<p>Shower and faucet installation involves shutting off water, removing the old fixture, installing the new valve body (ensuring it's level and oriented correctly), connecting supply lines (often PEX), testing for leaks, then installing the trim, handle, tub spout (if applicable), and showerhead, using <a href="https://www.google.com/search?sca_esv=5bb9be823fc6d962&amp;q=Teflon+tape&amp;source=lnms&amp;fbs=AIIjpHz30rPMyW-0vSP0k1VTNmO_kCOARpjPjQRkBWH2HwUIz5XUSIJvSK0oms7XOxizDlmapc3S9dUP-_MTiIHH95Wkon-Ttfr0Wmh8wJZaNgFAiASZ186sqFQ8Ew9Fd33MWSKF45pzcswjjEqQbXYmivgE8U5DjjMU7ASYPeg2AIvWsAqhm3aAMum5SEJhEhPsoSQxkx3OOJXerTluPsCWl3iSdQ-m9AfPzmpCyeSOP3RVbqRCw9s&amp;sa=X&amp;ved=2ahUKEwjrwOjtlPKRAxWxUGcHHRlWFU4QgK4QegQIARAE&amp;biw=1366&amp;bih=607&amp;dpr=1&amp;mstk=AUtExfB6-Wnr2gMJVCq2G1VfLqU1Oy1UmPno3IKQGnI-3oaPI9sPQMM_pAMd7pTTYdoPZFxpRvIA25m0l8vnnfPmwt15Md2NGoEjhS9O9AVEFHwQdaRTKonv8_jSRYOJ1ipfUgaBai6-46FgzoTyxqWa-0T_OhdE4AkGB2F3xKNCDoD-hfg&amp;csui=3">Teflon tape</a> and sealant for watertight connections, with the final trim often siliconed to the wall for sealing.&nbsp;<br><br><strong>Key Steps for Installation</strong></p><ol><li><strong>Shut Off Water &amp; Prep:</strong> Turn off the main water supply, drain lines, and gather tools like a PEX crimper, Teflon tape, sealant, and a level.</li><li><strong>Install the Valve Body:</strong> Mount the valve so the "up" arrow points up and it's flush with the finished wall surface (or correct depth for tile).</li><li><strong>Connect Supply Lines:</strong> Use PEX or copper to connect hot/cold lines to the valve and run the shower riser pipe (for the head) and tub spout line, ensuring proper fittings like drop-ear elbows.</li><li><strong>Test for Leaks:</strong> Turn water back on briefly to check all connections for leaks before sealing the wall.</li><li><strong>Install Trim &amp; Head:</strong><ul><li>Insert the cartridge (hot on the left) and secure the bonnet nut and O-ring.</li><li>Install the trim plate and handle, securing with screws and set screws.</li><li>Apply Teflon tape/sealant to the shower arm, thread into the valve, and attach the showerhead.</li><li>Apply clear silicone around the trim plate where it meets the wall for a watertight seal.</li></ul></li></ol>