Checking For Damp Within A Building

Introduction
This article highlights basic understanding of moisture and provides techniques to look for damp and how to use a digital moisture meter to diagnose moisture levels. Due to the comprehensive nature of the subject, we have segmented down the original article into bight size subjects.

1. What Is Damp?
2. Difference in damp of materials
3. How To Pinpoint Moisture within a Structure
4. Measuring Moisture
5. How To Check For Condensation 

1. What Is Damp?
Damp is caused by water getting into the property (structural) and moisture building up within the property causing condensation (lifestyle).

a. Damp ingress into a property (Structural)
Damp occurs when water penetrates into the fabric of a building. Common causes are:

• Rainwater seeping through the roof where a tile or slate is missing, spilling from a blocked gutter or penetrating around window frames.
• Rising damp due to a defective damp-course or because there is no damp-course.
• Leaking pipes, wastes or overflows. Often you can see damp as “tide marks” on walls and ceilings.

b. Condensation (Lifestyle)
Lifestyle moisture issues are caused by normal daily activities (taking showers and baths, washing and drying clothes, cooking and boiling kettles), all produce warm air containing large amounts of water vapour.

If the warm air can’t escape through an open window or air vent, it moves around until it finds a cold surface where it cools and forms condensation.

Condensation occurs on any cold surface which records a below dew point temperature (temperature at which saturated air releases surplus moisture vapour). This can be seen on a mirror in a bathroom or a window in a kitchen when cooking.

2. Difference in damp of materials
Building materials will absorb different levels of moisture content, some materials, like wood, can absorb more water than brick.

Commonly timber will absorb more water molecules than a brick wall. Wood is like a sponge, absorbing moisture directly from the buildings structure and retain higher levels of moisture before directly being affected by the damp process.

The follow table provides examples showing the percentage moisture and the readings interpretation.

Material	Moisture content %	Interpretation
Wood	Extremely dry
Mortar	4	Dry
Brick	4	Damp
Plaster	4	Very wet
Wood	12	Air dry
Brick	12	Saturated
Plaster	12	Not possible

As shown, wood can be classed as dry at 12%, but brick would be saturated at the same reading.

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%. In severe conditions you may see higher readings of skirting 22%, plaster 1% - 3% and brick around 2% - 5%.

Readings are taken on a reference scale as it is only a relative degree of dampness. Wood moisture scale (wood moisture equivalent ‘WME’) is the most common and is recognised by professional bodies. Wood is the first material to degrade due to damp.

How To Pinpoint Moisture within a Structure

First conduct a visual check to review the property for any signs of visible moisture damage. When verifying the buildings moisture condition, look for discolouration first. This will allow you to target the affected areas first.

Pinpointing the damp is only possibly with an electronic moisture meter. These instruments can detect moisture levels before they become visible or can be felt.

When measuring moisture, take regular readings over the suspected area and mark the boundaries of moisture levels. Develop a scaled drawing of the moisture readings recording the levels within the affected areas to determine the severity.

Pinpointing Rising Damp

Pinpointing Damp Spots

For a definitive guide into damp, I would recommend the Dampness In Buildings book distributed by Protimeter. This is a comprehensive guide to moisture in buildings and a copy can be purchased directly through our online store.

Click to review previous section - What Is Damp?

Protimeter Surveymaster - Just Got Better!

GE Measurement & Control has launched its powerful new detection instrument, the Protimeter Surveymaster. With dual measuring functions, professionals can assess the moisture conditions with the confidence that the readings are correct every time!

The Protimeter Surveymaster has been the mainstay of professionals for 15 years, providing quick and accurate moisture readings. Its accuracy has been the key factor for this instruments success, providing an instrument that is simple to use but reassuring that the readings are correct.

At the heart of the Protimeter Surveymaster is a newly developed ergonomic case that provides clearer readings and a reassuring grip of the instrument. The instruments larger digital LCD backlit screen, eliminates the moisture readings supported by 60 coloured LEDs depicting the severity of the moisture reading.

The Protimeter Surveymaster can help building professionals—such as contractors, surveyors, home builders and architects—assess building moisture levels during new build and refurbishing activities.

Professionals involved with the identification, management and remedy of moisture need tools that help them to:
• Identify the extent of the moisture penetration
• Diagnose the cause of the problem
• Monitor change in the moisture level

Dual Measuring Modes
Protimeter has pioneered the development of moistures meters, bring to market a range of instruments that are more accurate than their nearest competitors. Part of this development is the combination of dual moisture measuring readings within the Protimeter Surveymaster.

This reliable moisture meter has two modes of operation—search and measure. These functions can help the user to distinguish sub-surface from surface moisture, essential information when trying to establish the extent and cause of a dampness problem.

Search Mode—Non-Invasive
The search mode is used to assess the moisture level beneath the surface of solid walls and floors independently of surface conditions. When held against the surface, the instrument transmits a signal into the material. The relative moisture level is shown on the digital display and its moisture condition is shown on the accompanying scale of color-coded lights.

Measure Mode—Pin-Type
This mode is used to measure the moisture level at the surface. Measure mode readings are precise and specific to the immediate area of contact of the electrodes. The actual moisture content of wood is shown on the digital display with the corresponding moisture condition shown on the accompanying scale of color-coded lights.

Reference mode (Patent Pending)
In both Pin and Search mode, the Protimeter Reference Mode can be useful when trying to establish what materials are above or below a point of reference or dry standard.

Measure the dry standard or baseline material until the meter’s reading is stable then press for seconds. This will store the reading until the mode changes of the meter turns off. Now all readings taken after will be displayed as normal, but below you will see a second reading that shows you if the material is measured above or below the original reading.

Click for more information on the Protimeter Surveymaster2

Protimeter Mini – How To Measure Moisture

The Protimeter Mini moisture meter has been the choice for thousands of users across the world for more than 30 years. The enduring popularity and success of these instruments is attributable to their versatility, simple design, robust construction and ease of use.

Commonly utilised by building surveyors for checking the building structures, the Protimeter Mini can measure both the surface and sub-surface moisture. Featuring two pins at the top of the instrument for reading surface damp readings, whilst deep wall probes can be utilised to measure the sub-surface readings.

Taking the readings
The display is a collection of 60 LEDs divided into color-coded zones signify moisture readings of the material under investigation. The green, yellow, and red color-coded zones indicate the following:
• Material in the green zone is in a safe air-dry condition.
• In the yellow zone, moisture levels are higher than normal but not critical; further investigation is recommended.
• The red zone represents excessive moisture levels. If sustained, red zone moisture levels will lead to decay in organic materials.

When reading off the damp measurement, the scale runs from 6% to 90% WMC (wood moisture content). Depending upon the moisture reading, one of the LEDs will light up allowing the surveyor to read of the moisture reading.

The WME value is the theoretical moisture level that would be attained by wood that is in moisture equilibrium with the material being tested.

Surface Readings
Simply hold the instrument with the pins touching the material’s surface and read the moisture level from the LED scale.

A low or no reading will occur if the pins are placed onto a painted or varnished surface. Similarly a covering like vinyl will not hold moisture and provide a low reading.

Be careful not to push the pins into a surface which can be damaged or marked.

Sub-Surface Readings
When determining the sub-surface moisture readings, the surveyors can utilise a set of deep wall probes which connect to the Protimeter Mini through the external auxiliary port.

To use the Deep Wall Probe, drill two clearance holes 1/4 in. (6 mm) in diameter and approximately 1 1/2 in. (40 mm) apart to the required depth.

Connect the Deep Wall Probes to the instrument and push the two probe rods into the clearance holes. Hold the rods firmly against the base of the holes while taking the reading (see photograph at right).



If you would like to read the full operators instructions, please follow this link

If you would like to read more information on the Protimeter Mini, please follow this link

How To Detect Moisture In A Building

Detecting moisture in buildings is relatively simple with the right instrument and following the correct procedure.

There are multiple reasons why moisture can enter a building structure, but for the purpose of this article we will look at how to detect moisture using electronic equipment.

But what is moisture?
Moisture can be found throughout the building structure in differing levels and can fluctuate throughout the year. For most of the time, this will be minor atmospheric moisture absorbed by the building material or covering (wall paper and flooring).

However, moisture is a hazard long before you see it and will not become visibly damp until it is too late. Degradation of the material will start before it can be detected with human senses like touch.

Building materials are like sponges, featuring a porous structure which absorbs water. If water enters a property, it can travel for the primary source to a secondary material. This ‘diffusion’ drives the mositure to dry areas and eventually the surface where you would normally encounter a problem.

Surface moisture can dry through evaporation caused by air movement. But in most cases the surface has a covering (wall paper, paint or wood flooring) which acts as a barrier stopping evaporation. Initially you will not encounter a problem until the moisture level reaches a point that causes the covering to lift, peel or crack.
When undertaking an inspection of a property, a good surveyor should check both the surface and sub-surface moisture levels. This will ensure that any potential problems are spotted before it’s too late.

How to detect moisture
When undertaking a moisture reading of a building structure, there are three test that can be performed; surface moisture reading, sub-surface moisture reading and humidity.

Protimeter Mini taking a reading with pins

1. Surface Moisture Readings
Measuring the surface moisture is a relatively simple process utilising a pin type electronic moisture reading device.

Both the Protimeter Mini and Protimeter Surveymaster incorporate two metal pins at the top of the instrument. By placing these pins on the surface, the instrument reads the moisture levels between the pins. Higher the water level will generate a higher moisture reading.

The readings are displayed through a simple coloured LEDs. Green for good, yellow for borderline and red for bad. So simply, if the reading is in the green the moisture level is at a 'no risk' level.

If the reading displays a yellow LED, the surveyor should determine if further inspection of the building structure should be undertaken. If the reading is in the red, the moisture level is too high and the surveyor should undertake a further assessment.

With the Protimeter Surveymaster, the readings are supported with a LCD display providing a digital reading of the moisture level.


2. Sub-surface Moisture Readings
Sub surface readings are an important indication of the moisture condition of the building structure. More moisture will be locked inside the building material than on the surface.

Protmeter Surveymaster using the search mode

Non-invasive
Protimeter has developed a non-invasive search mode which penetrates to a depth of 20mm. The return signal will be displayed digitally through a simple LCD display between 0 to 1000 REL. The REL stands for relative reading and is an indication of the moisture level.

Again a simple LED display employed to provide a quick determination of the reading. If the moisture level is too high, a further invasive test should be undertaken.

Both the Protimeter Aquant and Protimeter Surveymaster are equipment with this method of moisture detection.

Protimeter Mini using deep wall probes for electrical conductivity test

Electrical Conductivity
One further method for measuring sub-surface moisture is to drill two holes and pass a deep wall probe into the wall. The moisture readings are measured by the electrical conductivity through the material. Higher the reading the larger amount of water is present. This provides an important additional check to determine the extent of moisture in a material like a wall or concrete structure.

This can be undertaken with the Protimeter Mini, Protimeter Surveymaster and Protimeter MMS2 models.

Protimeter MMS undertaking a humidity and condensation test

3. Humidity Test
Commonly within a property a high level of humidity will be generated through general living conditions. Either through cooking, taking a shower or even breathing, moisture will be released into the environment.

Without proper air circulation, the first thing you may see is condensation on windows or tiles. In server conditions, wall paper will start to peel off and mould will grow.

By utilising a Protimeter Hygromaster, Protimeter Pysclone or Protmeter MMS2, the surveyor will be able to take a digital reading of the humidity levels.

All readings are displayed as a %RH (Relative Humidity) supported with either a temperature reading or dew point reading.

If the reading is above 70%RH, the moisture levels within the environment are high enough for bacteria to grow. It’s the bacteria that breaks down the building materials and causes damage.

With the Protimeter MMS2, a condensation test can be performed. This runs through the relevant moisture and temperature readings to determine if there is a condensation issue.


Further Reading

If you would like more information on moisture
Dampness Measurement in Concrete Floors
How to Measure Moisture in Buildings


If you would like more information on the Protimeter range, please visit www.damp-meter-direct.co.uk
Protimeter Mini
Protimeter Aquant
Protimeter Surveymaster
Protimeter Hygomaster
Protimeter Pysclone
Protimeter MMS2

Fugenex Damp Protect

Fugenex Damp Protect is a simple innovative method for measuring humidity through an irreversible humidity indicator.
The Fugenex Damp Protect indicators provide early warning signals of humidity and help to indicated if there is a condensation problem rather than a structural fault.

There are many ways to get an on-the spot account of the relative atmospheric humidity, however, there are few ways of easily measuring the relative humidity over a period of time, i.e. how long something has been exposed to humidity above a certain level.


Fugenex Damp Protect sensors, provide a physical-chemical principle, show how long the relative humidity has exceeded a predetermined level. The reading on the indicator is non-reversible. This means that even if the relative humidity temporarily falls below the humidity level, the maximum humidity reading remains unchanged.

Fugenex sensors have a robust design that assures high reliability. The indicators are easy to read and understand, as the length of the reading is proportional to the time that exposure to humidity has exceeded the predetermined level.

Click for more information - www.surveyexpress.co.uk

Click for information on damp meters - www.damp-meter-direct.co.uk