How to reroute an old drainage pipe in my house?

 
Plan and Assess the Project
 

Experienced teams in St. Louis and Nashville have found that careful planning is key to a successful drainage project.

 

• Evaluate the existing layout and identify the section of the old drainage pipe that needs rerouting. Determine if the pipe is connected to your stormwater or wastewater system.
• Sketch a detailed diagram of the current piping arrangement and the proposed route, considering gravity flow and the need for proper slope.
• Examine local building codes and regulations to ensure the new routing complies with structural, environmental, and health standards.
• Plan for any additional modifications that might be needed such as new fittings, clean-outs, or access points.

 
Gather the Necessary Tools and Materials
 

• Prepare tools such as a shovel, pipe cutter, hacksaw, drill, and gloves. Depending on the pipe material (PVC, cast iron, etc.), you might need specialized cutting tools.
• Obtain replacement pipes, couplings, brackets, primer and cement (for PVC), or mortar and sealant (for cast iron), and other fittings required for secure connections.
• If the new route requires penetrating walls or floors, collect appropriate drill bits, sealants, and waterproofing materials.
• Have safety equipment readily available such as goggles, masks, and sturdy boots.

 
Prepare the Work Area
 

• Clear the work area of any obstacles and protect nearby surfaces with drop cloths or plastic sheeting.
• If working indoors, ensure proper ventilation. If in a confined space, consider using a portable fan or working in stages to maintain air quality.
• Shut off the water supply if the pipe is connected to the home’s system, and remove any standing water from the floor to avoid slips or additional damage.
• Notify household members or neighbors about the planned work, especially if any disruptions might occur.

 
Disconnect and Remove the Old Pipe Section
 

• Carefully disconnect the old drainage pipe while noting the alignment of joints and fittings. Use appropriate tools to avoid damaging adjacent connections.
• Retain any pieces that can be repurposed; discard any sections that are corroded or damaged beyond repair.
• If the pipe runs through walls or under floors, mark exit and entry points for reference during reinstallation.

 
Excavate and Prepare the New Pipe Route
 

• If the new pipe will run underground or through a trench, dig along the proposed route ensuring a uniform slope for proper drainage (typically a 1/4 inch drop per foot is standard for most drainage systems).
• Remove any debris or unstable soil from the trench to prevent future settling or pipe misalignment.
• For indoor rerouting, clean and prepare any accessible wall or ceiling cavities. Cutting access holes may be necessary.
• Double-check that the new route will connect seamlessly with the remaining sections; verify the depth and slope before moving on.

 
Install the New Drainage Pipe
 

• Dry-fit all sections of the new pipe along the planned route to ensure they meet correctly. Ensure that the pipe’s slope is consistent from start to finish.
• Begin connecting pipes using the appropriate method for your pipe material. For PVC, apply primer and cement to all joining ends; for metal pipes, use a proper sealant or gasket.
• If the rerouted pipe requires bends or offsets, use designed fittings that maintain the needed slope and prevent clogging or backflow.
• Secure the pipe to surrounding structures with brackets or straps at regular intervals to prevent movement and undue stress on the joints.

 
Reconnect and Test the System
 

• Re-establish any connections to the main drainage system or septic tank. Make sure all joints and fittings are tightly sealed.
• Slowly restore the water supply or flush the drainage system to check for leaks, misalignments, or blockages.
• Monitor the flow at each connection point, watching for pooling water or signs of drainage backup. Allow the pipe to run water through several cycles to ensure proper operation.
• If any issues are detected, repair or adjust connections and retest until the system operates flawlessly.

 
Finalize and Clean Up the Work Site
 

• Once the system is confirmed to be working correctly, secure any exposed pipe sections both aesthetically and structurally.
• Patch any walls or floors that were cut for access and apply waterproof sealants if required.
• Backfill any excavated trenches with proper soil and compact it to avoid future settling. If the pipe runs within a wall or ceiling, repair and repaint as needed.
• Dispose of all waste materials according to local guidelines and store tools safely.

 
Consider Professional Assistance if Needed
 

• If complications arise, especially with structural modifications or unexpected obstructions within walls or floors, hire a licensed plumber or contractor to ensure safety and compliance.
• Consult a professional for guidance if you’re unfamiliar with local plumbing codes, particularly regarding drainage slope and venting requirements.