Repairing poorly done crack repairs
a floor repair fails, the fix is often more difficult than for the original
problem. This is because the crumbling repair materials and sticky fillers now
have to be removed. Before long lasting repairs can be made, you need good
surfaces to adhere to. If you simply apply new repair materials to those that
have failed, what remains is likely to fail as well.
You can often repair these areas with 100%
solids epoxy, either with or without fillers like quartz or silica sand to
reduce cost and improve strength. Sometimes running a masonry blade down cracks
and joints will remove enough material to give a good bond. Pressure washers
will often blast out rubbery caulks and crumpling cement type materials. But all
too often the materials have to be chipped out manually, piece by piece with a
chisel or knife.
Topcoat repairs to floors are all too often so thin that they can't hold up to
point loads. These surfaces often crumble off and require the removal of the
entire coated surface. Another danger is having liquids soften the layer of
concrete between the two surfaces, breaking the bond. Thin set concrete coatings
have limited adhesion. These thin coatings are subject to having pockets blister
off the substrate which eventually crumble and become dust. Once hollow areas
are removed, filling with 100% solid epoxy can level those floors and seal them
from further damage.
Prep the surface with high alkaline, followed by an acidic cleaner and a couple
scrub rinses. When the floor is dry, you can pour 100% solids epoxy over the
area to be repaired. Then throw in small amounts of color quartz or silica sand
and use a squeegee to move the liquid back and forth over the holes. By doing
this, the heavier quartz will sink to the bottom of those holes, over time. You
often have to squeegee a bit in one area and wait a few minutes to come back and
add more filler and agitation to allow those holes to fill to the surface. If
too liquid, the surface tension may allow the holes to appear concave or convex.
This requires smoothing them with a grinder after they harden. If done well,
this technique can bring the floor to level with a minimum of effort, producing
a surface that is going to adhere well and take significant point loads without
Here are the steps for repairing failed repairs:
Use a mallet and scraper to find areas of
substrate that are about to come loose and remove them.
Clean the surface using a rotary scrubber
with a high alkaline cleaner followed by a high acidic cleaner and scrub rinse.
After drying, use a 4” grinder with a masonry
wheel to bevel the edge of craters so edges are about 45 degrees towards the
Sweep off excess ground material.
Use a glazing compound and putty knife to
fill hairline cracks so the epoxy will not sink in and continue to show them.
For larger cracks, fill sand into them using
a broom until sand becomes visible which will keep your epoxy from sinking
through the cracks. Make sure no sand remains on the surface.
Mix up your two-part, 100% solids epoxy in
one gallon batches so it stays as fluid as possible.
Use a brush and 3/16" lint-free roller to cut
in around the edge of the room and around legs and other obstacles.
Mix more epoxy just as you need it so you are
not working with thicker, tackier material that is more than 15 minutes old.
Dip your roller and apply to all flat areas.
Pour epoxy directly into any cavities and
Use your roller or a soft squeegee pulling
towards you and lifting as needed to achieve level surfaces over each hole or
Allow the floor to harden about 15 hours and
then use a 3M-type sanding screen on your rotary scrubber to remove high spots
Sweep off dust and residue caused by the
Repeat steps 5 through 12 for a second coat
Following these steps will result in repairs
which have a good chance of lasting. A heavy impact to the floor may still make
layers of a cement-type patch let go, but more often than not, you will avoid
additional problems. Your floor will be relatively flat and good looking while
being easy to keep clean and maintain.
Durall Industrial Flooring supplies kits of materials that are customized to
owner specification and delivered directly to the job site. Kits include full
directions and 24/7 help lines staffed by seasoned flooring experts, so
professionals and amateurs alike can successfully install a quality floor.
For a detailed quote of materials needed to accomplish these repairs, please
visit our free cost analysis page at
For more information, contact Chris Biesanz
at firstname.lastname@example.org or phone 1-800-466-8910 or 952-888-1488
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