Thermal shock/roof dehydration costs you money

Thermal Shock-sounds ominous but what is it and what does it have to do with your commercial roof and more importantly, how is it costing you money?

Thermal shock is a term describing the temperature swing in a day. An example of this is inLos Angeles,CA. During the day we will get the temperature rising up to 90-100 degrees just to use an average in the summer. The roofing material will absorb heat and reach temperatures of 150 to 170 degrees and then as evening comes about the temperatures drop down to 50-60 degrees by morning. This swing of 90-100 degrees of the roofing material is thermal shock. I've worked in desert areas where we have had 90 degrees during the day with the roofing and roof metals heating up to 150 degrees and then dropping down to 35 degrees or just above freezing by morning - a 115 degree swing. This creates movement.

Heat expands - cold contracts. Your roof is doing this on a daily basis for years. I have personally seen a tear in a roof that was closed in the morning and hard to see but by late afternoon as temperatures rose, the tear became a ½ inch opening.

When your roof was first installed and new it had a lot of flexibility and resistance to this expansion and contraction with the tars fresh with all their oils.

Keep in mind that roofs are exposed to the elements like wind, heat, rain, cold, and UV 24 hours a day, 7 days a week and over time these tars get dried out and lose their flexibility. This at first is slow to show up in any major or dramatic way but what you will start to notice on the roof is the top layer or cap sheet having a surface embedded with mineral granules to help protect it from the sun. The granules are the protective barrier between the asphalt based compounds and the sun's damaging effects.

As the roof dries out these protective mineral granules begin to lose their adhesion and start separating from the surface. When this occurs it accelerates the general failure of the capsheet. As this continues you will see more and more granules coming off and then strands of fibre glass reinforcing becoming exposed.

As the sun continues to beat down on the roof, it dehydrates or dries out and loses flexibility becoming brittle and no longer water proof.

When you combine the movement in the roof from temperature swings and a dry or brittle condition you start to get areas of the roof separating or pulling apart. Now your repairs will start.

Please keep in mind that this is all on a gradient taking a number of years. As the roof continues to dry out the repairs become more frequent with new areas opening up or the old repairs opening up again. Repair bills eventually mount up until you reroof again. The cycle I have described above happens over a period of 7 to 15 years, the average service life of a hot mop roof depending on geographical location and conditions. The competence of the roofing contractor, quality of materials used and maintenance over the years can also affect the service life of the roof.

The effects of the sun on your roof shortens the life of your roof and this costs you as a building owner because the shorter the roof life the more repairs or reroofing you will have. The longer a roof lasts the less it costs.

Commercial Cool Roof Systems has a solution for roofs of almost any age.