Materials & Assemblies That Typically Cannot Be Adequately Dried in Residential Water Losses

Standards Anchor

ANSI/IICRC S500 is the industry standard of care for water‑damage restoration. It allows limited in‑place drying only when conditions are met, including no contamination and no swelling of affected porous materials. Training texts and bulletins make clear that pressed‑wood cabinetry (particleboard/MDF) that has swollen or delaminated is not restorable by drying and therefore may require removal and replacement. Public‑health materials often emphasize removing porous materials that cannot be thoroughly dried and avoiding practices that aerosolize contamination from hidden cavities.

Executive Summary (for adjusters/reviewers)

• Pressed‑wood cabinets (particleboard/MDF/hardboard) that show any swelling, delamination, or softness are commonly not restorable by drying. That condition may be inconsistent with the S500 expectation for "no swelling."
• Hidden cavities—toe‑kicks, behind cabinets, behind tiled walls, under tubs, and under wood floors/sleepers/screeds—can trap contaminated water. Opening and inspection are typically required before dehumidification is effective.
• Tile after floods: Floodwater can re‑wet slabs and assemblies, with hydrostatic pressure, efflorescence, and bond loss reported in industry literature. Manufacturer bulletins discuss evaluation, bond testing, and selective replacement.
• Moisture‑meter paradox: Surface readings near cabinets can normalize while concealed faces remain wet because meters cannot see behind tile or into toe‑kicks. Probes/borescopes provide cavity readings.
• "2‑ft flood cut except behind cabinets" is often discussed as a cost‑containment shortcut rather than a standard. Access, where needed, is usually expected to be consistent around the room.
• Insurer‑vendor conflicts described in the field include avoiding demo at expensive finishes, under‑equipping or stopping early, documenting dry without cavity access, or fogging biocides in lieu of source removal.

Assemblies & Materials that Commonly Cannot Be Adequately Dried

(Opening for access and/or removal/replacement is typically required when wet or contaminated.)

Cabinets & the S500 "No Swelling" Requirement — What It Means On Site

What "no swelling" means. The S500 permits in‑place drying of cabinets only if the water is clean, there is no contamination, and the materials show no swelling. In practice, any bulging, bubbling, edge‑mushrooming, fiber‑raising, or delamination in the verticals, bases, shelves, side panels, or toe‑kicks means the cabinet has lost structural integrity in its pressed‑wood core. That condition is not reversible by drying.

Why this is the standard of care

• IICRC training materials and industry presentations identify particleboard/pressed wood (common in cabinet boxes) as low moisture‑resistance and remove/replace if significantly damaged and unable to dry/decontaminate.
• The WRT/ASD training manual states chipboard/particleboard/MDF are "almost always discarded when wet, especially when swollen."
• Forensic literature and training slides (Moon; Rosen/NAERMC) repeatedly show pressed‑wood cabinets swell irreversibly and are not restorable by drying.

Procedure (cabinet zones)

1. Remove shoe/base and toe‑kicks to expose the void; photo‑document standing water, silt, and microbial growth.
2. Probe with a pin meter and borescope the wall base, cabinet substrate, and adjacent framing; log cavity MC and RH.
3. If any swelling/delamination/visible growth is present or cavities cannot be cleaned and verified dry, remove affected cabinets; perform source removal (debris extraction, HEPA vacuum, detergent cleaning), then dry framing to target MCs and re‑build.
4. Contain and use negative pressure if growth is present; avoid pressurizing hidden voids with air movers unless cavities are clean and contained.

Tile, Showers & "Water Under Tile" After Flooding

Mechanisms. Flooding re‑wets slabs and assemblies. Water moves through grout joints and perimeter gaps. As slabs dry, hydrostatic pressure and salt transport can create efflorescence, and pre‑existing voids or poor thin‑set coverage may become failure points. In shower walls and tub decks, tile is vapor‑tight; backer/drywall can remain wet behind.

Manufacturer guidance

• CUSTOM Building Products TB101 discusses assessment of flood‑damaged tile installations including bond testing and replacement where bonds/substrates are compromised.
• ARDEX TB229 (flood immersion) describes how immersion affects tile finishes, adhesives, grout and substrates; ordinary interiors are not pool‑spec systems. Evaluation and selective replacement are often required.

Implication. Where water tracked under tile and direct, verified airflow to backsides cannot be created (tile on slab with cabinets left in place, tiled showers over wet backer), prolonged drying may occur and selective removal is commonly discussed to prevent latent failures.

The "2‑Foot Flood Cut … Except Behind Cabinets"

Cutting drywall to 2′ on all walls except behind expensive cabinets and tile is frequently described as a shortcut rather than a standard. If the wall base is wet/contaminated, access is often expected to be consistent—including behind cabinets/tile—to remove wet insulation, clean cavities, and dry framing.

Why Moisture Readings Look "Normal" at Cabinet Faces but High Elsewhere

• Access bias: Non‑invasive (pinless) meters read the top few millimeters and require flat contact. They cannot see into toe‑kicks or to the backside of a cabinet or tiled wall.
• Depth limits: Common pinless meters read ±⅝–¾″; cavity moisture behind tile/cabinet backs is missed unless deep wall probes are used.
• Equilibrium effect: The exposed face equilibrates first; concealed surfaces can remain wet for days or weeks.

Practice note: Use pin meters with extended probes, borescope imaging, and cavity RH/MC targets. Photo‑document each cavity reading and location.

Insurer‑Vendor Conflicts & Common Shortcuts

Field Checklists

Sample Language (paste into reports/letters)

Cabinets.

"Kitchen and bath cabinets (pressed‑wood/MDF) were wetted by the loss. Visible swelling and delamination are present at the gables/toe‑kicks, and hidden voids showed free water and debris. Under the ANSI/IICRC S500 standard of care and published training materials, pressed‑wood cabinets that are swollen are not restorable by drying. The proper course is removal and replacement of affected cabinetry, opening the wall base to remove wet insulation, HEPA clean cavities, and dry framing to target moisture content. Blowing air into closed toe‑kick voids would risk dispersing contamination and does not verify dry standard."

Tile on slab (flood).

"Floodwater re‑wetted the slab and tile assembly. Manufacturer bulletins (e.g., CUSTOM TB101; ARDEX TB229) specify evaluation and bond testing and replacement where bonds/substrates are compromised. Given observed efflorescence, hollow‑sounding tile, and elevated slab moisture, selective tile removal, substrate cleaning, and controlled drying are required prior to re‑installation."

Moisture‑meter limitation.

"Surface moisture readings at cabinet faces appear 'normal' because meters read only accessible surfaces; concealed cavity faces remain wet. Consistent with instrument limitations, cavity probe readings and borescope images are required to verify dry standard."

References & Links (source list)

Notes for claims use

• Place the cabinet photos (swelling/delam) and cavity probe logs adjacent to the S500/BSI/National Flood School citations.
• For tile, include TB101/TB229 links directly under your bond tests and efflorescence photos.
• Quote actions (open, remove, replace, verify dry standard) rather than long standard excerpts, then include the link.

Sister Sites

Help Us Improve This Report

We welcome critiques, counter‑examples, and suggestions. Contact us at (407) 584‑7789 or flatfeeappraisal@gmail.com.

Disclaimer

This site is general information about the appraisal and remediation process and does not constitute legal advice. Policies and laws vary by jurisdiction.