Do Water Pipes or Stone or Brick Surfaces “Sweat” in Buildings?
No. Why does water condense on your cold water pipes overhead in the basement before it condenses on the steel Lally columns supporting your main girder? Perhaps because cold water (at 40 deg.F.) is running through the water pipe, cooling its surface to a lower temperature (40 deg.F.) than that of the Lally column (perhaps 55 deg.F.). Water pipes do not “sweat” as people say – water is not exuding out of pores in the pipe. Water is condensing from moist air onto the surface of the cold water pipe. Insulate your cold water pipes to avoid condensation and drips onto the floor. It looks like sweat, but it’s not. For a different reason, that of energy efficiency, you might want to insulate your hot water and heating pipes in a basement as well, though in some conditions we are so desperate to warm and dry a problem area that we deliberately leave the hot water and heating pipe insulation off so that we can steal some of their heat to warm and dry an area. Similarly, moisture will condense
