Historic Preservation - Technical Procedures
- Dutchman Repair Of Marble
- Procedure code:
- National Capitol Region Specifications
- Last Modified:
- Dutchman Repair Of Marble
- Last Modified:
DUTCHMAN REPAIR OF MARBLE
A. This procedure includes guidance on repairing severely
cracked marble blocks using dutchman repair. This
procedure is also appropriate for large spalls in marble.
B. For guidance on making other marble repairs, see 04455-
03-R, 04455-04-R, 04455-05-R, 04455-08-R, 04455-20-R and
C. 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
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).
A. American Society for Testing and Materials (ASTM)
A. Product Data: Submit manufacturer's product data for
epoxy adhesives or resins, including mixing instructions
and precautionary handling instructions.
B. Samples: Submit samples of marble dutchman units.
Include full range of colors and textures required to
match existing stone. Submit samples of stainless steel
pins for patching.
1.04 QUALITY ASSURANCE
1. Contractor performing the work shall have a minimum
of 5 years experience in masonry restoration work
of the type described for this project.
2. If requested by the Owner, furnish a statement of
the experience and qualifications of the firm and
of the key personnel who will work on this project.
Include the names and addresses of successful
projects completed, and for each, the name and
address of the owner and the architect.
1.05 DELIVERY, STORAGE AND HANDLING
A. Packing and Shipping: Deliver stone materials to the
project site in undamaged condition.
B. Storeage and Protection:
1. Store and handle stone to prevent their
deterioration or damage due to moisture, extreme
temperature changes, contaminants, breakage,
chipping or other causes.
2. Do not use pinch or wrecking bars to move or place
stone. Lift stone with wide belt slings where
possible. Use wood rollers to move stone
1.06 PROJECT/SITE CONDITIONS
A. Environmental Requirements: The work is to be executed
only when the air and surface temperature is 40 F and
rising, or less than 90 F. No pointing or patching is to
be executed when the temperature is 45 F and falling, or
when freezing temperatures are expected within 48 hours.
A. Jahn Restoration Mortars
B. Sika Corporation
A. Marble for replacement marble pieces and dutchman repairs
to match existing marble type, color and finish,
complying with ASTM C503. Size of replacements and
dutchman pieces shall be as required by field conditions.
B. Reinforcement/Anchors: Stainless steel type 302/304 3/8"
in diameter threaded rods, length as required.
C. Cementitious patching material such as "M70 Stone
Restoration Mortar" (Jahn Restoration), or approved
D. Epoxy grout: High-modulus, low viscosity, high strength
epoxy grouting/sealing/binder adhesive such as "Sikadur
35, Hi-Mod LV" (Sika Corporation), or approved equal.
E. Clean, soft cloths
F. Clean, potable water
A. Stiff fiber bristle brushes
B. Stiff wire bristle brushes
F. Spray bottle
G. Masonry drill
A. Protection: Protect existing adjacent materials during
the execution of the work. Provide necessary protection
and conduct work procedures to avoid damage to doors,
windows, flashing, roofing and other existing material
3.02 ERECTION, INSTALLATION, APPLICATION
A. Carefully remove loose stone fragments. Reuse all pieces
of spalled stone which are in sound condition without
serious cracks or flaws.
B. Clean any exposed metal anchors of all corrosion by
scraping and brushing with a stiff wire bristle brush.
Replace any unsound anchors as necessary with new
stainless steel anchors of approximate size and shape to
match existing. Bed new anchors in epoxy grout.
C. For resecurring small fragments, see 04455-21-R for
D. For larger fragments, square off the portion of spalled
stone for replacement with dutchman repair. Remove dust
and debris from cavity and fragments using a stiff fiber
E. Fit the dutchman for size.
F. For dutchman larger than 4" by 4" by 1", additional
reinforcement may be required.
1. Drill holes (size determined by size of
reinforcement selected) into both the sound stone
and the dutchman.
2. Inject adhesive into the holes and set stainless
steel pins into the holes.
G. Coat abutting surfaces of the stone with epoxy adhesive,
and secure the stone dutchman in place until the adhesive
H. Clean any residual adhesive from the edges using a clean
soft cloth. Wet the stone with clean, potable water and
fill any chipped areas and edges with patching mortar.
Avoid featheredging. Tool surface level with surrounding
stone. Keep mortar damp (80%-90% RH) for 72 hours or
END OF SECTION