Church Floor Lifting

Church Floor Lifting, Virginia Beach, Virginia

Structural Engineer:  William J. Klunk, Jr, PE, Lynnhaven Engineering, PC, Virginia Beach, VA www.lynnhavenengineering.com

Problem:

Floors adjacent to exterior walls settled inside of education rooms at church. Floor also settled at transition between original footprint of church and addition in hallway, causing a trip hazard and surface deterioration.  The floor had settled approximately 1.5 inches against the exterior walls of the building. This also resulted in stair-step cracking of the interior masonry walls which were built on the slab floor.

The independent structural engineer identified poor exterior drainage and natural consolidation of poorly-placed backfill material during construction as the cause of the problem. There were no signs of settlement or movement of the exterior walls adjacent to the work area.

Solution:

High density polyurethane grouting for void filling under and lifting the interior floor. Polyurethane concrete raising was used to lift and stabilize floor over an entire area of 100 linear feet of exterior and interior walls. The customer addressed the exterior drainage problems prior to the polyurethane concrete raising floor lifting work.

Geotechnical polyurethane was chosen as the lifting material due to is clean, fast installation, compared to cementitious or sand-based grout, replacement of slab pier installation. Polyurethane injection is the most effective material for lifting slab-on-grade foundation elements, as it lifts large areas gently without point loading.

Results:

The floor lifting work took a total of approximately three hours, start to finish, using a single polyurethane grouting crew. The crew drilled through the existing VCT flooring tiles to inject the high density polyurethane through 5/8″ holes. After the work was completed, flooring restoration was completed by the customer.