Mold On Roof Trusses

Fact mold on the surface of lumber does not cause rotting or otherwise affect the strength of wood framing.

Mold on roof trusses.

Mold on attic sheathing. Cleaning mold from wood trusses and cross bracing. If that s mold and it looks like mold unless it s provided with enough moisture to start reproducing approx. The roof has baffles at alternating thusses soffit and ridge vents.

This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green. If you ve had experience with mold and mildew in the home you know the best mildew remover is chlorine bleach. I ve seen 2x4 s come off a lumber truck from the yard looking like that.

But outdoor heavy duty cleaning usually calls for more heavy duty mixtures such as tsp and chlorine bleach see the tsp page for more details or specialty additives such as jomax from rustoleum which combines a cleaner with a bleach activator. The mold itself may have a cottony texture but can also be velvety leathery or. Kshepard kenton shepard cmi june 18 2009 1 47am 5. This growth will cease once the moisture content drops to 19 or less.

Fungus and mold will grow on the trusses if the lumber moisture content exceeds and remains above 20. At the south end of the roof the ridge changes direction causing an overlay condition. If the wood used in trusses is kiln dried the moisture content is equal to or less than 19. Re roofing with lining lining papers sarking roofing felt can cause severe mold growth and rot due to reduced ventilation.

In an area of high levels of mold growth or moldy dust and debris the irregular surfaces formed by wood trusses and also by older wood cross bracing between floor joists prevents thorough cleaning of surfaces and creates many dust collection points. Skips a few trusses and reappears on the next panel or two. If the mold growth is thick may need to soak the trusses and plywood. Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.

The black mold is on the first 3 truss panels. In the vast majority of cases the mold growth is caused by condensation. 20 in the host material it will not release spores. A 10 x 10 area of plywood has been removed to provide air into this area.

Mold is a symptom of high moisture which if allowed to exist for prolonged periods can be damaging to any structure and will promote the development of wood decay fungi.