Acceptable Moisture Levels In Plaster Walls

Zero moisture is unrealistic even wood used to frame a house contains some amount of moisture.

Acceptable moisture levels in plaster walls.

And while these walls are built to be water repellant excessive water exposure over time can lead to moisture retention. Compare the reading to ideal moisture levels. Exterior walls are regularly exposed to moisture. Anything above 1 mc in drywall would indicate a level of moisture that could compromise the integrity of the gypsum board.

There is no acceptable level of damp in plaster if you can see it or feel it with the back of your hand in your case as perry said give it more time to dry out keep the room on low heating and maintain ventilation. In severe conditions you may see higher readings of skirting 22 plaster 1 3 and brick around 2 5. Example a timber skirting which records a moisture reading of 12 air dry the plaster could be around 0 5 and the brick about 1. Calm down 20 24 in plaster is not a problem.

Any reading over 17 percent is considered to be an indication of saturation and the need to replace the drywall and to take preventative measures against future moisture buildup. A reading of up to 17 percent is generally considered moderate moisture and acceptable. Generally speaking for drywall a safe moisture content mc would be less than 1 mc. The actual threshold depends on the length of time the high level of moisture has persisted the source and even the type of paint or coating used on the gypsum boards.

Normal readings measure between 7 and 13 percent. The human hand is not able to detect moisture anywhere near the 15 threshold. Readings over that indicate the likelihood of some free water but if there is really quite a lot of water say 35 or 60 showing on the meter for example then this needs investigating. However older buildings may use other interior wall surfaces such as wooden paneling or plaster.

It is crucial not to quote these percentages as a moisture content of a wall.