How to Replace Hidden Copper Pipes Without Tearing Down Drywall

Replacing hidden copper pipes without tearing down drywall can seem daunting, but with the right preparations and tools, it can be done efficiently. Here is a comprehensive guide on how I go about replacing hidden copper pipes without major demolition.

Locating the Pipes

The first step is locating exactly where the pipes are running within the walls. Here are some methods I use:

• Consult building plans - If available, the original building plans can show pipe layouts and give a rough idea of where they are.

• Inspect exterior - Go outside and look for any piping extending from the exterior walls. This shows where lines enter the house.

• Follow along accessible areas - Pipes usually run vertically within stud bays, so I follow where they are visible to locate the hidden sections.

• Use pipe locator - A stud finder that detects metal can help find exactly where pipes are. I mark these spots so I know where to cut open the drywall.

• Listen for running water - Having someone turn taps on and off while I listen against the wall can indicate pipe locations by hearing water flowing.

Gathering Tools and Materials

To access and replace hidden copper pipes, I make sure to have the following tools and materials on hand:

• Utility knife - For scoring drywall so it cuts neatly

• Reciprocating saw - For cutting openings in drywall and cutting pipes

• Drywall saw - For precise cuts if a utility knife alone doesn't penetrate the drywall

• Pry bar - To pull drywall off the studs after cutting an access hole

• Plastic sheeting - To cover floors and furniture from dust and debris

• Shop vac - For cleaning up drywall dust and particles

• 1x4 lumber - To brace cuts in the drywall for clean access points

• Copper pipe - Same size as the original pipes

• Fittings - Tees, elbows, couplings, etc. to reconnect piping

• Emery cloth - For cleaning pipe ends before soldering

• Tube cutter - For evenly cutting new pieces of pipe

• Propane torch - To heat joints for soldering

• Solder and flux - For joining the new copper pieces

• Drywall patches - To patch over access holes later

Cutting Access Holes

Once I've located the pipes within the walls and have the right tools, it's time to cut access holes. I follow these steps:

• Mark the opening with a utility knife by scoring the drywall face paper. Make it a few inches wider than needed.

• Use a drywall saw to cut through the paper at corners to allow the drywall to break away cleanly.

• Carefully cut out the opening using a reciprocating saw. Go slowly to control the blade.

• Use a pry bar to pull the drywall piece off the studs. Pry against the studs, not the remaining drywall.

• Brace the openings with 1x4 lumber screwed into the studs to prevent damage to the surrounding drywall.

Replacing Pipes

With safe access holes cut, I can now work on the pipes themselves:

• Shut off main water supply and open faucets to drain lines. Catch water in buckets.

• Cut out the damaged pipe sections using a reciprocating saw or tubing cutter.

• Dry fit the new pipe pieces to ensure proper fit before soldering.

• Sand pipe ends and fittings with emery cloth to remove oxidation and ensure good contact.

• Apply flux to pipe ends, then solder new pipe and fittings in place. Work safely due to open flame.

• Allow joints to cool completely before re-pressurizing. Inspect for any leaks.

Patching Drywall

Once the pipes are replaced, I patch the drywall openings:

• Remove any bracing lumber once pipes are complete.

• Vacuum all drywall dust and particles. Ensure edges are clean.

• Apply drywall compound over seams and screw indentations. Let dry and sand smooth.

• Apply joint tape over large seams and compound over it. Feather out edges.

• Prime and paint when fully dry. Match surrounding paint for seamless results.

• The patched holes are now ready to be hidden once again within the walls!

Replacing hidden copper pipes without destroying drywall is very manageable by carefully locating, accessing, and repairing them. Using the proper tools and methods allows plumbing repairs without major demolition or expense. With some planning and patience, the drywall damage can be minimized.