Plainfield Epoxy Flooring installs basement floor epoxy for homeowners in Plainfield, IL, and has 20+ years of coating work behind every basement job, including homes in surrounding cities including Shorewood, Minooka, North Aurora, Warrenville and Lemont. A basement floor is the hardest residential slab we coat, because it sits below grade with soil and groundwater on the other side of the concrete, and moisture decides whether a coating lasts.
That is why a basement job starts with water rather than color. We look at where any water has come in before, check the sump and floor drains, and measure the moisture moving through the slab before choosing a system. Sometimes the answer is a standard epoxy, sometimes a moisture-mitigation primer under it, and sometimes the honest answer is that the water has to be solved first.
Once the system is chosen, the proposal names the product, the layers and the finished thickness, and it states plainly that the coating is a floor finish, not waterproofing. Every home job also gets a written contract and the Home Repair: Know Your Consumer Rights pamphlet that the Illinois Home Repair and Remodeling Act calls for.
Reading the Basement Before Any Epoxy
Where the Water Comes From
Water reaches a basement floor in a few different ways: through cracks in the slab or walls, through the cove joint where the floor meets the foundation, up through the slab from below, or as condensation on a cool floor in humid summer air. Each one needs a different response, and a coating fixes none of them by itself.
We ask about past water events, look for stains, tide marks and rust on metal shelving legs, and check how the sump behaves. That history is often more useful than a single test, because a slab that tests dry in October can behave very differently after a wet April.
Hydrostatic Pressure From Below
When groundwater rises around the foundation, it pushes up on the underside of the slab, and that pressure can force water through hairline cracks and even through the concrete itself. A coating bonded to the top of a slab under that pressure is the first layer to give, blistering or lifting in sheets.
If a basement shows signs of hydrostatic pressure, we tell you that the drainage, the sump or the perimeter drain tile has to be addressed before any coating, and we can point you toward the kind of contractor who handles that work. Coating over the problem only hides it until the next wet season.
Efflorescence and Old Water Marks
The white, crusty powder that shows up on basement floors and walls is efflorescence, mineral salts carried by moisture and left behind when the water evaporates. It is evidence that moisture is moving through the concrete, and it also sits as a loose layer that no coating can bond to.
We grind efflorescence off during prep and treat its presence as a reason to test carefully, not as a cosmetic issue. Where it keeps returning in the same spots, those areas get extra attention in the moisture readings and in the choice of primer.
Flood History Along the DuPage River
The DuPage River runs through Plainfield, and the Will County Stormwater Management Planning Committee commissioned USGS flood-inundation maps from Plainfield to Shorewood after floods in 1996, 2007 and 2008, with further overbank flooding in 2013. Homes in low-lying areas near the river may have had water in the basement during one of those events.
After any flood or major storm, a slab can hold moisture for a long time after the surface looks dry. We test before coating rather than trusting appearance, and we do not describe a coated floor as flood protection, because it is not.
Testing and Prepping the Basement Slab
Calcium Chloride and Relative Humidity Tests
We measure basement slabs with ASTM F1869 calcium chloride kits, which read the vapor emission rate at the surface over a set period, or with ASTM F2170 in-situ relative humidity probes placed in drilled holes in the slab. The probe method reads conditions inside the concrete, which is often more telling in a basement than a surface reading.
A quick ASTM D4263 plastic sheet test can flag an obviously wet slab, but it does not tell us how much moisture is moving. The real tests give numbers that can be compared against the thresholds in ASTM F710 and the coating manufacturer’s own limits.
Moisture-Mitigation Primers
When the numbers are above what a standard epoxy tolerates but the basement is not actively taking on water, a moisture-mitigation primer can be applied as its own layer beneath the coating. These primers are designed to handle a higher vapor load and give the epoxy above a stable surface to bond to.
We include one only when the readings call for it and write it into the proposal as a separate line item. Adding it to every quote would inflate the price of dry floors, and leaving it off a damp floor to win a job would set the coating up to fail.
Grinding Away Glue, Paint and Sealers
Many basements have carpet adhesive, tile thinset, old paint or a sealer from years ago. We diamond grind the floor to remove all of it and open the concrete to a surface profile suited to the coating, and we never acid etch, since acid does nothing to remove adhesives or sealers and leaves residue behind.
Grinding in a finished basement is done with vacuum-shrouded equipment so the dust is captured at the grinder. We seal off the work area from the rest of the house where we can and never wash grinding residue into a floor drain.
Crack Repair and the Cove Joint
Basement slabs commonly have shrinkage cracks and a gap at the cove joint where the floor meets the wall. Stable floor cracks are filled with a material compatible with the coating, while the cove joint is often left as it is, because sealing it can trap water that a perimeter drain system relies on to reach the sump.
Coating Around Sumps, Drains and Mechanicals
Sump Pits and Perimeter Drain Tile
Many basements here drain through perimeter drain tile into a sump pit, and the floor around it has to let water reach the pit. We stop the coating cleanly at the sump basin and keep the lid accessible, and we never coat in a way that blocks a drainage path the house depends on during a heavy rain.
Floor Drains and Laundry Areas
Floor drains near water heaters and laundry machines are left fully functional, with the coating tapered neatly to the drain body. In laundry areas we often add a light aggregate in the topcoat for grip, since detergent and water on a smooth coating can be slippery.
Radon Systems Stay Untouched
Many homes have a radon mitigation system with a pipe through the slab, and newer Illinois homes are built with passive radon piping. We coat around those pipes without disturbing their seals, and we do not sell a floor coating as radon reduction, because in Illinois that work requires an IEMA radon mitigation license.
Finishes and Pricing for Basement Floor Epoxy
Finishes for Every Room Downstairs
A family room may suit a decorative flake or metallic finish, while a workshop or storage room is better served by a durable solid color that shows dropped hardware. A home gym needs a topcoat that tolerates rubber mats and weights, and a laundry room benefits from texture.
Because basements have little natural light, standard epoxy yellowing is less of an issue than in a garage, but we still use stable topcoats near windows and walkouts. The finish is chosen room by room rather than one system laid everywhere by default.
What Moves the Price
We price basement floor epoxy per square foot for the system on your slab. Moisture readings that call for a mitigation primer, the amount of adhesive or paint removal, crack repair, the number of rooms and edges, and the time spent detailing around sumps, drains and mechanicals all move the number.
What the Warranty Will Not Cover
Coating warranties nearly always exclude moisture first, which matters more in a basement than anywhere else in the house. They also exclude slab movement, new cracking and damage from flooding, and we read those exclusions out before the job is sold so the limits of the coverage are clear.
- 20+ Years of Floor Coating Work
- Moisture Testing in Every Scope
- Free Written Estimates