Our friends at Euclid Chemical helped us create a step-by-step guide for concrete stamping. The video shows an high level overview of the process and below you'll find more details to follow along for your next decorative concrete project. Texture mats and concrete stamping tools/accessories are available at your local Harris. Some locations let you rent stamps, all can help you pick the right products. The clip is about 12 minutes long.

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 Preliminary work prior to concrete pour:

  • Provide a well compacted base of gravel approximately 4"-6" deep.
  • Set edge forms to provide 4" - 6" of 3500-4000 psi concrete containing a blend of 1/2" coarse aggregate.
  •  Backfill the outside of the edge forms to within 1'-2" of the top of the form.
  •  Ensure that all form pins, nails, or supports are below the top level of the form so that they do not obstruct the stamps.
  •  Fine grade the gravel the day before the pour and compact.
  •  Determine the location of the expansion joints. The expansion joint should be place increments equal to 4 x the width of the walkway.
  •  The expansion joints should be set using form spreaders so that they remain straight and at the proper height equal to the top of the walkway surface.  The spreaders are removed during the concrete placement.
  •  Place the welded wire mesh in the forms. The mesh should not run through or under expansion joints and should be 2"-3" clear from all outside edges.  The mesh can also be place on chairs to provide the proper height within the concrete. On a typical sidewalk pour the mesh is placed at the midpoint of the walkway thickness.
  •  About 1 hour prior to the pour the subgrade gravel should be dampened in order to prevent the premature drying of the concrete. This is especially important in hot/dry conditions.
  •  Ensure that all tools, stamps, pigments, evaporation retarder, and other accessories are on site prior to the ready-mix truck's arrival.
  •  Determine that the correct integral pigment is available and arranged so that the correct amount matches the ready-mix truck's payload.
  •  Cover and protect adjacent surfaces with plastic to help with clean up after the pour.
 When the truck arrives on site:
  • Check the load batch ticket to ensure that the proper mix and quantity has been delivered.
  •  Add the integral pigment o the ready-mix truck and have the driver mix for 5 minutes on 15-18 RPM. It's very important to time this part of the operation to ensure that all pigment has been mixed in thoroughly.
  •  The final consistency of the concrete prior to placement should be between a 5"-6" slump.

Placing the Concrete:

  • Determine the best location to start for the site. Usually the concrete placement is best working from the lowest point to the highest point. Some job conditions may prevent pouring from low to high and the slump may have to be reduced to accommodate this direction.
  •  If chair supports are not used to hold the wire mesh in position, use a narrow strip of concrete from the truck first to set the mesh prior to pouring the forms to full height (as seen in the video).
  •  Pour the concrete just above the top of the forms and grade level to that height.
  •  Screed the excess concrete towards the ready-mix truck which will allow the other workers to aid in removing the excess into the low area. Screeding the concrete should be within 3'-6' of the placement so that excess concrete can be removed easily.
  • Immediately after screeding a bull-float should be used to help flatten and consolidate the top surface of the concrete.
  •  An evaporation retarder (e.g. Euclid Chemical Eucobar) should be applied using an appropriate sprayer to help reduce the amount of moisture loss in the concrete while awaiting the final finishing operation.
  •  Magnesium hand floats should be used to level and smooth around the edges and fill in any low areas.
  •  Edgers should be used along all edges and expansion joints which provide an eased edge and prevent chipping at the edges.
Application of the Accent colors:
  •  Apply color hardener as soon as possible. As soon as the hardener has been applied it should be troweled in slightly. The hardener should not be applied into ponding bleed water.
  •  The color hardener is being applied very sparsely to produce light shades, veins, and contrasts to the base concrete color. It is important not to work the hardener too much as that will bury it into the base concrete and cause it to become lost. Reapply if necessary to achieve the desired effect on the whole surface.
  •  Generally 3 colors of hardener are used to produce contrasting accent colors on the base concrete to produce a consistent yet inconsistent look.  Very much like natural stone that has pockets of color or veins.
  •  In addition to 2 color hardener accent colors I like to use a third that closely resembles the base concrete color being used.  This third color acts as an "eraser" in the event too much of the accent colors are used.
  •  Using a trowel, try to sweep the color in one direction to produce a fanned out or wash of the color hardener.
  •  When all color hardener has been placed, finished to the desired look, and the concrete has an even smooth texture absent of tool marks, the release material can be applied.
  •  The Color Release powder being used in the demo is much easier to apply evenly to the surface compared to standard antique release powders.
  •  The antique or color release acts as a fourth color on the concrete and also provides an antiquing effect.  
  •  The release powder prevents the stamps from sticking to the concrete pour thus helping to produce a very natural looking texture on the concrete when the stamping tools are applied.
  •  Ensure all of the concrete surface has a even light coating of Release powder.  
  •  Applications of excess release powder that form piles or heavy thick areas should be blown off with a leaf blower so that the stamping tool can leave an accurate impression in the concrete.
Stamping:
  •  Once the surface has been treated with release powder the edges should be stamped using a small flexible texture mat that matched the overall pattern.
  •  The texture tool should always be rotated slightly after each stamping so that adjacent areas do not leave a noticeable pattern in concrete.  Random textures are the name of the game in order to produce a surface that is "second only to nature".
  •  The full size Texture mats can be placed and stamped when the surface is capable of accepting the weight of the worker without sinking in more than 3/8".
  •  This may be hard to judge sometimes however the Increte stamps and texture mats allow for earlier placement because of their stiffer yet very pliable composition.
  •  Texture mats offer the ease of stamping a large are quickly and efficiently yet producing a very esthetic surface that looks very convincing as real stone.
  •  The mats should be place so that they are carefully rolled down onto the concrete surface.
  •  Consecutive stamps should be place so they they overlap the preceding stamp by 1'-2'.
  •  The stamps should be placed so that they are rotated on angles and in different directions every time so that they do not repeat any patterns.
  •  Stamp the mats only as hard as necessary to produce the proper texture.  The amount of pressure will vary from beginning to end as the concrete is beginning to set.
  •  After the mats have been stamped, lift the overlapping stamp just enough to expose the mat underneath so that their overlap can be reversed.  
  •  This technique is used to eliminate any outlines of the stamping tool.  This will also allow the technician to remove the stamping tool without worry of damaging the placement.
  • Simply stand on the edge of the stamp that is now overlapping the adjacent stamp.  Grab the handle of the furthest point away from you and roll the stamp towards you until it is now 100% on the stamp you're standing on.  Then simply lift it up and walk it to the front of the line and set it down again on a fresh piece of concrete.
  • Texture mats also offer an ability to re-stamp over what has been done already in an effort to fix a problem area or blemish that may have been created.
  • Use the small flexible mats to get into tight areas as you stamp with the larger mats if necessary.

After the pour:

  • The concrete should be saw cut within 12 hours after placement if possible but no more than 24 hours.
  •  Wash the excess release powder off of the slab or walk with a garden hose before saw cutting.
  •  Saw cuts should be placed in order to achieve somewhat square pieces of concrete in order to reduce the possibility of cracking.  Ie: a 4' sidewalk should be saw-cut approximately every 4' in length and 25% of the slab thickness in depth.
  •  Measure the length of the distance between expansion joints and divide the distance up evenly and accordingly to the "square principle".

Sealing:

  •  **Wait at least 48 hours after saw cutting to apply any sealer.
  •  Many times the concrete is cleaned thoroughly after saw cutting and sealed with 2 heavy coats of a high gloss sealer. While this concept may look good for a month or so the final product can exhibit sealer failure which looks like a whitish film on the surface. What is actually happening is the moisture in the concrete is causing the sealer to delaminate as its breathability has been overwhelmed by the overabundance of moisture in the concrete trying to escape. In many cases sealers are applied twice their intended coverage rate which causes them to come loose and flake off.
  • Generally solvent based sealers are preferred for decorative concrete.  Sealers such as Euclid's EverClear 350, Diamond Clear 350, and Super Diamond Clear are all solvent based and designed to highlight the colors of decorative concrete and are slightly breathable when applied at listed coverage rates.
  • The surface of the concrete also needs to be cleaned properly to allow proper adhesion of the sealer.  Pre-wet the concrete and clean the surface with a very mild 1:10 solution of muriatic acid solution and a very soft acid resistant brush.  The acid solution should be sprayed on the wet concrete with an acid resistant sprayer.  Rinse the surface thoroughly with water before the acid solution dries.  The wear surfaces of the concrete surface should be free of release powder.  If this is not the case repeat the cleaning process.
  •  While some contractors prefer to use nothing but a pressure washer, pressure washing does not help open the pores of the concrete which is vital to a long lasting clear seal life. Also, the muriatic acid helps neutralize the hydrophobic chemical in the release agent. With a pressure washer it is also more difficult to remove release off the tops of the wear bearing surface without also removing it from the lower relief areas and grout joints.
  •  After the concrete has been cleaned and dried thoroughly apply 1 thin coat of Euclid Diamond Clear sealer with a pump sprayer.  Allow this to dry for at least 7 days before applying more sealer.  The idea of applying just 1 thin coat and walking away for a week or so is to ensure that the concrete has cured sufficiently and will allow the sealer to adhere properly.
  •  After the minimum 7 day waiting period a second coat can be applied if necessary.  If the concrete looks good and the sealer is even and the homeowner is happy... DON'T apply more sealer.

We hope this tutorial will help you with your next decorative concrete project! Our stores carry various products and our teams cannot wait to help you pick the right ones. Don't forget to share your pictures with us on Facebook or Instagram.

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