Moisture readings in concrete walls

nm6

Hi,
I'm looking for information on what normal moisture readings should be for internal concrete walls, floors and plasterboard walls?
I have been getting random smells of damp from time to time, so I got a handheld moisture meter to take some readings.
The moisture meter can take readings via pins or a contact sensor on the back and gives a read out in %.

Does anyone know what percentage is considered a normal reading and what percentage would indicate i might have a problem?
I've checked the attic and vents. No issues that I can see.
Any help appreciated.
Thanks in advance.

Calahonda52

It would be useful to say what numbers you have got.
The other thing is some detail on the gaff, is it a house or farm building or workshop or office or what??
How is it heated?\is it occupied, by how many persons/ what is the ventilation strategy/ what is the moisture vapour load from what sources?
what is the age of the gaff/what is is built from etc

nm6

Calahonda52 wrote: »

It would be useful to say what numbers you have got.
The other thing is some detail on the gaff, is it a house or farm building or workshop or office or what??
How is it heated?\is it occupied, by how many persons/ what is the ventilation strategy/ what is the moisture vapour load from what sources?
what is the age of the gaff/what is is built from etc

Ok thanks for the advice.
I'm getting around 11% mostly and 19% in places.
It is a standard detached four bed domestic use house
Built in 2014
Family of four occupied all the time
Standard oil boiler and radiators
Standard fixed vents in all rooms
Built of normal blocks
I dont know what the moisture vapour load is
Thanks

MicktheMan

nm6 wrote: »

Hi,
I'm looking for information on what normal moisture readings should be for internal concrete walls, floors and plasterboard walls?
I have been getting random smells of damp from time to time, so I got a handheld moisture meter to take some readings.
The moisture meter can take readings via pins or a contact sensor on the back and gives a read out in %.

Does anyone know what percentage is considered a normal reading and what percentage would indicate i might have a problem?
I've checked the attic and vents. No issues that I can see.
Any help appreciated.
Thanks in advance.

First off, how is your moisture meter set up do you know, is it % moisture (u) or % water (w).
Are there any scales or tables showing dry to wet for different materials?

Next, except in particular circumstances, mostly moisture meters are used to check relative wetness or dryness and not absolute values. So you use it first in a known problem free area, see what it reads and then move it to the suspected area(s) and note any significant change in reading.

Examples of vapour load are higher than normal occupancy, drying clothes on rads, lots of potted plants, active water leaks, several aquaria i.e. anything with produces and releases water vapour into the internal air.

nm6

MicktheMan wrote: »

First off, how is your moisture meter set up do you know, is it % moisture (u) or % water (w).
Are there any scales or tables showing dry to wet for different materials?

Next, except in particular circumstances, mostly moisture meters are used to check relative wetness or dryness and not absolute values. So you use it first in a known problem free area, see what it reads and then move it to the suspected area(s) and note any significant change in reading.

Examples of vapour load are higher than normal occupancy, drying clothes on rads, lots of potted plants, active water leaks, several aquaria i.e. anything with produces and releases water vapour into the internal air.

Thanks for explaining that..... My meter says it measures % relative moisture. See attached data sheet. There is a Low/Med/High reference.
Most of my readings on the internal plasterboard covering the external walls are 11% which is in the Low range. Then some of the internal concrete walls that are not covered by plasterboard are 19% which is in the Medium range.
There is no drying of clothes in this area, no aquariums, no known leaks, normal occupancy and no signs of condensation.

The Continental Op

Those meters are fairly useless. The moisture on the surface is no indication of the moisture of the material underneath.

Take a cold concrete wall. It could be quite dry inside but any moisture from the house can condense on it giving a high reading on the surface.

Take a look at this https://www.heritage-house.org/damp-and-condensation/the-ping-prong-meter-guilty-of-fraud.html .

Peter Ward is your man for advice on Youtube and this is how he tests for moisture

nm6

The Continental Op wrote: »

Those meters are fairly useless. The moisture on the surface is no indication of the moisture of the material underneath.

Take a cold concrete wall. It could be quite dry inside but any moisture from the house can condense on it giving a high reading on the surface.

Take a look at this https://www.heritage-house.org/damp-and-condensation/the-ping-prong-meter-guilty-of-fraud.html .

Peter Ward is your man for advice on Youtube and this is how he tests for moisture

Thats unreal!
Thanks for the insight. Never would have thought this.