Best Tunnel waterproofing Service In India https://structural-india.com/tunnel-waterproofing/ Similar to laying a floor in tunnelling, you’ll need to cover the tunnel with waterproofing membrane to make it watertight. This time, though, the membrane will run along the full depth of the tunnel. After the foundation is in place and the tunnel is pressure-tested, workers will start the process of “spraying” the waterproofing membrane. It’s important to note that this is not a crawlable tunnel.