Replies

1. 
   pkrivanec711 | Jan 23, 2024 12:00pm | #1

   The OSB should dry out, once the water source has been corrected. I would suggest you review the OSB after it has had a chance to dry out, before reroofing that area. Depending on how long this wetting has occurred, it may have compromised the integrity of the sheathing.

   SS metal roofs are allowed to be installed over asphalt shingles. Depending on how old the roof is and the make-up of the shingle roof system (underlayment), it might be worth removal of the original roof. Here is a video that discusses this as a Q&A.

   https://www.youtube.com/watch?v=oarZwnTTvFI

2. 
   avenger | Jan 26, 2024 07:47am | #2

   hi!
   First of all, it is necessary to assess the extent of damage to the OSB. If the OSB board is wet but has not lost its structural integrity or begun to swell or rot, it may be okay to leave it after the leak is repaired. However, if the OSB is swollen, warped, or shows signs of rotting, it will need to be replaced.
   Once the leak is fixed, it is important to ensure good ventilation to ensure the OSB is completely dry. This can help prevent further deterioration of the material and mold growth.
   Laying a standing seam metal roof over a single layer of asphalt shingles is a common practice. However, it is important to ensure that the foundation for your new roof is in good condition. If your asphalt shingles are old or damaged, it is best to remove them.

3. 
   alii786 | Jan 27, 2024 03:18pm | #3

   If you've discovered that the OSB (oriented strand board) sheathing in your garage roof is wet, it's essential to address the issue promptly to prevent further damage and potential mold growth. Here are some steps you can take:

   1. **Identify the Source of the Water**: Before proceeding with any repairs, try to identify the source of the water that caused the OSB sheathing to become wet. It could be due to a leak in the roof, damaged flashing, or inadequate ventilation. Fixing the underlying issue will prevent the problem from recurring.

   2. **Assess the Condition of the OSB**: Evaluate the extent of the water damage to the OSB sheathing. If the damage is minimal and the OSB is still structurally sound, it may be possible to dry it out without needing to replace it. However, if the OSB is severely water damaged, swollen, or showing signs of delamination, it's best to replace it to ensure the structural integrity of the roof.

   3. **Dry Out the Area**: If the OSB sheathing is wet but still salvageable, you can try to dry it out by improving ventilation and allowing air circulation in the affected area. You can use fans or dehumidifiers to speed up the drying process. Make sure to monitor the moisture levels regularly until the OSB is completely dry.

   4. **Replace Damaged Sections**: If the OSB sheathing is extensively damaged or if it doesn't dry out properly, it's advisable to replace the affected sections. Cut out the damaged portions of the OSB and install new sheathing in their place. Be sure to properly seal and flash any joints or edges to prevent future leaks.

   5. **Re-Shingle the Area**: Once the OSB sheathing is dry and any damaged sections have been replaced, you can proceed with re-shingling the area. Make sure to use high-quality roofing materials and follow proper installation techniques to ensure a watertight seal.

   6. **Inspect Regularly**: After completing the repairs, periodically inspect your roof for any signs of water damage or leaks. Address any issues promptly to prevent further damage to your roof and property.

   In summary, whether you need to replace the OSB sheathing will depend on the extent of the water damage and the condition of the material. In many cases, if the damage is minimal and the OSB can be properly dried out, it may not need to be replaced. However, if the damage is severe or if the OSB does not dry out adequately, it's best to replace it to ensure the long-term integrity of your roof.