Problem: Wavy ceilings.
Cause: Excess humidity in the house during construction.
High humidity during construction can cause the drywall to take on extra moisture. Construction humidity comes from drying lumber, interior finishing materials, temporary heat (propane) and poured concrete floors.
Solutions: Properly schedule activities to reduce the amount of humidity present after you have installed the drywall, and ventilate to keep moisture levels low.
- Insulate the ceiling immediately after installing the ceiling drywall. Condensation can occur on the upper side of the ceiling drywall during cool or cold weather if the attic is not insulated promptly after the ceiling drywall is installed. Moisture form inside the house will freeze or condense on the vapor barrier above the ceiling drywall. This moisture will then be absorbed by the ceiling drywall and cause it to sag.
- Schedule work in the house so that you reduce the amount of moisture present after the drywall is installed. The pouring of concrete floors and other similar activities can introduce large amounts of moisture, which can be absorbed by the drywall and cause it to sag. Do all of these types of activities before you drywall.
- Providing plenty of ventilation during construction is critical to keeping humidity levels under control. Literally thousands of gallons of water can be introduced into the house from construction materials and temporary unvented heaters. Some of this moisture will be absorbed by the drywall unless the house is continuously ventilated to reduce moisture levels.
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