How to Replace Prefabricated Beams in Houses

Replacing prefabricated beams in houses requires selecting appropriate methods based on the type of house and specific circumstances. Here are the key operational points for common scenarios:

Prefabricated lintels in rural self-built houses If cracks are found in the prefabricated lintels during the construction phase of the house, immediate replacement is necessary. The operation involves removing the existing lintel, cleaning the contact surface, and installing a new beam, ensuring tight contact and accurate positioning with the wall. If cracks are discovered in the lintels after the house is completed, the cause of the cracks must first be investigated: check for foundation settlement, wall cracking, or damage to the lintel due to long-term loads or temperature changes. If replacement is confirmed necessary, the wall above the lintel (if brick-built) must first be removed, the old beam gradually extracted, and the new beam installed before restoring the wall. Note that temporary support for surrounding structures must be provided during construction to avoid collapse risks.

Beam replacement in rural red-brick houses For beams in red-brick houses that serve a similar function to prefabricated beams, if a fractured beam needs replacement, there are two methods:

1. Full roof tile removal method: All roof tiles must first be removed to expose the beam's position. After removing the fractured beam, a new beam is installed, and the tiles are then relaid. This method is suitable for cases where the beam is severely damaged or requires comprehensive inspection and repair, but the construction period is longer.
2. Partial hole-cutting method: Cut open a few bricks in the roof at the position corresponding to the fractured beam to create an operational space and directly insert a new beam. This method causes less damage to the roof but requires ensuring that the new beam is firmly connected to the surrounding structure to avoid local stress concentration.

Beam replacement during house renovations The 'sandwich mountain' method is used for interior walls:

1. Support and reinforcement: Set up temporary supports (such as steel pipes or wooden columns) on both sides of the interior wall to be removed to ensure the safety of other structures during removal.
2. Remove the interior wall: Gradually remove the interior wall to the height of the beam's bottom, exposing the position of the original beam.
3. Install the new beam: Install a new beam above the removed position, drive columns (such as reinforced concrete columns) into the walls on both sides to enhance stability, and secure the new beam with bolts or welding.
4. Curing and acceptance: Cure for approximately 15 days in summer and extend the curing period appropriately in winter. After confirming that the new beam has no settlement or deformation, remove the supports and repaint the wall.

Beam replacement in 30-year-old prefabricated panel houses Strict adherence to reinforcement and renovation specifications is required:

1. Temporary support: Set up steel pipe supports every 1.2 meters along the length of the prefabricated panel, and use H-section steel beams for underpinning at critical nodes, with a beam section of no less than 200*200 millimeters.
2. Structural inspection and repair: Remove the original filling material from the panel joints, implant No. 6 deformed steel bars, and pour C30 fine aggregate concrete; add constructional columns (with a section of 240*240 millimeters) at the four corners of the house, tie the steel bars, and connect them to the floor slab.
3. Segmental removal: Follow the principle of 'middle first, then sides', with a daily removal amount of no more than 30% of the total floor area. Continuously monitor the stress changes in the support system and prohibit removal by heavy hammer impact.