Three Important reasons for Airtightness
Up to 90% of all heat loss is due to air leakage through the building fabric. Making the building air tight is the main factor in achieving top energy efficiency. Consider an airplane when flying at 35,000 feet the plane is exposed to an outside air temperature of –50F (-46c) with a wind chill factor as low as -150F (-101c). The body of an airplane is typically just 2 inches thick, but passengers don’t freeze because it is airtight. Once a structure is airtight it takes very little energy to maintain a consistent temperature.
Water can enter a building in 2 ways, either as a liquid or as a vapour. Controlling how water enters and leaves a building is an important step when trying to maintain a durable building, as over 90 percent of building problems are moisture related. Excessive water in a building envelope will compromise the structural integrity of the building.
Standing water and water damaged timbers or insulation can quickly result in the growth of mold and bacteria and this can lead to an insect infestation. Mold growth is a real concern because mold spores in the air can result in headaches, breathing difficulties, allergic reactions and can aggravate asthma.