Understanding Water Damage – Drying a Building

It is almost impossible to provide a fixed methodology that governs how a water damage contractor can set about drying a building following an escape of water. Due to the sheer magnitude of different building constructions that span several hundred years of innovation, the best advice that we can offer is what most would perceive to be best practice and guidance. It is the responsibility of a water damage technician to survey the area, determine the most appropriate drying solution to be deployed, and to then measure, document, analyse and review the drying progress that is being made, and adapt to the challenges that present themselves.

  1. Moisture Measurement/Mapping – this is by far the most critical stage of the drying process as you cannot successfully remediate an escape of water until you have fully analysed and documented the extent to which the property is damaged and the severity of the damage. It is not uncommon for a contractor to visit a property to inspect signs of water damage in a customer’s lounge only to find that the root cause of the damage is a leaking pipe in the kitchen. Effective moisture mapping not only ensures that you have accurate documentation to track the progress of your drying, but it also ensures that you are drying all affected areas and not just those highlighted by the customer. This is the first opportunity for the contractor to determine the construction type, the layers of insulation materials contained within it, and the time for them to start considering the most appropriate method of drying (e.g. condensation dryers, adsorption dryers, pressure/suction drying, heat).​
  2. Stabilization Phase – The stabilization phase of a water damage has a primary aim of minimising the risk of secondary damage occurring on the claim whilst other works such as strip-out, further surveying of the area, asbestos checks, and arrangement of alternative accommodation take place. The stabilization phase typically involves the placement of a condensing dehumidifier, and often additional air movement, in the property to reduce the specific humidity of the air and keep the %RH below the threshold where condensation forms on surfaces and mould growth can become an issue (typically >60%RH). During the stabilization phase of drying, it is not uncommon to see contractors install air filtration devices (AFDs) to help minimise the amount of contamination in the living space, such as dust, dirt, or mould spores. These systems can be fitted with a range of filtration media such as F9 (Dust), H13 (Mould), or even H14 (Virus).
  3. Structural Drying Phase – During the stabilization phase, the ambient air in the living space is already being dried, reducing its vapour pressure, which in turn supports the efficient drying of the wet surfaces of the materials and allows them to start releasing water into the drying environment. The structural drying phase of restoration is where the contractor predominantly focuses on the building materials themselves, rather than just drying the air in the room. During this phase the technician will be re-taking measurements such as surface temperature, WME (Wood Moisture Equivalent), in-depth humidity, and REL (Relative Scale) to make comparisons against their initial moisture mapping and determine the worst affected areas. Now is the time for the technician to modify their set up and introduce a drying methodology to focus on these areas:​
  • Condensation Drying and Air Movement – This is by far the most common approach to drying simple constructions such as plasterboard walls and ceilings, lightweight concrete blocks, and exposed wood framing. The condensation dryer will remove moisture from the ambient air, reducing the vapour pressure of the air and creating an environment which helps promote evaporation of water from the structural building materials. ​Air movement is used to break the surface tension and lift the water vapour that sits on the surface of the material into the air, where it can be collected by the condensation dryer. When installed correctly, a drying system based around condensation drying technology can be incredibly energy-efficient and effective. One common issue relating to this type of drying is when the equipment is deployed in an environment that is a) too cold for evaporation to take place in the materials, and b) equipment is deployed in an ineffective manner. Some condensing dryers offer features such as additional heaters (~1kW) and high-pressure fans which can help elevate the temperatures of the materials being dried and speed up the drying process.
  • Adsorption Drying – Adsorption dryers are designed to produce incredibly dry air and can reach low %RH levels (<10%RH) that are beyond the capabilities of a traditional condensation dryer (normally 25-30%RH). The way that they achieve this is by passing the ambient air through an adsorption media (typically a silica rotor) rather than passing wet air over cold coils. The production of this incredibly dry air through the adsorption system means that the vapour pressure of the process air is much lower than you would ever achieve when using a condensation dryer – this super-dry air is commonly used to dry more difficult to dry building materials like hardwoods, dense concrete, and insulation materials. An adsorption dryer would normally be ducted into plastic containment or targeted into a cavity using a side-channel blower or turbine. A limitation of an adsorption system is that they use approx. twice the amount of energy as a condensation dryer (litres/kW) and typically have lower airflows (m3/hr). They also require venting externally from the building as they produce hot, wet exhaust air.
  • Pressure/Suction Drying – As building constructions have evolved to become eco-friendlier and more sustainable, the way in which the buildings can be dried following an escape of water has become far more complex. To overcome the challenges presented by multi-layered building constructions that include non-permeable membranes, open/closed cell insultation, and vapour retardant special coatings, manufacturers have developed positive and negative pressure drying solutions to help guide the process air from a dehumidifier to the hidden wet areas. The Aerial AERCUBE system provides innovation in the area of positive and negative pressure drying systems, giving technicians a modular system that can be configured in a number of ways to deliver the solution they require for each individual claim. ​
  • Heat DryingHeat drying is a relatively new concept within the world of water damage restoration despite the common acceptance that heat energy is one of the key driving factors behind an effective drying program. Targeted heat drying plays a crucial role in the process when air temperatures and surface temperatures of materials are low, and contractors do not have access to the properties normal central heating systems to rectify this issue. Additionally, they provide a way of focusing high amounts of energy and air flow directly onto, or within, a construction that is severely affected by water ingress. The ability to deploy controlled levels of heat in a targeted way is a valuable tool for any restorer.
    1. Remote MonitoringRemote monitoring of a drying process is proven to remove and reduce costs associated with the management of a water damage claim. Firstly, the ability to remotely monitor the drying process gives technicians the capability to respond quickly to unpredicted events, such as equipment being switched off or simply not performing as expected. This speed of response reduces downtime and subsequently reduces the negative impact on the claim life cycle. The ability to remotely track progress of a claim also means that time isn’t wasted, with equipment being decommissioned as soon as possible so that it can be redeployed on other cases, rather than sitting in a job for an extra week unnecessarily. Then you consider the cost savings associated with minimising the number of site visits made by a technician, their time (labour cost), their travel (travel costs), and the lost productivity of them being unavailable to attend other cases.​

    Summary – No matter what suppliers may tell you, there is no one-size-fits-all approach or solution to water damage. The reason why Dantherm Group offers such as diverse portfolio of drying solutions is because we recognize and support the need of water damage technicians to have a wide array of tools in their toolbox.

    Feel free to contact us to find out more about what we can do to support you!

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    Dantherm Group UK

    Alan James

    Business Development Manager
    Mobile:+44 (0)7761 514 079

    Contact Alan

    General Enquiries

    +44 (0)1621 856 611

    sales.uk@dantherm.com


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