Lower-Level Moisture Control in Milwaukee, WI

Why a slab holds water

A concrete slab can hold water after the surface has dried, and the moisture moves up slowly.

Concrete is porous, and water that has stood on a slab or soaked into it can take a long time to leave. The surface may feel dry while the slab beneath holds moisture. A floor covering laid over a damp slab can trap that moisture and cause problems later.

The crew reads the slab at several points and sets the target from those readings, so the covering is not laid on a slab that is still holding water.

Reading the foundation wall

The foundation wall at the edge is read at the base and at its wicking height, and the readings show how far moisture has risen.

Water drawn up a foundation wall leaves a line at the height it reached. The crew reads the wall at the base, at the line and above it, and records each value. The readings show whether the wall is still wicking or has dried.

A wall that is still wet at its base is a sign that the source or the ground moisture is still active, and the crew notes it in the scope.

• Read the wall at its base
• Read at the wicking line and above it
• Record each value with its height
• Note whether the wall is still wicking
• Note any active ground moisture

Ventilation and the closed room

A lower room that is closed and not ventilated holds moisture, so the air is managed while the work runs.

A closed lower room with no air movement holds moisture in the air and in the materials. The crew sets air movement and dehumidification for the room and records the room's humidity on each visit.

The homeowner should not close the room or seal the vents while the drying runs, unless the crew asks for it.

• Set air movement for the room
• Record humidity on each visit
• Keep vents open unless the crew says otherwise
• Do not seal the room while drying runs
• Confirm the room is ready before closing

Confirming the room is ready

The room is ready when the slab, walls and air reach target, and the confirmation is written before any covering is laid.

The room is confirmed ready when every reading reaches the target in the scope. The confirmation is written, dated and given to the homeowner and to any flooring trade that will lay a covering.

A covering laid before the confirmation can trap moisture and fail, so the homeowner should wait for the written confirmation.

• Every reading reaches the target
• The confirmation is written and dated
• A copy is given to the homeowner
• A copy is given to the flooring trade
• No covering is laid before the confirmation

Dehumidification and the length of the drying

Dehumidification runs for as long as the readings require, and the homeowner is told the expected length.

A slab that holds moisture can take weeks to reach target, and the dehumidifier runs for that whole period. The crew sets the expected length of the drying in the scope and reviews it on each visit. A homeowner who is told the length in advance can plan for the room to be out of use.

The dehumidifier's run time and its readings are recorded, so the drying can be checked against the plan.

A slab that is still moist at the end of the expected period is re-tested, and the crew says whether the plan needs a longer run or a different air set-up.

A slab that dries to target on one visit is re-read on the next, because moisture can rise again from below. Only after two readings at target does the crew confirm the room is ready for a new floor covering, and that confirmation is written.

On arrival the crew checks the address, the power and the source against the notes from the call, then starts the readings. A homeowner who has the notes, the photographs and the shut-off location ready shortens the first visit and keeps the scope accurate.

• The expected length of drying in the scope
• Dehumidifier run time recorded on each visit
• Readings compared with the plan
• The room kept out of use until the target is met
• The homeowner told when the room can be used