Acclimation

Regular plank: acclimate 24-48 hours in 65-85°F. Herringbone (VC-709H): acclimation not required, but install in 55-85°F climate-controlled environment. Store cartons flat, no more than 5 boxes high.

Pro tip: SPC doesn’t need acclimation the way hardwood does, but the install room should be at its normal operating temperature during install — not 60°F in winter or 90°F in summer. Install at the temperature the room will typically be. This minimizes edge-gap changes after the floor settles.

Subfloor flatness

Subfloor must be smooth, dry, structurally sound, and flat within 3/16″ in a 10-foot radius (or 1/8″ in 6 feet for herringbone). Grind down high spots and fill low spots with a latex-fortified cementitious patching compound (3,000 psi minimum). Wood subfloors require 3/4″ minimum thickness over 19.2″-on-center joists.

Pro tip: If the subfloor has small unevenness that can’t be fully leveled, thicker SPC provides more physical forgiveness — 8mm and 10mm planks bridge minor dips and bumps better than 6.5mm. Rule of thumb: under 1/8-inch variance over 10 feet, any SPC thickness works. 1/8 to 3/16-inch — go 8mm minimum. Over 3/16-inch, the subfloor needs leveling compound before install regardless of plank thickness. Important caveat: even if thicker SPC masks the problem physically, manufacturer flatness specs are flatness specs. If a warranty claim gets filed later and the inspector measures out-of-spec subfloor, that goes in the report as installation-related — regardless of whether thicker plank was used to “compensate.” Thicker SPC is forgiveness for minor borderline cases, not license to skip subfloor prep.

Moisture testing (concrete)

On concrete, moisture vapor transmission must not exceed 8 lbs/1000 sq.ft./24 hours per ASTM F-1869 (Anhydrous Calcium Chloride Test). Internal relative humidity must not exceed 85% per ASTM F-2170 (90% for herringbone). Concrete pH must be between 7-10. New concrete slabs must cure for at least 90 days.

Pro tip: One moisture test is a snapshot, not a seasonal profile. Slab moisture in the Bay Area can swing 10-15 percentage points between wet and dry seasons. If your test passes in summer, retest in winter before committing, or just install the 6-mil vapor barrier as standard practice.

Moisture barrier (concrete subfloors)

A minimum 6-mil poly film moisture barrier between concrete and the SPC plank is REQUIRED for ALL concrete substrates as a vapor retarder. This is mandatory for warranty coverage.

Pro tip: We’ve replaced too many vinyl floors that failed from slab moisture in Bay Area homes — many built on fill or near old creek beds. Even when the slab tests dry today, seasonal water table shifts can push moisture up through the concrete years later. 6-mil polyethylene sheeting is $30-50 per room and takes 20 minutes to install. Always install it over concrete, regardless of what the manufacturer spec says is “required.”

Underlayment (do not replace the attached pad)

Planks have 1.5mm IXPE pad pre-attached. Do NOT use additional underlayment under the SPC planks — adding extra cushion voids the warranty and can cause locking failures.

Pro tip: The attached IXPE pad is part of the warranty contract, not an accessory. Adding foam, cork, or rubber underneath voids the structural integrity coverage. If the subfloor is irregular, fix that with leveling compound first — don’t stack pads to mask a subfloor problem.

Installation method

Float the planks (no glue, no nail). Regular plank: 5/16″ (8.2mm) expansion gap. Herringbone (VC-709H): 1/4″ (6.35mm) expansion gap; rooms larger than 900 sq ft require 1/2″ (12.7mm) expansion gap or transition moldings. Stagger end joints minimum 8″ row-to-row on regular plank. Use a tapping block — never strike the plank surface directly.

Pro tip: Check the manufacturer spec for T-mold requirements between rooms — some brands require a T-mold at every doorway, others allow continuous install up to a certain run length. Don’t skip the check. If you run one continuous floor through a kitchen into a hallway and into two bedrooms without T-molds, each room’s subfloor shifts slightly differently with seasonal humidity and thermal changes. That differential movement concentrates at the narrow door transitions, and within 1-2 years you’ll see click-lock seams crack right at the doorways — not mid-room, always at the pinch points. T-mold at each doorway absorbs the differential movement and isolates each room’s expansion from the next.

Radiant heat compatibility

Compatible with hydronic radiant heat only — NOT electric heating mats. Heating elements must be embedded in the subfloor with minimum 1/2″ separation from the flooring. Operate the radiant system at normal temperature for at least 21 days before installation (2 weeks for herringbone), then turn off 24 hours prior. Maximum subfloor surface temperature is 85°F at all times.

Pro tip: The surface temperature cap is the critical number. Hydronic systems typically run below spec naturally; electric mats can exceed it if the thermostat is mis-positioned. Position the sensor in the finished floor, not in the slab, and verify with an infrared thermometer before tiling furniture or rugs on top.

Daily maintenance

Sweep or vacuum regularly (beater bar OFF). Wipe spills with clean water and a damp (not wet) mop. Use cleaners formulated for vinyl flooring — never polishes, waxes, abrasives, or ammonia-based cleaners.

Pro tip: The fastest way to wear out the wear layer is tracked-in grit. Walk-off mats at every entrance plus twice-weekly vacuuming (hard-floor setting, no beater bar) in high-traffic areas buys years of finish life. The wear layer handles traffic; abrasive grit grinds it down prematurely.

What to avoid

Do not install over carpet, cushioned-back resilient flooring, or any floating/loose-laid surface. Do not install cabinets on top of the planks — install flooring around fixed cabinets.

Pro tip: Rubber- and latex-backed walk-off mats cause permanent yellow discoloration under SPC warranties. The rubber chemistry reacts with the wear layer over months. Use felt-backed or woven natural-fiber mats instead — and never leave any mat in place over a seam line.

Furniture and pet protection

Use felt protectors under chair and furniture legs. Wide rubber casters required on rolling chairs. Use a 1/8″ Masonite sheet to cover and protect the floor when moving heavy furniture or appliances.

Pro tip: If you have pets, avoid heavy wire-brushed or deeply-rustic surface textures. The deep grain grooves that make wire-brushed look authentic also trap pet hair, dirt, and grit. Vacuum can’t reach the deepest channels; over months, the floor looks permanently soiled even after cleaning. For pet homes, choose subtle-to-medium surface texture instead — still gets the wood-grain realism, skips the cleaning liability. Heavy wire-brushed SPC photographs beautifully in the showroom but doesn’t live well with dogs and cats.