TIEE – Thermal Imaging Energy Efficiency Survey of a Flat Roof on a Sand Stone Indian Temple in Potters Bar EN6The objective was to conduct a qualitative thermographic survey to find the water ingress points on the Indian Temple at EN6.
My briefing consisted of the following information:
- Building has no metal within its construction; mainly sand stone, marble and mortar.
- Triflex roofing membrane with various patches.
- Internal water drainage at 6 points.
- Leaking since first built.
- 4 main points of water ingress
Flat Roof Survey Conditions
- External: 8.20 pm
- Inspection followed dry weather.
- Temperature 10°c
- Humidity 85%
- Internal: No windows open.
- Temperature 23-25°c
- Single room of interest.
For optimum results during the thermal imaging survey, products such as 3m tape were used. These have known emissivity values and are as non reflective as possible; therefore helping control the conditions of the survey. The camera was not always calibrated for each photograph depending on the emissivity of the target surface, and the reflective temperature was not always calculated; these figures were not always used to compensate for any variables.
This was a qualitative survey aimed at general fault finding; however a quantitative survey would not have been appropriate in this instance and a for the purposes of this investigation, such methodology was considered satisfactory.
Flat Roof Leak Survey Findings
- Water gets in through the roof here.
- Large split in the flat roof. This is a perfect water entry point.
- Before the flood test; no water or moisture can be seen except for dry salts where previous water had traveled through the stone.
- Following flooding the flat roof with a bottom up methodology (ruling out the highest points first), we found water damage appearing at an early level and thus established the area responsible for ingress.
Conclusion Thermal Imaging Survey
There were some serious blisters and tares within the Triflex roofing system. These splits and blisters were, in this instance, almost always in line with, or within a correlatable distance of where the water has been seen to be affecting the inside. It was more than coincidental that the areas on the flat roof with splits and blisters (openings for water to ingress) were in line with the salt stalactites visible on the ceiling of the temple.
The thermal imaging survey, in collaboration with the flood test in these specific areas, supported this theory and the above report images demonstrate this. To prevent further leaks and water ingress, reparations to the roof should be made.
The largest problem that I observed was that the triflex flat roofing membrane did not appear to have been lain upon wooden decking, but directly onto the soft insulation boards. This is incredibly bad practice as it weakens and reduces the resilience of the roofing membrane if walked upon, and over time, as the sun heats it, you may find that the system subsides into the areas where the insulation boards meet. One such area had already split and this is where I made my bitumen repair during the inspection.
The roof should realistically be stripped back to the insulation, covered in ply or OS board, and re-protected properly with a product such as Kemperol V210 or a better quality Triflex system. Alternatively, do not walk on the roof, and repair the area around the dome, removing blisters and salt deposits, re-protecting with Kemperol V210. This product comes with a 25 year insurance backed guarantee. I would recommend contacting London Flat Roofing Ltd (www.londonflatroofing.co.uk) for these flat roof works.