US Patent 12116749 Method of rehabilitating a manhole

The method of repairing a manhole begins with assembling concrete forms above ground to correspond to the shape of the manhole wall. Then, a plastic liner sheet is wrapped around the assembled forms and the seams are welded. The forming sections are then removed, and the liner is placed in the manhole. An annular space exists between the liner and the manhole wall. The forming sections are re-assembled inside the liner. Concrete is then poured into the annular space and allowed to cure. The forming sections are removed, leaving the liner anchored in a new monolithic concrete wall fully engaging the old manhole wall.