Environmental stabilising

Environmental monitoring may involve monitoring of building fabric, materials and the building environment.

The remote sensing of the moisture content in timber and monitoring of drying provide simple and economical methods of avoiding serious timber decay. These systems are tailor-made to suit a specific building or its parts to accurately determine the source and distribution of moisture within the building fabric, to detect water penetration in critical areas or to monitor drying following building failure, fire or flood. Data from these investigations is used to determine a policy and control the drying out of the building fabric to reduce the risk of future decay after refurbishment.

Remote sensing of moisture content in masonry: these remote sensing systems can also be tailor-made to suit a specific building or its parts. They can be installed in damp masonry or areas likely to be at risk from water penetration, and the data obtained can be used to determine the state of drying out and to take profiles of moisture across a thick wall that may take many months to dry out. Permanently installed systems can act as a warning for future water penetration.

These systems can be simple or complex. In complex remote sensing systems, the resulting data can be transferred to the computer or via a model to a central building management system.

Continuous environmental monitoring: environmental data loggers can be used to undertake diagnostic continuous environmental monitoring. Typically, data loggers have an accuracy of ±0.7°C and ±5.0% RH at an ambient air temperature of 21°C. Data loggers can be set to continuously measure (every 10 minutes) various environmental parameters:

• internal air-monitoring data loggers can be installed to measure air temperature, relative humidity (RH), vapour pressure and dew points; and
• external data loggers can be installed to measure external temperature, relative humidity (RH), vapour pressure and dew points.

A weather station can also be used to undertake diagnostic external environmental monitoring. The weather station consists of a wind monitor and a rain gauge. The wind monitor continuously measures wind speed (accurate to ±0.3ms-1 at 1 to 60ms-1, and ±1.0ms-1 at 60 to 100ms-1) and wind direction (accurate to ±3.0°). The wind direction is measured clockwise from north (0°) back round to north (360°). The rain gauge (accurate to ±0.25mm) continuously measures the rate and total amount of precipitation.