Wet Carpet and Underpad: What Can Be Saved

With wet carpet after a flood, save or replace comes down to three things: how clean the water was, how long the carpet stayed wet and what condition it was in before. Carpet soaked by clean water and dried within a day or two can usually be saved. The underpad usually cannot, and it is cheap to replace. Carpet and pad wet with sewage or outdoor floodwater both go.

The carpet and the pad are two different questions

Most carpet made in the last few decades is synthetic: nylon, polyester or olefin face fibres on a synthetic backing. Those materials do not rot and they release water fairly easily. With enough air moving over and under it, a wet carpet dries in a day or two.

The underpad is a different material with a different job. It is a thick sheet of foam or fibre built to be soft, which also makes it an excellent sponge. A soaked pad holds many times its weight in water, presses that water against the subfloor and dries very slowly under a carpet. Since pad costs little compared with carpet, the standard approach on a real soak is to remove the pad and dry the carpet.

Wet carpet after a flood: save or replace by water type

Restorers sort water into three groups, and the group decides most of the answer.

• Clean water, such as a burst supply line, a leaking water heater or an overflowing sink with the tap running. Carpet can be saved if drying starts promptly. Pad is dried in place only when it is lightly wet in a small area, and replaced otherwise.
• Grey water, such as a washing machine or dishwasher discharge, or clean water that has sat for a couple of days. The pad is replaced. The carpet can sometimes be saved with thorough cleaning after drying, depending on its condition and how long it sat.
• Sewage and outdoor floodwater, including a floor drain backing up or water coming in over soil. Carpet and pad are both removed and discarded. This water carries bacteria and other contaminants that cannot be reliably cleaned out of soft materials.

Signs the carpet cannot be saved

• The backing is coming apart. Carpet is two layers of backing glued together, and long soaking breaks that glue down. If the layers peel apart at a corner, or the carpet ripples and feels loose, it has delaminated.
• It smells musty or sour after it has dried.
• There is visible mold on the backing or the underside.
• It was wet for more than two or three days.
• It is glued directly to the floor and the water got underneath across a wide area.
• It was near the end of its life anyway. Spending money to save a worn, fifteen-year-old carpet rarely makes sense.

How wet carpet is dried and saved

1. Water is extracted from the carpet with a powerful vacuum. This step removes far more water, far faster, than any amount of evaporation.
2. The carpet is released from the tack strip along one or two walls and folded back.
3. Wet pad is cut out, bagged and removed.
4. The subfloor or concrete underneath is checked with a moisture meter and extracted or mopped as needed.
5. The carpet is laid back down and air movers are set so that air flows both across the top and underneath it, with a dehumidifier running in the room.
6. The carpet, the floor under it and the base of the surrounding walls are read daily until all of them are dry.
7. A carpet installer then lays new pad, re-stretches the carpet onto the tack strips and repairs any seams. A hot-water cleaning afterwards freshens it and removes anything the leak left behind.

Basement carpet over concrete

Much of the carpet we see wet is in finished basements, laid over pad on a concrete slab. Concrete will not be harmed by water, but it holds moisture and releases it slowly, and it stays cool, which slows drying of anything on top. Pad on a basement slab should come out after any real soaking. If the water came up through a floor drain or in through the foundation, treat it as contaminated until someone has identified the source.

What to do before help arrives

• Stop the source and stay out of the water if it has reached outlets or cords.
• Get furniture off the carpet or put foil or plastic under the legs. Wood stain and rusty metal feet leave permanent marks on wet carpet.
• Pick up loose rugs, boxes, books and anything else that can bleed colour.
• Walk on it as little as possible. Wet backing is weak and foot traffic helps it come apart.
• Do not rely on a shop vacuum and a fan for a soaked room. They dry the fibres you can see and leave the pad full.

Peel back one corner of the carpet at a wall if you can do it without force. What the pad looks and feels like under there tells you most of what you need to know.

Common questions