I am in the process of pour a new concrete patio. I am thinking it would be nice to run some low voltage to the middle of the patio to provide lighting to a dining table. I was thinking of running pvc conduit under the patio to a brass junction box that would be set in the concrete and typically under the umbrella stand. Hoping to mount some small low voltage fixtures in the umbrella and/or under the table. Thinking only 5-10 watts of LED.

My main concern is if I decide to move things around. I want to be able to seal up the junction box and not have it get in the way. Anyone done something similar? I have a simple battery powered solution but having the opportunity to go under the patio got me thinking...