Which statement regarding modified bitumen roofs is true?

Modified bitumen roofs are known for their performance characteristics and specific installation techniques. The statement that there is evidence of bleed out of asphalt at the seams is true because modified bitumen membranes are composed of layers of asphalt that can sometimes seep or ooze, particularly in warm weather conditions or when the material is heated during installation. This phenomenon, known as "bleed out," can happen at the seams where two pieces of the membrane are bonded together. Proper installation practices typically aim to manage this bleed out effectively to ensure the roof performs optimally and maintains its integrity.

The other statements are not accurate representations of modified bitumen roofing systems. The seams are spaced based on the manufacturer's recommendations and specific install guidelines, and they usually do not have a set distance of every 2 feet. While maintenance requirements may vary, modified bitumen roofs are not considered completely maintenance-free; regular inspections and upkeep are recommended to prolong their lifespan. Lastly, a base sheet may often be installed as part of modified bitumen roofing systems, depending on the specific system and installation requirements.