Skip to main content

Historic Preservation - Technical Procedures

Spectitle:

Patching Holes In Granite

Procedure code:

0446509R

Source:

National Capitol Region Specifications

Division:

Masonry

Section:

Granite

Last Modified:

02/24/2012

Details:

Patching Holes In Granite



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 cementiti= ous 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 Precaution= s

         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&qu= ot; (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.<= br>
    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=AB 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 followi= ng
         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<= br>          cracking will be unacceptable.  Tho= se patches found
         unacceptable will be removed and refilled as directed by
         Contracting Officer.

                         END OF SECTION