Fuel Oil or Petroleum Odors Coming Through Concrete Floors
Cleaning and Epoxy Sealing System
Concrete floors that have been exposed to fuel oil, petroleum products, or similar contaminants can sometimes continue to release odors long after the original spill occurred. In many cases the odor is coming from petroleum contamination that has been absorbed into the pores of the concrete.
The goal of this procedure is to clean the concrete thoroughly and install an epoxy barrier system that can help block and isolate remaining contamination.
Odor problems are not always located only in the slab itself. Odors may also migrate through cracks, expansion joints, drains, walls, or moisture vapor movement in the slab.
Recommended System
Step 1 - Mechanical Preparation
Grind the concrete to solid, sound concrete. The purpose of grinding is to remove weak surface material, previous coatings, and heavily contaminated surface layers.
After grinding:
- Sweep the surface thoroughly.
- Vacuum the floor carefully to remove all grinding dust and loose material.
Dust left on the surface can interfere with bonding and may trap contaminants beneath the coating. If odor contamination is severe, more aggressive grinding may be required in those areas.
Step 2 - Degrease and Clean the Concrete
After mechanical preparation the concrete should be cleaned using a commercial grade petroleum cleaner or degreaser. A good source for these cleaners is usually a reputable local janitorial supply house, which often carries strong petroleum cleaning products designed for industrial surfaces.
Follow the cleaner manufacturer's instructions carefully, including dwell time, agitation, and rinsing if required. The objective is to remove as much petroleum contamination from the concrete pores as possible before installing the coating system.
Step 3 - Grind Again if Needed
After degreasing and cleaning, inspect the surface. If residue or contamination remains, grind those areas again to remove remaining contaminated concrete.
After grinding:
- Sweep the surface thoroughly.
- Vacuum the floor again to remove all dust and debris.
The final surface should be clean, solid, and porous, ready for bonding of the primer.
Step 4 - Apply Epoxy Primer
Install one coat of Epoxy.com Product #201 Primer: https://www.epoxy.com/201.aspx
Allow the primer to harden and test for bond in the most contaminated areas. If there are bonding problems, scrape or grind off the affected areas and reapply primer. The primer must be recoated within the recommended recoat window (typically 24 hours).
Step 5 - Apply Two Coats of Epoxy Topcoat
Install two coats of Epoxy.com Product #2: https://www.epoxy.com/2.aspx
These coats increase film build and chemical resistance and help form a barrier that reduces odor migration through the slab.
Optional System Upgrade - Decorative Chip Flooring
Instead of a smooth coating system, you may install a decorative broadcast system such as: https://www.epoxy.com/chip.aspx
Chip flooring provides a thicker flooring system with decorative chips and a protective topcoat.
Important Notes
Odor problems may also originate from other pathways including:
- Cracks or control joints
- Expansion joints
- Wall-floor intersections
- Plumbing penetrations or drains
- Moisture vapor movement through the slab
If odors persist after coating, these pathways may need to be investigated and sealed.
Common Questions
Does epoxy remove petroleum odor from concrete?
No. Epoxy coatings do not remove petroleum contamination from concrete. The purpose of the system is to reduce odor migration by sealing the concrete surface.
Why is grinding necessary?
Grinding removes weak surface concrete and heavily contaminated layers while opening the pores of the slab. This improves both cleaning effectiveness and coating adhesion.
Will this completely eliminate the smell?
In many cases the system can significantly reduce or eliminate petroleum odors coming through the floor. However odors may also travel through cracks, joints, drains, wall-floor intersections, or moisture vapor pathways.
Can this system be used in basements?
Yes, but basement slabs may also have moisture vapor issues which should be evaluated before installing coatings.
Can decorative flooring be installed instead?
Yes. Decorative chip flooring systems can be installed over the prepared floor for additional thickness and durability.
Need Help Selecting the Right System?
If you are dealing with petroleum contamination or persistent odors in concrete floors, Epoxy.com Technical Support can help you determine the best preparation and coating system.
Epoxy Systems, Inc.