The washing machine upstairs drains water, and the corner of the floor downstairs bubbles.

In this case, there should be a problem with the sewer pipe or waterproof.

Find a property management company first, and carry out rectification and renovation according to the building code. If the water pipe is broken, please replace it. It's not the water pipes. In the rectification, first find the water seepage part, apply waterproof sealant at the joint of the brick, and check whether the tile is empty. If the empty drum part must be a water seepage part, strengthen the treatment of this part, apply waterproof sealant at the joint between the wall and the ground, and seal the gap between all wall-penetrating pipes and the wall. Pay attention to the smooth drainage of floor drain. If water seepage still exists, it is recommended to redo waterproofing.