How to Properly Seal a Roof Eave Connection
Understanding Challenges, Myths, and Correct Application
A properly sealed roof eave connection is crucial for the durability and functionality of your roof. This article highlights common mistakes and misconceptions and provides a simple guide on how to seal the eave connection correctly – using the ideal product: Rissan 420 Black.
What is the eave connection on a roof?
The eave connection is the transition between the roof surface and the gutter. This area is particularly vulnerable to weather conditions and moisture, making a reliable seal essential. A poor connection can lead to water ingress, which may damage the roof structure.
What kind of eave connection does my roof need?
The choice of the right eave connection depends on how the sub-roof drains water. If the roofing underlay drains into the gutter, Gebäudehülle Schweiz recommends four connection options – including the SIGA solution.
⚠️ What are common mistakes?
One of the most frequent mistakes is failing to extend the roofing underlay into the gutter. Additionally, many installers use Twinet 20 instead of Twinet 40, even though Twinet 40 is essential for the eave connection due to its larger adhesive surface.
Important:
• Twinet must be adhered flush to the upper edge of the metal flashing.
• The roofing underlay must be cut flush with the lower edge of Twinet 40.
What to consider regarding SIA Standard 232/1?
In Switzerland, SIA 232-1 regulates the requirements for sub-roofs in pitched roofs. There are three levels of exposure classification:
Normal exposure, Increased exposure, Extraordinary exposure
For extraordinarily exposed sub-roofs, water must be drained into the gutter. The eave connection must be UV-resistant for 2.5 times the counter-batten height.
These exposure classifications affect only the choice of sub-roof material and the installation method in ridge areas. In general, paying attention to detail and understanding the consequences of different exposure levels is crucial.
Why is Rissan 420 Black perfect for the eave Connection?
Rissan 420 Black offers:
✅ Robust construction – Reliable even under heavy foot traffic.
✅ Stable liner and carrier – Tear-resistant, precise, and easy to apply.
✅ Black colour– Discreet and aesthetically pleasing, especially for deep-set eaves.
✅ Non-slip surface – Ensures safe footing when working on the eave.
✅ UV stability – Essential for direct drainage into the gutter, as the eave membrane is permanently exposed to UV radiation.
How to properly install an eave connection?
1️⃣ Ensure the metal eave flashing is free of grease, dry, and dust-free.
2️⃣ Adhere Twinet 40 flush to the upper edge of the metal flashing.
3️⃣ Adhere the roofing underlay onto Twinet 40.
4️⃣ Cut the roofing underlay flush with the lower edge of Twinet 40.
5️⃣ Apply Rissan 420 Black (60 mm) onto the flashing and carefully seal all transitions.
Watch this process in action:
Similar articles
