What problems are common with anti-static raised access floors in "humid environments"

In humid environments (such as during the rainy season in southern China, in underground equipment rooms, and near water), anti-static raised flooring, due to its material properties and structural design, is susceptible to moisture erosion, leading to a series of problems that affect its performance and service life. The following are common problems and targeted preventative measures:

I. Common Problems with Anti-Static Flooring in Humid Environments

1. Substrate Swelling and Deformation, Causing Warping and Cracking

The substrates for anti-static raised flooring are often made of particleboard, medium-density fiberboard (MDF), calcium sulfate, or cement composite boards. These materials will expand due to prolonged exposure to moisture:

Symptoms:

Floor panels bulge at the edges and in the middle, forming gaps or uneven heights at joints. In severe cases, panels may crack or break, compromising pedestrian safety and overall smoothness.

Cause:

The non-moisture-resistant substrate has a high rate of water absorption and expansion (for example, ordinary particleboard can expand by 5%-10%), exceeding its structural capacity and causing deformation. 

2. Failure or instability of antistatic performance

The core function of antistatic flooring relies on a conductive surface layer (such as conductive adhesive or antistatic coating) or conductive fibers in the base material. Moisture can disrupt this system:

Symptoms:

The surface resistivity deviates from the standard range of 10Ω-10⊃1;Ω (too high becomes insulating, too low can be conductive and harmful). Static electricity cannot be effectively dissipated, increasing the risk of electrostatic breakdown in equipment.

Causes:

The conductive layer oxidizes, peels off, or separates from the base material when exposed to moisture, disrupting the conductive path.

Moisture forms a conductive film on the floor surface, causing an abnormal decrease in resistance (e.g., below 10Ω), creating a "leakage" risk.

3. Failure of edge sealing, exacerbating internal moisture.

Edge treatment is the first line of defense against moisture. In humid environments, the following can easily occur:

Symptoms:

Edge banding (PVC, rubber, etc.) softens, peels off, or separates from the base material due to moisture, exposing the underlying base material. Welded seams crack due to moisture penetration, losing their sealing properties. 

Cause:

Edge sealant loses effectiveness when exposed to water, or thermoplastic materials (such as PVC) swell in high humidity, weakening the bond with the substrate.

4. Rust on brackets and connectors affects structural stability.

The supporting brackets of anti-static flooring are often made of steel (galvanized or chrome-plated), which is prone to rust in humid environments.

Symptoms:

Rust spots and oxide layers appear on the bracket surface. In severe cases, the brackets may deform or break, reducing the floor's load-bearing capacity or even causing collapse.

Cause:

Moisture in the air combines with oxygen and salt (such as in coastal areas) to accelerate electrochemical corrosion of steel, damaging the surface rust-proofing layer.

5. Mold growth, polluting the environment and accelerating material aging.

High humidity (relative humidity >70%) environments are prone to mold growth under and on the floor.

Symptoms:

Black or green mold appears on the floor surface or at joints, emitting an unpleasant odor and contaminating clean environments (such as laboratories and medical equipment rooms). 

Cause:

Mold feeds on organic matter in the substrate (such as the wood fibers in particleboard). Moisture provides a breeding ground for its growth and accelerates substrate degradation.

II. Preventative Measures in Humid Environments

To address the above issues, comprehensive prevention measures are needed from four perspectives: material selection, installation techniques, environmental control, and routine maintenance:

1. Prioritize substrates and surface materials with excellent moisture resistance

Substrate:

Avoid using ordinary particleboard. Prefer moisture-resistant substrates, such as:

Calcium sulfate substrate (water absorption expansion rate <0.3%);

Galvanized steel-wrapped composite substrate (isolates moisture contact);

Solid PVC substrate (non-absorbent, suitable for high-humidity environments).

Surface Treatment:

Choose a waterproof and antistatic coating (such as epoxy antistatic paint) or a fully sealed structure (such as antistatic PVC flooring) to reduce moisture penetration paths.

2. Strengthen the sealing of edges and joints

Upgrade edge treatment:

Use hot-melt welding (for PVC/vinyl flooring) or metal edging with sealant filling instead of conventional adhesive edge banding to improve edge waterproofing. 

Joint Treatment:

During installation, fill the floor joints with mildew-proof and antistatic sealant (such as silicone conductive sealant) to prevent moisture infiltration and ensure antistatic continuity.

3. Moisture-Proofing the Subfloor Before Installation

Floor Pretreatment:

Before installing the antistatic floor, waterproof the subfloor with a polyurethane waterproof coating or waterproofing membrane to prevent moisture from seeping up from below.

Moisture-Proof Isolation:

Install a PE moisture-proof membrane (thickness ≥ 0.2mm) between the floor and the floor support to create a physical barrier and reduce direct contact between ground moisture and the floor substrate.

4. Control Ambient Humidity to Reduce Moisture Accumulation

Forced Dehumidification:

Install an industrial dehumidifier in enclosed spaces (such as computer rooms) to maintain a relative humidity of 40%-60% (in compliance with the Data Center Design Specification GB50174) to prevent condensation. 

Ventilation Optimization:

If using downflow air conditioning, ensure smooth ventilation of the static pressure box under the floor to remove moisture through airflow. Regularly open the floor panels to check for water accumulation or condensation underneath, and clean them promptly.

5. Regular Inspection and Maintenance to Address Potential Hazards

Humidity Monitoring:

Install temperature and humidity sensors under the floor and indoors to monitor humidity changes in real time and initiate dehumidification immediately when the threshold is exceeded.

Performance Testing:

Test the anti-static performance of the floor monthly using a surface resistance tester to ensure resistance values are within the specified range. Check the integrity of edge banding and seams, and repair any lifting or peeling immediately.

Cleaning Standards:

Avoid mopping the floor directly with a damp mop. Use a dedicated anti-static cleaner (neutral, without excessive moisture) and wipe the surface dry promptly.