Why Is Mold So Damaging To Today's Construction Materials?

  • By Air Care Wizard
  • Posted January 20, 2013
construction Materials damaged by mold

Leaky windows were not always such a big deal. More than a hundred years ago, exterior walls had hollow cores, or were made   of solid masonry or lumber. If they got wet from a window leak, they could dry. Many were built with heavy timber framing with plank wall , or even balloon-frame wall with true two-by-fours sheathed with 1-by-6 in. diagonal boards that were sheathed on the interior with plaster on metal or wood lath.Whether these walls are uninsulated or insulated, they are very mold resistant because both the materials and constructions can dry. The composite materials that are used today have adhesives that can be digested by fungi we call molds. Mold will also digest sugars and starches in wood fiber, if the cell walls have been crushed or broken. Solid lumber has intact cell walls that cannot be penetrated by molds. Molds will grow on the surface, but the wood will retain its structural strength. Particle board, oriented-strand board (OSB a.k.a. waferboard), and medium-density fiberboard, as well as paper-covered gypsum board, are full of adhesives, which make them good "mold chow.” Adhesives are used throughout
these materials to give them form and to hold together the crushed, pulverized, or torn wood fragments or particles that make up the board. Mold digests the adhesives, and mold hyphae penetrate the resulting cracks and holes between wood particles. Structural integrity is eaten away, and so is the wall. Paper covered gypsum board also has the adhesives and cellulose that offer food to molds at the expense of the wall.

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