Technical Research on Dampness and Materials

What Do We Research and Why?

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Core Conservation has been involved in technical research on dampness, rising damp, lime plasters and various building materials for several years now.

Why Did We Engage In Research?

Here is a bit of background to the story.

We started our activity back in 2013. After surveying a few thousand old buildings for dampness, having in-depth discussions with many building professionals and old building owners alike, we discovered that a lot of commonly-known information on the subject of dampness is incorrect, inaccurate or opinion based, leading to incorrect solutions that can damage old buildings.

Being a team of engineers and scientists, we decided to start a formal research program to validate some of our initial observations while challenging some common misconceptions. These findings led us into the unchartered territory of surface phenomena in damp brickwork, a largely unknown topic even amongst building professionals, which seems to have a very important role in the movement of moisture inside porous materials.

What Do We Research

Our initial research was centered around rising damp, the most complex water transport mechanism Then over time our research has broadened as the topic of moisture movement in old buildings can be influenced by many factors - some known, some less known - which all needed to be taken into consideration. These include the effect of salts, underlying surface- and molecular phenomena, properties of various plasters, electrical effects from the environment and others.

Thus, our research covers the following areas:

Moisture transport in porous building materials: underlying mechanisms and phenomena influencing it: physical, chemical, electrical, magnetic etc.
The role and movement of vapours: as the air around us contains lots of vapours and we are permanently surrounded by it, vapours play a very important role in the wetting-drying phenomena.
Surface phenomena: moisture accumulation and evaporation is not only affected by environmental factors but also my low-level molecular phenomena which plays a very important role in the interaction of water with the masonry surfaces.
Rising damp: underlying mechanisms, influencing factors and building-friendly applications to overcome it, being one of the major problems affecting old buildings.
Aging and damage of traditional building materials by moisture and salts and the underlying mechanisms.
The impact of other building materials onto the damp wall fabric: the effect of lime, gypsum and cement plasters, non-breathable materials etc.

Research Concept

Currently we operate two labs for:

1. Smaller Proof of Concept Projects

We have a separate lab in a controlled environment for small-scale proof-of-concept projects.

For precision measurements we use a Keithley/Tektronix datalogger collecting real-time data on 40 channels, with the capability to double that output for larger, more complex projects.

Some of the parameters we collect and analyze include:

Temperature and humidity of the ambient conditions
Temperature and humidity on the surface of the bricks
Temperature and humidity inside the bricks
Temperature and humidity of the soil and the mortar bed
Gravimetric (drilled core sampling) humidity readings
Pressure readings of the ambient and from the mortar bed
Voltage and current readings at multiple points
Resistance readings
Capacitance and charge movement measurements
High-resolution magnetic readings along 3 axis
... and more

Depending on what we investigate - short transient or slowly-occurring long-term phenomena - we log the data in real time from 1 microsecond (at a rate of 1 million readings per second) to one reading every hour. This also determines the duration of a project, which can vary from minutes or hours to days, weeks or months when monitoring slow long-term changes.

This setup allows us to very accurately pinpoint all important phenomena, track the movement of moisture inside the bricks, in and out of bricks, through the mortar bed, inspect the effect of various parameters from the environment - cross-reference all data streams later on a PC so we can draw accurate conclusions.

C-and-W-sensors-resp-same-freq-34-4-Mhz-core-conservation — Tracking various parameters in the brickwork long-term

2. Larger Scale Tests

Our second lab is for larger scale tests in a natural but protected environment, where we build and test larger walls in different real-life scenarios. Here we can analyze the long-term effect of various type of plasters, breathability, thermal variations, frost damage etc.

Key parameters are also logged by embedded micro-sensors for further analysis.

sensors-core-conservation — Testing the behaviour of various types of plasters

3. Tests on Real Buildings

Finally, some of the concepts are also checked on real buildings. This allows us not only to validate the key concepts in a real-world environment, but also to understand the differences between lab simulations and real buildings, understanding what variables present in nature are difficult or impossible to be simulated in the lab.

IMG_20210529_121234-A1400x787-core-conservation — Research on moisture movement on a real building

Here are some other related pages that you might want to read to broaden your knowledge in this field.

Building Monitoring Systems

Data Logging & Long-Term Monitoring

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Published Research Papers

Our Publications & Papers

Photo Galleries

Here are some photos demonstrating these concepts. Click on any image to open the photo gallery.

Research - Fresh vs Saline Water Wetting

Here we can see the effect of salts, and the difference between fresh water and saline water wetting.

Research - Masonry Drying & Evaporation

Here is the technical experimental setup that we used to record and monitor some of the phenomena that takes place during the long-term slow drying of the masonry capturing tiny changes during the of moisture.

Research - Magnetic DPC Performance

A magnetic DPC system has been installed in the crypt of a large church along with comprehensive research equipment, taking consecutive readings from the depth and surface of the walls, as well as the environment.