprayer
- Rubber boots, gloves and safety glasses
- Plastic garden sprinkling can (2 gallon)
- Short bristle push broom
- Pressure cleaner (desirable but not essential)

The following supplies may be required:
- Paint thinner, or commercial oil and grease remover
- Tri -Sodium Phosphate (TSP)
- Chlorine or household bleach
- Muriatic acid
- MAB Acrylic Silicone Concrete Stain (Xylene based) - Special Color 9-50 Meadows G - specially formulated for the Meadows - to closely match the color of natural concrete.
- Xylene solvent. .
- Rhino Hide (anti-slip) additive

SURFACE PREPARATION

If your concrete is stained with some but not all of the contaminants described in this text, treat only those which apply. However, at least a Muriatic Acid wash is mandatory. A cautionary note: it is much better to do more than is required, rather than less, since it is impossible to redo a prep stage that was overlooked. This could adversely affect the quality of the finished product.

Since all other cleaning procedures involve the use of water, it is essential that you tackle the removal of any oil or grease stains first. Although common mineral spirits/paint thinner will work, you may wish to use a commercial oil or grease remover to eliminate these stains. This stage of the cleaning process is very important, since the stain will not adhere properly to concrete contaminated with oil or grease. It may be necessary to do several applications of the cleaner to achieve a satisfactory result. Blotting the concrete with a cloth or paper towel, after the liquid cleaner has been applied, will help to remove the oil or grease stain. It is advisable to treat the areas that have been cleaned of oil and grease with a solution of TSP to completely eliminate any oily residue.

Mildew is best treated with pool chlorine (10% Sodium Hypochlorite) or household bleach ( 5% Sodium Hypochlorite). Unless mildew staining is extreme, a solution of 1 quart bleach (or 1 pint pool bleach) to a gallon of water should do. It can be applied with a garden watering can, or a chemically resistant pressure sprayer. If the first application is inadequate, try a second application, with a stronger solution. If you do not have the use of a pressure washer, the addition of a cleaning concentrate, like TSP, (refer to container for quantity), will help you remove tire marks, etc. It will help the process if you also scrub the mildewed areas with the push broom. Again, rinse the surface to remove mildew and chemicals.

The final cleaning procedure (with or without a pressure washer) involves the application of a solution of 1 part Muriatic acid to 2 parts water. Make sure that you add the acid to the water and not the reverse. It is also imperative that you protect yourself from the extremely caustic effects of Muriatic acid by wearing rubber boots, rubber gloves and goggles.

Using a plastic garden sprinkler, apply the acid mixture over the entire concrete surface and allow it to remain for 20 minutes. Thoroughly rinse the concrete surface with water at this stage, or preferably, do the same with a pressure washer (wearing rubber boots).

At this point you have to hope that for at least the next 24 hours it is warm, not too humid, possibly windy and it does not rain. With luck, you will be ready the next day to apply the very important prime coat of concrete stain

APPLYING STAIN

The first or "prime coat" of concrete stain will ultimately determine the overall quality and durability of the project. In order to assure this, it is essential that the concrete surface be clean of all contaminants, minutely porous and thoroughly dry, in order for the prime coat of stain to penetrate as deeply as possible into the concrete. In addition, if the concrete was recently poured or patched, it is necessary to allow the concrete to cure at least 45 days before applying stain and the surface must not have been previously painted. To allow for maximum stain penetration, do not apply the prime coat if the concrete is very hot.

Measure the area to be stained. Depending on porosity of the concrete, a gallon of stain will cover from 150 to 300 sq. ft. This makes estimating your requirements quite difficult, but any left over can be used later for touch-up or re-coating. If the stain is being applied indoors, make sure you have adequate ventilation and that no sparks or open flames are present. The Xylene solvent in this stain is extremely flammable and you should take every possible precaution when handling it. Provide a traffic barrier around the site to prevent accidental foot or vehicle traffic on the recently stained surface.

 To improve the penetration of the prime coat, use the 2 gallon metal pail to mix 1 gallon of the specially formulated H&C concrete stain with one gallon of H&C D100 solvent. Stir well and transfer into the metal roller tray. Apply the stain liberally, to encourage deep penetration.

 If there are grooves or score lines in the concrete use a brush to add extra stain to these areas prior to rolling. The surface will dry to touch in 15 minutes, allow foot traffic in an hour and permit re-coating after 12 hours. Try to select a day when no rain is forecast for 2-3 hours after the stain is applied and do not apply any coat later than 3 hours before sundown, otherwise the surface may not exhibit a uniform color. This is most important when applying the final coat. If you are staining a previously un-coated surface that will experience heavy traffic, such as automobiles, it might be wise to apply a second coat of 50/50 stain and solvent. Follow the previous application instructions.

 The final coat should be full strength and contain an anti-slip additive, to reduce the chance of slipping when the surface is wet. Add 0.2 lb. of Rhino Hide skid-resistant (a small container) to a gallon of stain. Mix thoroughly and stir frequently while applying the stain to maintain consistency. To ensure that the final coat has a uniform appearance, roll over the recently stained concrete surface with a dry roller to eliminate lap marks before the stain has dried. This should be done as each section of concrete is stained. Since the final coat is thicker, allow an hour or longer before walking and at least 72 to 96 hours before driving on the treated surfaces. 

A solvent based stain adheres extremely well to any existing solvent stain coated surface because the solvent partially dissolves the previous coat and bonds to it. This allows subsequent coats to be applied without the use of primers or the traditional need for sanding. However, it is essential that the surface to be re-stained be clear of mildew, oil or grease. This can be accomplished by following the previously described procedures. To maintain the skid resistant properties of the re-coated surface, the addition of some (probably 1/3 to ½ as much) Rhino Hide powder to the stain is advisable.

MAINTENANCE

You will find that your newly stained concrete looks good and will require much less effort to keep clean and stain free than untreated concrete. However, nothing lasts forever, not even concrete stain. Although the stained surface can be repeatedly re-coated with excellent inter-coat adhesion, precautions can be taken to minimize re-coating or covering blemishes. Care should be taken to avoid contacting the stained surface with the following chemicals: gasoline, Muriatic acid, concentrated garden chemicals, full strength bleach, plus various solvents such as acetone and lacquer thinner. These can either discolor or dissolve the stain and blemish the appearance of the surface. This will not affect the sealing properties of the stain, but may necessitate recoating, in order to maintain a uniform surface appearance.

Grease and oil stains can be removed by wiping with a dry cloth, or paper towel. If that is not adequate, use some detergent, or TSP and water. Mineral spirits-based paint thinner can also be used on stubborn grease or oil stains. If rust or leaf stains occur, Rustaid can be used to eliminate the brown discoloration. Take care to apply Rustaid (reduced with water - 1qt. Rustaid to 2 qts. water) on a wet concrete surface, in the area of the stain, and scrub till the stain is removed; then flush with water. Reducing the concentration of Rustaid will avoid bleaching the finish. To remove blemishes caused by mildew or tire marks, scrub them with a weak solution of 8 oz. (a cupful ) of bleach and a quarter cup of TSP in 2 gallons of water. Rinse the surface with water as soon as the blemish disappears to reduce the chance of surface discoloration. Since any stain which might appear is only superficial (because it is unable to penetrate the concrete) any subsequent cleanup is much easier.

Although a pressure washer can be used to maintain any stained surface, it is recommended that surface blemishes/stains be treated first with the previously described chemicals and/or be wiped up. This will avoid the chance of either spreading the contaminant, or damaging the stained surface through the use of excessive pressure while attempting removal of the stain.


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Last updated: 03/06/2012