Why does hardwood cup after a water loss?
Hardwood cups when the underside of a board is wetter than the top. The wood swells on the wet side and the board bows upward at the edges. It is a sign that moisture is uneven in the floor, and it is reversed only when the moisture in the subfloor and the underside is brought down to match the top.
Cupping can begin within a day or two of water reaching the subfloor, and it can become more pronounced as the wood dries from the top first. A board that has cupped may flatten as the moisture evens out, but a board that has been wet for a long time can be permanently distorted.
The crew does not predict the outcome from the look of the floor. It measures the boards, the underside and the subfloor, and it notes whether the cupping is still increasing. The decision to keep or replace the boards is made when the readings show the wood has stopped changing.
Can carpet be dried in place without being lifted?
Rarely. The pad holds water beneath the surface, and a carpet that is dried on top leaves the pad and subfloor wet. Lifting the carpet is the only reliable way to measure and dry the pad and the floor beneath it, and it is done early before the wet pad causes damage.
A light spill that is wiped up within minutes and does not reach the pad may not need lifting. Anything that has soaked through, or that has been wet for more than a short time, is lifted and assessed.
When a carpet is lifted, the crew stacks and records it so that it can be re-laid if it dries well. Carpet that has been wet with sewage or with floodwater is treated under the sewage or flood steps, and the carpet is removed rather than cleaned.
How do I know whether the subfloor is dry enough to close up?
The subfloor is dry when its moisture reading is at the dry reference taken from an undamaged part of the same floor. A surface that looks dry is not a reliable sign, because the subfloor can hold water below the surface for much longer than the room appears wet.
The crew reads the subfloor from above through small openings and, where needed, from below through the crawl space or the cellar. The readings are logged against the floor plan, so that every area that was wet is shown as dry before it is closed.
Closing a floor too early traps moisture under the new covering, and the problem appears weeks later as a stain, a smell or a lifting board. The crew does not sign off a floor until every reading is at the reference.
What should I expect if the floor is replaced rather than dried?
If a floor must be replaced, the crew says which boards, pad or underlay are removed and why. The subfloor is dried and checked before the new floor is laid. The replacement itself is a separate scope and is priced after the drying has been confirmed.
A replacement floor needs a dry subfloor to sit on. A new floor laid over a wet subfloor will fail in the same way as the old one, so the crew confirms the drying before the flooring contractor begins.
Keep the samples of the old flooring if the replacement is to match it, and photograph the floor before it is removed. The insurer and the flooring contractor both need to know what was there.
Does the floor type change how long drying takes?
Yes. Carpet over pad, solid hardwood and engineered wood with a plywood core each release water at a different rate. Thick pad and tight boards hold moisture longer, so drying takes longer than it does on a bare tile floor.
The crew sets the drying plan for the floor type it finds, and the readings tell it when the floor is ready. A mixed floor, with carpet in one room and hardwood in another, is measured zone by zone, because each zone dries on its own schedule.
The crew does not commit to a number of days over the phone. It commits to a check on each visit and a written log, and it explains the schedule once the floor has been measured.