Best Conditions for Internal Thermal Inspection
The optimum conditions for carrying out an Internal Infrared snagging survey of your new build home are as follows
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- Turn up your heating – ideal conditions are a minimum of 10 degrees temperature difference between inside and outside air temperatures, this environment gives the most accurate thermal images for analysis and thermal tuning.
- Turn off any fans and artificial sources of air circulation (unless using Air Testing conditions).
- Furniture should be moved away from external walls prior to the survey with enough time to allow the temperature to normalise across the areas exposed.
- External surfaces should be free of moisture (no rain for at least 36 hours prior to survey).
- External wind speed should be less than 5m/s.
- The exterior of the building should be free of solar radiation.
As with all thermal envelope surveys, according to the standards set out in BS EN 13187, the required conditions for carrying out the inspection are a minimum 10° C difference between the internal and external ambient temperature. The easiest way to achieve this in the UK is to turn the heating up inside the home and carry out the inspection 2-3 hours after sunset (in order to mitigate for the next factor).
Reduce the effects of the Sun – Solar Gain
During daylight hours, the effects of solar gain can greatly skew any results gathered during a thermal survey so all surveys should be carried out once the sun has gone down and the building surface has had a chance to cool down, and the solar gain effects removed. It is often recommended to carry out the survey just prior to sunset to allow the building as much time as possible to reduce the effect of solar gain, however, in the UK this could often mean that the exterior of the building would then be affected by moisture due to condensation as the warm air cools, which would, in turn, affect the survey results as discussed below.
Wind Speed
Wind speed should be 5m/s or less. Higher wind speeds will affect the thermal boundary layer on the building surface creating a cooling effect impacting the survey results.
All surfaces should be dry prior to the survey being carried out and throughout the duration of the survey.
All surfaces should be dry
Prior to the survey being carried out and throughout the duration of the survey, all surfaces to be surveyed should be kept dry. Moisture on the building surface can have a reflective effect and lead to incorrect readings.
Finally, it is important to note that the environmental conditions, as described above, should not vary greatly during the period of the survey being carried out.
While you may see thermal surveys carried out in different conditions elsewhere in the world, with some lucky thermographers even using high external temperatures and lower internal temperatures to create a 10° C difference (air conditioning systems inside buildings on hot days outside), the perfect conditions to carry out an external building thermal survey in the UK would be a cold, dry night with low humidity.
Once images are captured and analysed by our qualified thermographers, we are able to highlight any areas of snagging that are invisible to the naked eye without you having to undertake any invasive work on your property.
Why you should use a Qualified Thermographer
Our thermographers are British Institute of Non-Destructive Testing Level 2 Qualified. This means they have been trained to ensure the correct conditions are met to carry out the inspection and are then able to analyse and comment on the images taken in a report format. Hopefully, your home has been built to give you a high level of thermal comfort but if mistakes have been made in the build process, a thermal survey gives you a chance to identify and rectify these thermal anomalies with your builder. If you are unable to reach an agreement on repairs required, a report issued by a Level 2 qualified thermographer can be used in legal proceedings as supporting evidence to any claim you may have.
Our reports are not just for homeowners, we also work with many housebuilders who will use our service to show that the properties they have built are up to the standards that they set.
Who is a Thermal Snagging Survey useful for?
Whether you are a new build property purchaser for your own home or a property investor you should carefully consider a nondestructive thermal survey. New build properties can cost from £100K to £1Million+ and unless you built the property yourself, without extensive invasive works, you would never be able to find out whether any faults were created during the build process.
According to a report by the House Builders Federation (HBF) and NHBC, 42% of new home purchasers had reported more than 10 problems to their builder.
As your home is one of the most expensive items you will likely purchase in your lifetime, it is strange that it is also one of the least protected by law with property purchases being exempt from the Sale and Supply of Goods Act.
Most warranty providers work on the premise that most defects are covered in the first two years, but the years 3 to 10 of the warranty period moves to major structural and weatherproofing defects only. Every warranty is different so you should read your policy to understand what you are covered for.
