Although I have been performing IR inspections of flat roofs for nearly 24 years, I am unaware of any printed resource that will enable you to accurately predict wind speed at roof level. Simply put, there are too many variables such as proximity to other buildings, building shape, architectural details, presence and height of parapet walls, etc.
My best advice is to pick a day when weather and site conditions are optimal. For a post-sunset inspection perfomed from the outside of the building, these include:
- Completely dry roof at sunirise
- Daytime high temps above 40F
- Mostly sunny day
- Roof level winds <15mp during daytime and during inspection
- Temps above freezing during IR inspection
All infrared data should be verified by destructive testing such as core samples or invasive moisture meter readings. Ideally, this should be done at the time of the infrared inspection. Unless you are capable of making permanent repairs, you may wish to engage a competent roofing professional to do this with you.
Should you confirm the presence of subsurface moisture, it is customary to outline the affected areas with spray paint. Thermal imagery along with other pertinent data should be contained in a written report along with a scaled drawing of the subject roof(s) showing the extent of wet insulation and the location of all invasive test sites.
Again, I would invite your attention to the Infraspection Standard for Infrared Inspection of Insulated Roofs. This document outlines the above procedures and requirements in detail and is available for $25 from the Infraspection Online Store.
As a point of information, infrared inspections of roofs is covered in detail in the Infraspection Insitute applications course, Infrared Inspections of Buildings and Roofs. This 16 hour course is available as an open enrollment class or through our Distance Learning Program. This course covers the above information and procedures and is designed to give you all of the information you need to accomplish these inspections successfully.
For more information you are welcome to call me or visit us online at:
Hope this helps.