Laminate Flooring · Click-Lock System
Laminate Installation Guidelines
Müller Graff laminate flooring uses a precision click-lock floating system. The installer is responsible for ensuring all conditions are met before, during, and after installation.
Section 01
General Overview
Laminate flooring is installed as a floating floor — it is not attached to the subfloor.
- Floating installation only — do not nail, staple, or glue to subfloor
- Click-lock system — no adhesive needed between planks
- Store laminate on-site 72 hours before installation at 40–70% RH and 15–30°C
- Document site temperature and RH before and during installation
Without documented acclimation conditions, future warranty claims may be denied.
Section 02
Jobsite Conditions
| Condition | Requirement |
|---|---|
| Indoor Temperature | 59°F – 86°F (15°C – 30°C) |
| Relative Humidity | 40% – 70% RH |
| Building | Fully enclosed — HVAC operational |
| Acclimation | 72 hours minimum on-site |
Section 03
Subfloor Requirements
Subfloor flatness is the #1 cause of laminate failures.
| Requirement | Specification |
|---|---|
| Flatness | 3/16" in 10 ft (4.76mm in 3m) — CRITICAL |
| Concrete Subfloor | Fully cured (60+ days), moisture tested |
| Wood Subfloor | Structurally sound, clean, dry |
| Existing Flooring | Can install over most hard surfaces if flat |
| Carpet | Must be removed — cannot install over carpet |
Moisture Testing
| Subfloor Type | Test Method | Max Allowed |
|---|---|---|
| Concrete | CM Test (calcium chloride) | ≤ 3 lbs / 1000 sq ft / 24 hrs |
| Concrete | RH Test (in-situ probe) | ≤ 75% RH |
| Wood | Pin-type moisture meter | ≤ 12% MC |
Section 04
Underlayment
| Subfloor | Underlayment | Vapor Barrier |
|---|---|---|
| Concrete | Required — foam or cork | Required — 6 mil polyethylene |
| Wood (above grade) | Required — foam or cork | Not required (can trap moisture) |
| Wood (below grade) | Required — foam or cork | Required — 6 mil polyethylene |
If installed over concrete, a 6 mil polyethylene vapor barrier must be added. Over wood, do NOT use a vapor barrier.
Section 05
Installation Steps
First Row
- Start from the left corner of the room, tongue side facing the wall
- Place 1/4" spacers between the plank and all walls
- Cut the last plank to fit — remaining piece starts the next row (if ≥ 12")
Click System
- Angle the long side into the previous row at approximately 20–30°
- Press down to click into place — do not force
- Tap the short end gently with a tapping block if needed
- Never use a hammer directly on the plank edge
Staggering
- Stagger end joints by a minimum of 12 inches between rows
- Random stagger pattern is recommended for natural appearance
- Avoid H-patterns — they weaken the floor and look unnatural
Final Row
- Measure and cut the final row to fit — maintain 1/4" gap
- Use a pull bar to engage the click system on the last row
- Ensure all spacers remain in place until installation is complete
Section 06
Expansion Rules
| Location | Requirement |
|---|---|
| All Walls | 1/4" minimum expansion gap |
| Fixed Objects | 1/4" gap around pipes, columns, door frames |
| Large Rooms | Transition molding required every 40 ft (12m) |
| Doorways | T-molding transition required |
| Room Changes | Transition at every room-to-room connection |
Never pin the floor against walls or fixed objects. Cover expansion gaps with baseboard — do not fill with caulk or adhesive.
Section 07
Special Conditions
| Condition | Requirement |
|---|---|
| Rolling Chairs | Soft rubber casters (Type W) required |
| Wheelchairs | Protective mat required in areas of regular wheelchair use |
| Kitchens | Wipe spills immediately — do not allow standing water at joints |
| Bathrooms | Not recommended — high moisture risk |
| Radiant Heat | Hydronic only — surface temp must not exceed 80°F (27°C) |
Section 08
After Installation
- Remove all spacers after installation is complete
- Install baseboard moldings to cover expansion gaps (attach to wall, not floor)
- Allow 24 hours before placing heavy furniture
- Maintain 40–70% RH and 59–86°F after installation
- Use felt pads on all furniture legs immediately
Reference: Müller Graff Laminate Installation Guidelines | NALFA Standards.