Seattle Environmental Mold Testing Inspection Reports
Below are recent inspections of environmental mold issues we’ve performed in Seattle.
Project Type > Environmental Mold Testing for a Home in Seattle
REASON FOR INSPECTION:
- Client has been experiencing water damage to the ceiling of his home. He has suspected roof leaks but numerous roofers have not been able to discover any leaks. Client requested an inspection to determine the cause of the water intrusion.
- This single family 2 story residential property was built in 2013 and is 2,260 ft².
CAUSE OF MOLD:
- Mold growth and water damage is the result of blocked ventilation inside the ceiling cavity(s) of the roof.
ANALYSIS OF YOUR RESULTS:
- Extreme Amplification: Mold spores were detected at levels many times greater than the threshold, indicating a site of mold amplification and growth. Please refer to the attached report for more detailed information.
The most likely contributor of the elevated mold spores is:
- Opening of the ceiling cavity and the disturbance of the insulation inside the ceiling cavity is the most likely cause of the current amplification.
- Due to the elevated levels of mold spores, the operation of a commercial HEPA air scrubber is recommended. This will rapidly lower the indoor mold spore levels. Please contact Environix for pricing.
- Once the mold growth in the ceiling cavity has been treated and the area re-insulated and sealed, the air quality should quickly return back to normal.
RELATIVE HUMIDITY & TEMPERATURE READINGS:
LOCATION: Upstairs Hall
- Several areas of water staining noted on the ceiling as well as below an electric outlet found on the North facing wall.. No elevated moisture was currently noted in the sheetrock of any of these areas.
- This home has a low pitch roof. Mold and condensation problems are commonly found in low angle roofs. The minimal pitch found in a low angle roof reduces the opportunity for the stack effect to move air along the underside of the roof sheathing. This leads to stagnant air and condensation.
- This home has vaulted ceilings: Vaulted ceilings limit the available space for in-ceiling insulation and, as a result will often result in blocked venting of the ceiling cavities.
- The ceiling in the upstairs hall had been previously opened for inspection in an area approximately 12” x 12”.
- Light to moderate mold growth and mold staining was noted on the OSB sheathing within the inspection cavity.
- Elevated moisture measured at 90% in the building materials within the inspection cavity.
- Insulation is blocking the ridge vent holes at the top of the roof line. This is evidence from the insulation stuck to the underside of the OSB sheathing.
- Low Pitch Roof – Providing sufficient venting for low pitch roofs is extremely difficult. The challenge occurs because a flat roof has very little natural air movement. Even with vents in the peak of the roof and the perimeter, the air tends to stagnate. This in turn leads to condensation and mold growth.
- Due to the fact that water damage and staining have only been noted in one area, it is possible that insulation was blocking only one of the existing ridge vents. Unfortunately, this cannot be confirmed unless sections of the ceiling or sections of the roof are removed to inspect each ceiling cavity. Client may wish to take a progressive approach to resolving this problem.
- The simplest and least expensive solution is to clean and treat the existing mold growth noted on the OSB sheathing that is visible / accessible from the 12”x12” access hole that is already present. Once the mold has been treated, insulation can be re-installed (taking care to maintain a 2” air gap between the insulation and OSB sheathing and taking care NOT to block the venting at the top of the roof.). Once this is done, the hole can be patched and then painted. If this solution is chosen, it will be imperative to pay close attention to relative humidity levels inside the home during the winter and keep them below 50% to minimize the chances of condensation from occurring inside the ceiling cavity. Client will need to watch for signs of water staining, paint bubbling or drywall tape peeling. If these symptoms begin to show up again, additional changes to the roof system will be necessary.
- The most recommended solution to low pitch roofs requires installing a layer of rigid foam insulation directly onto the top of the roof sheathing. This prevents condensation and eliminates the need for ventilation since the dew-point inside the ceiling cavity is changed.
- Please contact Environix for additional information and options regarding low pitch roof system venting.