DEPRESSED JOINT FILLER

To effectively protect joint edges against spalling, a filler must be flush with the floor surface and held in place sufficiently firmly to support imposed wheel loads. If you find that the filler was originally placed flush but is now seated below the surface, or drops below the surface under load, the filler must be corrected. The means of correction will depend upon the cause of the recess.

TYPICAL CAUSES AND CORRECTION
If a filler has dropped in a saw cut joint, it is almost always a sign of improper filling procedures. For example:

A. A compressible backer rod was used below the filler.

B. The filler was placed over dirt and debris.

C. Too much sand was used and was not absorbed by the liquid filler.

CORRECTION:

The only solution is to totally remove the filler and all other material/debris in the joint. After thoroughly cleaning the joint it should be properly refilled in accordance with published instruction sheets. Any edge spalling that has occurred should be corrected at the same time (see repair sheets R1, R2).

CONSTRUCTION JOINTS (FLUSH BULKHEAD FORMED)
The cause of depressed filler in construction joints is not as easily identified. Likely causes include:

A. The filler depth was less than the 2" specified in our literature and lost its bond to the joint wall.

B. The joint opening was so great that the filler lost bond.

CORRECTION:

The best correction is to totally remove the existing failed filler and replace with new filler a minimum of 2" deep.

A second option is to use the existing filler as a base for the new filler. This method should be used only if the filler can be driven down deep enough to make room for 1 1/2" of replacement filler.

PRECAUTIONS ON CORRECTION
It cannot be assumed that the inside walls of older joints are clean. Curing compounds, cleaners, oils or other foreign matter that would reduce adhesion must be considered as possible, if not likely. All interior walls of joints must be thoroughly treated by re-sawing the joint or sand-blasting to remove all traces of adhesion preventers and existing filler.

Treat the correction as you would joints on a new project. Follow all published instructions and Metzger/McGuire Repair Sheets.