Silicone sealant. Here's how to use it.
Silicone sealant is used to seal joints between two surfaces. It can be used indoors or outdoors, between almost any surfaces. It’s pretty useful stuff. Here's how to use it.
See the full guide here: https://www.mitre10.co.nz/guides-and-advice/guide/how-to-use-silicone-sealants