Structural drying that finishes on a timeline, not when the instruments confirm it, leads to mold behind walls and the callbacks that follow. Our Preston drying crew completes the program when the readings say it's done — not before.
The difference between structural drying done right and structural drying done fast is what ends up in your walls three months later.
Low-grain refrigerant (LGR) dehumidifiers operate more efficiently in the low-humidity conditions created by an active drying program than conventional dehumidifiers — achieving lower dewpoint conditions that accelerate evaporation from structural materials. Our Preston structural drying crews deploy properly sized LGR equipment based on the specific volume and material profile of your affected assemblies. Equipment sizing is calculated, not estimated.
Every active drying project in Preston receives a daily psychrometric reading session: temperature, relative humidity, specific humidity, grains per pound of moisture in the air, and moisture content readings at fixed sensor points in each structural assembly. These readings are logged and provided as documentation of the drying program for your insurance claim. Drying is declared complete only when readings at all sensor points fall within the target EMC range for the material species being dried.
Wall cavity drying is where most post-loss mold in Preston properties originates. It's where we focus.
Insurance-formatted drying documentation means faster settlement and fewer adjuster callbacks.
COS Water Damage Restoration's Preston structural drying service covers every assembly type and situation encountered in a water damage event — from standard floor and wall assemblies to hardwood systems, crawlspace framing, and multi-story moisture migration events.
Wall cavity drying in Preston is standard procedure on every job where moisture mapping indicates wall system saturation.
Subfloor assemblies — OSB or plywood sheathing over floor joists — and hardwood flooring systems require targeted drying approaches because of their density and their tendency to cup, buckle, or swell when dried too aggressively or left wet too long. Our Preston drying crew evaluates hardwood flooring species and moisture content before recommending drying-in-place versus removal, and when drying in place is appropriate, we use floor drying mats that direct conditioned air against the top face of the hardwood under controlled pressure — accelerating evaporation while minimizing the differential drying stress that causes cupping.
Crawlspace drying in Preston properties is complicated by limited access, typically poor natural ventilation, and the presence of vapor barriers that may trap moisture against wood framing. Our Preston below-grade drying team is equipped with compact high-velocity air movers that fit through standard crawlspace access hatches, portable LGR units configured for below-grade operation, and moisture meters suitable for sub-surface readings at joist and beam locations. Vapor barrier condition is evaluated and re-secured after drying if disturbed during the process.
Ceiling assembly drying is one of the more technically demanding aspects of water damage restoration in Preston structures.
Large-scale commercial drying in Preston is project-managed from day one with zone-specific reading logs.
Every active structural drying program in Preston is also a mold prevention program — because the conditions that support mold growth (elevated moisture content in organic materials and elevated relative humidity in the air space) are exactly the conditions a drying program is designed to eliminate. Our daily reading sessions include assessment of the ambient RH and temperature conditions in each drying zone against the threshold conditions that support mold colonization. If readings suggest an elevated mold risk — particularly in projects where extraction was delayed — we address it proactively with targeted antimicrobial treatment during the active drying program.


Before one piece of drying equipment is placed, our Preston team completes a full moisture mapping session using FLIR thermal imaging and calibrated pin-type and non-penetrating meters. The map documents all affected assemblies, saturation levels, and the extent of moisture migration through the structure. Equipment placement and sizing are calculated from this map.
Equipment placement is engineered based on the moisture map and assembly data — not placed by habit.
Every calendar day, our Preston technician visits your property, takes complete psychrometric readings at all sensor points and ambient measurement locations, logs the data, adjusts equipment if indicated, and reports the daily progress to you and your insurance carrier. The drying program continues until all assemblies reach their EMC target range.
When all sensor point readings fall within the target equilibrium moisture content range for the specific materials being dried, we perform a final comprehensive moisture survey of the entire affected area and issue a written drying completion report. This report is included in your insurance claim documentation and serves as your record of successful structural drying.



"We'd had a water damage company dry our house after a previous event and they removed equipment on day 5 and called it done. Three months later, mold behind the walls. This time I specifically chose COS Water Damage Restoration because of their documentation process. Daily readings, specific sensor point data, instrument-confirmed completion. No mold, no callbacks, no repeat of the last time."
"Our insurance adjuster was skeptical about the drying scope initially, but COS Water Damage Restoration's documentation — the daily moisture logs, the floor plan with sensor point locations, the before and after readings — was thorough enough that the adjuster approved the full scope without any back-and-forth. That documentation is worth its weight in the claim settlement alone."
"We had a particularly complex drying project across three floors of a Preston office building after an upstairs pipe event. COS Water Damage Restoration managed the zone readings, adjusted equipment as the drying progressed on different floors at different rates, and wrapped the entire building within 11 days with full documentation. That's professional-grade project management."
COS Water Damage Restoration's Preston structural drying team serves Preston and surrounding communities throughout IA. Daily monitoring included. Call +1-844-499-0972 to get started.
Don't let wet wall cavities become next month's mold problem. Call +1-844-499-0972 and get Preston's certified structural drying team on site.
📞 Call +1-844-499-0972 — Preston Structural Drying24/7 Available · IICRC WRT Certified · Daily Readings · Preston, IA