Installing Laminate Flooring over Concrete
This article speaks specifically to Armstrong and Bruce Laminate flooring and may pertain to other brands of laminate flooring. Armstrong Laminate Flooring can be installed over most subfloors and existing floors on all grade levels. All substrates must:
- meet applicable building codes
- be structurally sound
- show minimal deflection
- be dry, clean and flat
- Armstrong Laminate Flooring may be installed in bathrooms following the guidelines outlined in
the Bathroom Installation Section I.
- Armstrong Laminate Flooring is not recommended over most carpets or in high-humidity areas where the floor is normally wet—e.g., steam rooms, or saunas.
- The slope should not exceed 1″ in 6′ (2.54 cm in 1.83 m).
- Variations in subfloor flatness should not exceed 3/16″ in 10′ (4.76 mm in 3.05 m) or 1/8″ in 6′ (3.17 mm in 1.83 m). Level floors with a suitable cement-based self-leveling underlayment following the manufacturer’s recommended guidelines.
- Radiant heated subfloors should not exceed 85°F (29°C).
Concrete Subfloors Concrete floors must be cured properly and allowed to dry for at least 60 days after the curing process.
- Concrete floors must not show any signs of moisture or alkali.
- Use Quiet Comfort or Quiet Comfort Premium Underlayments for Laminate with no attached backing (or Moisture Barrier Sheeting for laminate with attached backing), butt the edges together and tape the seams with polyethylene tape.
Test for moisture in concrete prior to installation. Too much moisture can cause significant damage to laminate flooring.
- Tape 3′ × 3′ (91 cm × 91 cm) pieces of polyethylene film to the subfloor.
- After 24 hours, if moisture condensation appears on the film or the concrete appears dark-colored, it is likely excessive moisture is present and a Calcium Chloride test must be run.
The maximum acceptable moisture emission level for Armstrong Laminate Flooring installations is 5.0 lb./1000 sq. ft./24 hours (2.26 kg/101.6 m2/24 hours). If moisture emission level exceeds 5.0 lb./1000 sq. ft./24 hrs. The use of VapArrest S-135 Professional Moisture retardant system is recommended. When applied as recommended, the system will reduce water vapor transmissions up to 75% in areas with vapor transmissions as high as 12 lb./1000 sf/24 hrs. Select Here to Download Mohawk’s Laminate Flooring Guide