Pyrite removal (commercial)
Problems
Pyrite
The presence of pyrite in the backfill under the concrete slabs or in the concrete produces sulfuric acid, a substance which causes the bursting of the stone and swelling of the backfill.
Fuel (Oil)
Earth contaminated with fuel that pollutes indoor air and the groundwater.
Symptoms
Pyrite
- Cracks in the basement and in the garage foundations.
- Cracks and uprising of the basement and the garage floors.
- Presence of white powder near the cracks
Oil
- Fuel odors (fumes) in the air
- Presence of oil on the surface
Causes
Pyrite
Use of backfill containing pyrite (stone non DB certified)
Oil
Old heating oil tanks buried or leaking.
Solutions
Pyrite
A laboratory test shows if the stone in the backfill has a high swelling potential. If this is the case, you must excavate the backfill and replace with crushed stone – DB certified (without swelling potential).
Oil
The backfill should absolutely be removed.
Work to be performed
Pyrite and/or oil.
- Crush the damaged existing concrete
- Remove the backfill or any contaminated soil
- Spread and compact a new backfill of stone DB certified
- Make a new concrete slab