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: If boxes have been stored in a cold truck or warehouse below 50°F, let them sit in the install room for 24 hours before cutting. Rigid-core planks handle temperature change better than wood, but extreme cold can make the click-lock edges brittle during installation.

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: On older concrete slabs, we measure flatness in multiple directions — not just one straight line. A 3/16-inch dip in a 2-foot circle under a refrigerator telegraphs through even the thickest SPC eventually, regardless of what the 10-foot average says.

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: Bay Area homes near the water (Alviso, parts of San Mateo, coastal San Francisco) often have higher slab moisture than the test-day reading suggests — slab moisture fluctuates seasonally. If your slab tests at 85% RH in October, it may hit 95% in February. Budget for the 6-mil moisture barrier below either way.

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 recommend 6-mil polyethylene vapor barrier over every concrete subfloor regardless of test results. Seasonal moisture shifts, future plumbing leaks, and unseen slab cracks mean a clean moisture test today doesn’t guarantee a dry subfloor in five years. 6-mil poly is $30-50 for a whole room — inexpensive protection. Overlap seams by 6-8 inches, seal with waterproof tape, run 2-4 inches up the walls (hidden by baseboard). This is industry-standard per NWFA and what we’d do in our own home.

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: Customers sometimes ask about adding a thicker pad under Summit Collection for more softness. Don’t. The attached IXPE pad is engineered to work with the SPC core — adding a second pad creates an unstable stack-up that causes click-lock seam failure over time. The warranty specifically voids structural-integrity coverage if a non-manufacturer pad is used.

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: For rooms wider than 25 feet or longer than 40 feet continuous, add a T-molding expansion break. SPC is dimensionally stable but not dimensionally inert — large rooms need room to breathe. Ignore this on thicker SPC at your peril; the extra thickness makes seam pressure more pronounced when expansion has nowhere to go.

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: Turn the heating system on at least two weeks before installation to purge slab moisture. After installation, raise temperature in 5°F increments per day back to operating level. Never go from room-temp to full heat in one day — thermal shock can compromise the click-lock edges and IXPE pad adhesion.

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: Use a cleaner specifically labeled for luxury vinyl or SPC — Bona Pro Series Luxury Vinyl Floor Cleaner works well. Avoid ‘mop and shine’ products that leave a film; they trap dirt and dull the Ceramic Bead finish over time.

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: Steam mops are the #1 warranty-void cause on Vellichor Floors floors — Vellichor Floors’s master warranty explicitly denies coverage for any damage caused by steam cleaners, and the moisture/heat breaks down the adhesives in the plank construction. Customers sometimes say ‘but it’s waterproof’ — the core is waterproof; the seams and adhesives are not designed for pressurized hot water.

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: Office chairs with plastic wheels are harder on SPC than pet claws. Vellichor Floors’s warranty specifically excludes damage from caster wheels unless they’re wide rubber — swap plastic wheels for rubber or silicone, or use a chair mat. This is in the written warranty, not a suggestion.