PATCHING HOLES IN GRANITE


PART 1---GENERAL

1.01 SUMMARY

     A.   This procedure includes guidance on patching holes in
          granite using a mortar patch and bonding agent.  This
          procedure is appropriate for use on holes measuring less
          than 3 cubic inches.  For cementitious patch repair, see
          also 04465-28-R.

     B.   See 01100-07-S for general project guidelines to be
          reviewed along with this procedure.  These guidelines
          cover the following sections:

          1.   Safety Precautions

          2.   Historic Structures Precautions

          3.   Submittals

          4.   Quality Assurance

          5.   Delivery, Storage and Handling

          6.   Project/Site Conditions

          7.   Sequencing and Scheduling

          8.   General Protection (Surface and Surrounding)

          These guidelines should be reviewed prior to performing
          this procedure and should be followed, when applicable,
          along with recommendations from the Regional Historic
          Preservation Officer (RHPO).


PART 2---PRODUCTS

2.01 MANUFACTURERS

     A.   Sika Corporation
          201 Polito Ave.
          Lyndhurst, NJ  07071
          201/933-8800

2.02 MATERIALS

     A.   Repair mortar is to match the original mortar mix. 
          Laboratory test results will serve as standard for mix
          proportions and color.

     B.   Adhesive for bonding fresh mortar to hardened material,
          such as "Sikadur Hi-Mod Adhesive" (Sika Corporation), or
          approved equal.

     C.   Clean, soft cloths

     D.   Clean, potable water

2.03 EQUIPMENT

     A.   Stiff natural-bristle brush

     B.   Chisel

     C.   Rubber mallet

     D.   Trowel

2.04 MIXES
     
     A.   Measure materials by volume or equivalent weight.

     B.   Do not measure by shovel.  Use known measure.

     C.   Mix ingredients in clean mechanical batcher for 3-5
          minutes.

     D.   Let mortar sit for 20 minutes prior to use, to allow for
          initial shrinkage.  Use mortar within 1« hours of initial
          mixing.


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

     A.   Remove previous mortar patches.  Clean all stone areas
          and wall surfaces to be repaired of all debris, dust,
          oil, dirt and grime by brushing with a stiff, natural-
          bristle brush.

     B.   Carefully cut back damaged granite using a chisel and
          mallet.  Locate cuts in the existing granite to enable
          the least conspicuous patch and give the straightest,
          most uniform and smallest joint possible.  Remove dust
          and debris with a stiff, natural bristle brush.

     C.   Brush coat the stone surface with adhesive following
          manufacturer's instructions.

     D.   Place patching mortar in layers no thicker than 3/4". 
          Roughen surface of each layer to provide key for the
          next.

     E.   Keep each layer damp (80 -90 RH) for 72 hours or until
          mortar is set.  In patches which are deep enough to
          require more than one application, coat each layer with
          adhesive prior to placing next layer.

     F.   Separation at the edges of the patch and hairline
          cracking will be unacceptable.  Those patches found
          unacceptable will be removed and refilled as directed by
          Contracting Officer.

                          END OF SECTION