How to use Walttools Stampable Overlayment.

Don Ciesielski-Walttools

Overlays are a great, but underutilized, segment of decorative concrete. They allow you to take an old, plain, ugly slab or floor and transform it into a textured decorative surface, just like stamped concrete, without starting over. The following is an overview of the process.

It is important that the concrete you are going to use the overlayment on is structurally sound, clean, unsealed, or unpainted. Make sure it also free of curing compounds if this is a newer slab.  The existing concrete should be at least 30 days old. The slab will need to have a good profile so that the Over Eze has a good surface to bond to long term. Typically that is done with shot or sand blasting, grinding or acid etching.  

Clean & Degrease, Prep-

1. Degrease the concrete surface with C Cleaner. Mix according to the instructions, scrub it into the surface and clean thoroughly with water when finished. Make sure any latent oil or grease is not beading water in spots.
2. If shot blasting or grinding is your prep, proceed and completely rinse off any dust and residue. If you are not able to do either of those surface treatments, then etch the concrete surface with C Etch, a concrete etcher and remover. Mix according to instructions, work it into the surface and rinse and clean thoroughly when complete. Repeat if needed.  The surface should feel soft like sandpaper.
3. Protect all adjoining areas with plastic sheeting ir similar material to protect from the application of the overlayment system.
4. Apply Colloidal Tru Hard. Colloidal Tru Hard is a very economical concrete treatment that will reduce the transmission of moisture up thru the slab.  Most overlayment failure comes from a failure to bond issue. This products is a specialized concrete densifier that will improve the integrity of the slab and serve as a prebonder, improving bond strength overall. Apply in two treatments allowing the first to dry before the second.  Saturate and use a broom to eliminate puddling. Allow to dry for 24 hrs.
5. Applying the bonder. Mix Flexy Bo bonder 1:1 with water and apply to the surface with a 3/8 nap roller.  Roll thoroughly to avoid any puddling or obvious excess material bands from the roller. Allow to dry 1 to 12 hours before beginning the overlayment. Do not exceed 24 hrs.
6. If you have any major low points(more than 3/8 inch) from spalling, delamination, etc, you may want to apply a “bond coat”, filling those depressions. This is done by mixing up a batch of the overlay and filling those areas.  You may use a broom to apply some profile to that surface before it cures out.
7. If you plan to use stencils, you will often color a few batches a contrasting color that will show when the stencil is removed,  this layer is applied very thin, just as described in the following section. You will then place your stencils on this initial surface before applying your second coat.

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