The answer to this question depends on several factors, including the condition of the existing shingles and the specific circumstances of the roof. In some cases, it may be possible to install valley flashing without removing the shingles, while in others, it may be necessary to remove and replace the shingles.
1. Metal Valley Flashing with Existing Shingles
When it comes to metal valley flashing, it is generally possible to install it over existing shingles without removing them. This type of flashing is typically installed in a “weave” pattern, where the metal strip is woven between the shingles on both sides of the valley.
However, it is essential to evaluate the condition of the existing shingles before deciding whether to install valley flashing without removing them. If the shingles are in poor condition, deteriorated, or buckling, it is advisable to replace them. Installing valley flashing over compromised shingles can compromise the effectiveness of the flashing and potentially lead to further damage.
2. Other Types of Valley Flashing
For other types of valley flashing, such as roll roofing or self-adhesive membranes, it is typically not recommended to install them without removing the shingles. These types of flashing often require a clean and smooth surface for proper adherence and may not be compatible with existing shingles.
In these cases, removing the shingles in the valley area is necessary to create a suitable surface for the installation of the flashing. This process involves carefully lifting and removing the shingles, installing the flashing, and then re-installing the shingles around the flashing.
Valley flashing plays a vital role in protecting a roof from water damage in valley areas. While it may be possible to install some types of valley flashing without removing shingles, it depends on the condition of the shingles and the specific circumstances of the roof. Consultation with a professional roofing contractor is essential to assess the condition of the shingles and determine the most appropriate method of valley flashing installation to ensure long-lasting protection and optimal performance of the roof.