First figure how short you are let s say you re 3 8 shy of making a connection.
Tub spout copper pipe too short.
However try not to wiggle the spout and pipe because too much jarring may cause problems with the plumbing in the wall.
The 1 2 copper pipe coming out of the wall is only an inch long and we need a minimum of two for the faucet to fit.
Cut a piece out of the copper pipe 1 long.
If the copper stub out penetrating through the wall is too short once the old spout is removed extend the copper tube length using the copper extension nipple.
As i see it i now have two options to fix the problem.
That means with the tile you can no longer reach the threads in the spout.
If you find that your copper pipe is too short for attaching your tub spout then with the right tools you can fix this problem yourself.
Or if your copper stub out is already long you could buy a tub spout that slides onto bare copper pipe.
Total the two and add 1 4 inch.
The result is the overall length of the pipe you need.
How to install a slip on tub spout.
For slip on tub spouts your copper pipe should be a minimum 1 and a maximum 2 7 8 in length.
1 to remove tile and cut through the backer board remove and replace the copper nub by soldering a longer copper tube to replace the shorter one.
Then measure the distance from the surface of the wall to the back of the threaded elbow inside the wall.
Measure the length of your tub spout from the back edge of the spout to the front where the threads start on the inside of the spout.
Now cut another piece of 1 2 copper 1 3 8 long you may now solder the piece in using two couplings or two sharkbite connectors.
Copper pipes conduct heat well allowing hot water to stay warm.
This video to show you how to solder it but it does give me an idea of what to do where to place your male adapter and how to cut and measure the line for t.
They also offer wonderful durability flexibility resistance to bacteria and ease of installation.
The obvious thing would be go from the back and just replace the tube in the fitting but the back wall is plaster lath and in the middle of the living room.