Attics on the pacific west coast can be prone to organic growth (mold/mildew) on the roof sheathing. The main cause is high relative humidity and usually inadequate ventilation. You should also check the attic for evidence of roof leaks.
Watching out for these deficiencies enables minor repairs to be completed before they escalate, and become more expensive to remediate.
Now is a good time to check on the condition of your attic.
Here’s what you should be looking for:
- Evidence of the roof leaking usually manifests as patches (localized staining), or in proximity of any roof penetration including roof vents, skylights, exhaust vents and masonry chimneys.
- Check the attic for detached bathroom and laundry ducts, including the entire run from the ceiling to the roof sheathing. Detached laundry or dryer exhausts can add a significant amount of moisture and heat required for mold spores to germinate.
- Check the attic hatch for the presence of insulation and weather stripping. Although the hatch area can be small, an uninsulated and non-weather-stripped hatch provides access to the attic for warm and moist household air.
- Check the insulation at the edges of the sheathing and soffit (roof overhang). Air flow from the perforated (vented soffit) can sometimes be blocked by insulation. For an attic to ventilate efficiently, air flow enters from the soffit and flows out via the top vents (ridge/roof gable/turbine vent). If you find the soffit ventilation blocked, the easy solution is to fit pre-made plastic ducts/baffles – a simple push fit that restores air flow.