While you can apply roofing tar at lower temperatures it will not properly set until it reaches 70 degrees.
Roof tar temperature.
The ideal temperature is 70 degrees f.
When applying roofing tar make sure that you have at least a few consecutive days of sunshine without rain or snow so that the tar has time to cure.
If the asphalt is applied below the ideal.
We include the properties of asphalt such as its melting point and flash point and we describe the properties of asphalt used in the manufacture of roof shingles.
At low temperatures of 7 degrees c to 4 degrees c 20 39 degrees f asphalt temperature may drop 20 degrees c 50 degrees f in a matter of seconds.
Temperatures of asphalt shingles.
However this is more challenging in the winter.
The rooftop temperature results from two different properties.
Ideal temperature to get the best results and to prevent breakage or softening of materials install roofing when the temperature is between 50 and 60 degrees f if at all possible.
At hotter temperatures.
The ability of the material to reflect the sun s energy back into the atmosphere called solar reflectance and the amount of heat the material rejects instead of absorbs called thermal emittance both are measured on a scale from 0 to 1 with higher scores translating into cooler roofs.
Cold air can rob the asphalt of its heat between the roofing kettle and the roof s surface.
When to tar a roof.
Avoid roofing in temperatures above 80 degrees f to eliminate these issues.
This article describes the different temperatures involved in asphalt roofing product manufacture and compares that to the on roof temperatures to which asphalt shingles are exposed when in service.