Adding an access point to a mesh system?

[One More Solo]

I've got a Deco mesh system set up in the house but we need to extend our wireless coverage to the garden - can I add an access point (like the TP Link EAP110) to do this? My understanding is the AP would have a different SSID?

 

[ChrisD.]

Doesn't it make more sense to add to your Deco system so that it also covers the garden?