# Waterproofing Undrained Screed ### Issue Image: ![[Pasted image 20241121123016.png]] ## Issue Description: - It is often good practice to provide a double layer membrane system. - Detailing around puddle flanges is especially important when using this system. - The benefit of using a double membrane will be compromised if it not detailed correctly. - The puddle flange junction shall be detailed so that tHe screed underneath the top layer of membrane shall be capable of draining. - This issue is neatly explained in this video created by GripSet [How Puddle Flanges Work to Drain Below Screed](https://www.youtube.com/watch?v=1lM_9S7OYcI&t=343s&ab_channel=GripsetIndustriesPTYLtd) ## Actions to Prevent this Issue: - [ ] Architect shall check that the puddle flange junction shall be detailed so that the screed underneath the top layer of membrane shall be capable of draining. ## Source