Daraweld C - Consumer Information - BuildSite.com

J O B A N A L Y Z E R 

Product Usage 

SOLUTION 

PROBLEM 

Badly Pitted, 

Worn, Broken 

Soft, Punky, 

Scaly, Friable 

Covered with 

Grease, Oil, 

Foreign Matter 

Extremely 

Porous 

Smooth 

and Dense 

Newly Placed, 

Clean and Sound 

DARAWELD ® 

Masonry 

C 

Bonding Agent for Masonry and Concrete Repair 

WIRE BRUSH 

only in 

extreme cases 

Application Information 

BONDING AGENT FOR CONCRETE 

WASH WITH 

DETERGENT 

AND RINSE 

ACID ETCH 

AND 

RINSE 

PAINT OR 

SPRAY WITH 

Daraweld C 

SOAK WITH 

WATER 

if dry 

SCRUB IN 

Daraweld C 

GROUT 

LEVEL WITH 

GROUT OR 

TOPPING MIX 

X X X X X X 

X X X X X X 

X X X X X 

X 

X 

X X X X X 

X X X 

X X X 

With Daraweld C, not all concrete surfaces in need of repair have to be chipped or scarified. Daraweld C patches can be feather-edged. Daraweld C 

cuts back on labor and preparation time – yet gives bonded repair – thoroughly dependable through the years of wear, weather, and moisture. 

GENERAL REPAIR WORK METHOD MATERIALS 

Shallow Patching and Thin Resurfacing 

(not more than 1 ⁄2 in. deep) of Worn, Broken, 

Scaled or Spalled Concrete Surfaces 

Steps, Sidewalks, Driveways, Floors, Walls, 

Ramps, Roads, Bridges, Abutments 

Bonding Grout for Thick Patches and 

Overlays 

Same applications as above and to bring 

Highway Sections up to Grade 

Filling Fine Cracks 

Walls, Floors, Pavements, Structures, 

Concrete Products 

Repairing Wide Cracks 

Same applications as above. 

Thoroughly pre-mix cement and sand. In a separate 

container combine Daraweld C with an equal quantity 

of water and add to the cement/sand mixture. Mix to a 

creamy consistency. Do not overmix. Scrub this bonding 

layer onto surface with a stiff bristle brush of corn broom 

in a layer no more than 1 ⁄8 in. thick. Level with remaining 

material while bonding layer is still soft and plastic. 

Follow same method as above for bonding layer. Level 

with plain cement mortar or concrete topping and finish 

to desired grade. Add air entraining admixture to topping 

mix for maximum durability if overlay will be exposed to 

freezing and thawing. 

Mix materials until blended into thin paste. On horizontal 

surfaces, pour paste into crack to overflowing and cut off 

with trowel when stiff. On vertical surfaces, paint cracks 

with paste, then fill with grout as prescribed above for 

Shallow Patching. 

Paint crack with straight Daraweld C, making sure coating 

extends beyond edges. Scrub in grout with stiff brush. Fill 

with remaining material and finish with trowel. 

*Water content specified for above application is approximate. Add more water where necessary for proper consistency. 

1 part Daraweld C 

5 parts Cement 

2 parts Mason’s Sand 

1 part Water* 

Same materials and 

proportions as above. 


1 part Cement 

1 part Water* 


1 part Cement 

1.5 parts Mason’s Sand 

0.5 part Water*

BONDING APPLICATIONS 

Bonding Concrete to Asphalt 

Bonding Construction Joints 

FLOOR APPLICATIONS 

Protecting Floors Against Mild Acid Attack 

Laundries, Dairies, Degreasing Pits, etc. 

Non-Skid Floor Treatments 

Sidewalks, Patios, Garages, Swimming Pools, 

Industrial Floors, Aircraft Hangers 

Scrub standard Daraweld C grout onto asphalt surface 

with stiff brush or corn broom. For thick overlay, top with 

mortar or concrete topping while grout is still plastic. 

When dry, surface can be painted with cement paint. 

(See “Painting” section that follows). 

When walls or slabs are poured in stages, apply standard 

Daraweld C grout over the surface of each pour to obtain 

integral bond with subsequent pours. 

For porous floors exposed to acids, corrosive agents, cleaning 

fluids. Bring the mixture to a paint consistency. Apply 

with a stiff broom or spray equipment. For best results, 

apply at least two coats, allowing 24 hours between coats. 

Apply with scrubbing brush, then swirl to get a rough 

finish. This application has been extremely successful in 

providing safe, sure footing on surfaces normally slippery 

when wet. 




1 part Water* 

Same materials and 

proportions as above. 


5 parts Lumnite Cement 

2.5 parts Portland Cement 

1 part Water* 

Caution: See Note Below. 




1.5 parts Water* 

Dustproofing Floors Pour on and distribute evenly with squeegee. Sop up 1 part Daraweld C 

puddles with cloth or sponge, since a heavy concentration 

of the material may seal soft. Floor must be closed to 

traffic for 24 hours to allow for thorough drying. 

For porous surfaces a second coat is recommended. 

2 parts Water* 

Leveling for Floor Tile 

Before Application of Vinyl and Asphalt Tile 

Anchoring Nailing Strips to Concrete Floors 

Before Application of Wood Finish Flooring 

Layering Plaster Floor Tile 

On Wood or Concrete Floors 

WALL APPLICATIONS 

Apply Daraweld C grout and level to desired grade. Allow 

24 hours for curing. Apply tile cement directly on new 

surface, lay tile. 

With straight Daraweld C, glue tapered wooden strips, 

narrow edge up, to concrete floor. Apply Daraweld C 

grout between strips and level. 

To adhere plaster tile, brush or squeeze Daraweld C as 

received on wood or concrete surface. Prime with dilute 

Daraweld C first if surface is dusty and porous concrete. 









Straight Daraweld C 

Repairing Walls With Gunite Mortar The use of Daraweld C increases adhesion of Gunite 1 part Daraweld C 

applications. When added to the mix water, Daraweld C 

also tends to decrease rebound during application, and 

allows quicker finishing. To mix Daraweld C and water, 

use a large open drum. Supply gun direct from drum. 

1 part Water* 

An alternate method is to first spray or brush surface with 

a 1:1 solution of Daraweld C and water. Apply Gunite 

mortar as usual, while bonding coat is still tacky. 

Patching Stucco Walls Scrub in Daraweld C paste, and level with stucco mortar. 1 part Daraweld C 

If entire wall is to be resurfaced, scrub in Daraweld C 5 parts Cement 

grout and apply finish mortar coat while grout is still 

tacky. If wall is to be repainted, refer to “Painting” section 

which follows. 

1 part Water* 

Steamproofing Concrete Block Walls 

Commercial Laundries, Car Washes, 

Poultry Processing Plants, etc. 

METHOD MATERIALS 



A two-coat application of Daraweld C paste will prevent 

steam and water from penetrating concrete block walls 

in commercial and industrial processing areas. 

Each coat calls for different proportions of materials. 

Both applications should be scrubbed on, with a 24-hour 

interval between coats. 

First coat: 




Second coat: 


1 part Cement 

1 part Water* 


Note: Check setting time of Lumnite-Portland cement combination before making batch. Set may vary from very fast to very slow with 

different brands of cement.

MORTAR 

Additive for Paving Mortar 

PAINTING & FINISHING 

Daraweld C is widely used as an admixture in mortar for 

setting and grouting common or architectural brick used 

for patios, plazas, walkways and similar placements. The 

use of Daraweld C provides excellent adhesion to the 

setting bed and a strong and durable mortar joint. Gray or 

white Portland cement with or without mineral oxide 

color or prepared masonry cements may be used to effect 

matching or contrasting color. Mixed as described, the 

mortar (grout) is spread and leveled on the prepared 

substrate and the brick set thereon. After the setting bed 

has hardened, the joints between the bricks can be filled 

with mortar containing Daraweld C. 


1 part Water* 

Cement, lime, sand proportions 

to conform to standard 

ASTM specifications. 

Mix grout, color as desired with mineral oxide. Apply 

with stiff brush to 1 Redressing and Coloring Concrete Floors 1 part Daraweld C 

⁄16 in. thickness, or just thick enough to 5 parts Cement (white) 

prevent sand from rolling under trowel. Finish with 2.5 parts Mason’s Sand 

steel trowel. 

As req. Color 

1 part Water* 

Finishing Concrete Block Walls Use stiff bristle brush, apply with scrubbing action. 1 part Daraweld C 

Increasing the Daraweld C content in the mix will give a 5 parts Cement 

dense, semigloss texture that can be colored or painted. 10 parts Mason’s Sand 

One coat is sufficient except where severe water seepage 

occurs. (See “Waterproofing” section that follows.) 


Painting Concrete Blocks, Brick or Sandstone Mix dry and wet ingredients separately. Add dry mixture to 1 part Daraweld C 

liquid to get paint consistency. Add color for desired color. 5 parts Cement 

Proper proportions of gray and white Portland cement will 10 parts Mason’s Sand 

give matching color for concrete blocks. Apply with 2 parts Water* 

scrubbing action. Caution: Do not attempt to apply cement 

paint over earlier coat of oil paint. 

As req. Color 

Striping Asphalt Surfaces The addition of Daraweld C to white cement mortar 1 part Daraweld C 

produces a highly durable striping material. Mix dry 5 parts Cement (white) 

and wet ingredients separately. Combine mixtures just 2.5 parts Mason’s Sand 

before application. Scrub onto clean asphalt surface. 1 part Water* 

As req. Color 

SPECIAL APPLICATIONS 

Repairing and Making Special Joints in 

Concrete Pipe 

Preventing Corrosion and Seepage of 

Concrete Pipe 

Daraweld C can be used to patch broken or specially 

sectioned pipe at the casting plant and in the field. Mix and 

scrub thin paste, nesting the broken sections together until 

paste is cured. Small breaks and/or cracks can be filled with 

this same paste mix, with 2 parts mason’s sand added. 

Daraweld C’s acid-alkali resistance makes it an excellent 

protective compound. It was successfully used to stop 

seepage of corrosive waste through concrete pipe at the 

Atomic Energy Commission installation at Oak Ridge, 

Tennessee. 



1 part Water* 


3 parts Lumnite Cement 


1 part Water* 

Caution: See Note Page 2. 

Daraweld C is ideal for repairing the holes created by 

removal of test specimens. Core test holes of 5 in. diameter, 

repave, with a 17 Plugging Core Test Holes Add 20% Daraweld C by 

weight of specified cement. 

⁄8 in. Daraweld C patch, showed no break Reduce water equal to vol- 

in the bond after 50 cycles of freezing and thawing. ume of Daraweld C added. 

Scrub on Daraweld C mixture. A patch in the form of a 

band of belt approximately 3 ft wide and 1 Repairing Leaking Construction Joints 1 part Daraweld C 

⁄4 in. thick has 3 parts Cement 

worked especially well around leaking construction joints 1.5 parts Mason’s Sand 

in concrete tanks. 

0.5 part Water* 

Reclaiming Prestressed Concrete Prestressed concrete slabs and beams damaged during 1 part Daraweld C 

handling or by other causes (fire included) can be repaired 5 parts Cement 

with Daraweld C. Just scrub on standard Daraweld C 2 parts Mason’s Sand 

grout. If necessary, trowel on a thicker coat at cracks, 

corners or surface indentations. Daraweld C can be used 

to fill holes for eyebolts or hooks attached on the site. 

1 part Water* 

WATERPROOFING 

Waterproofing Coating 

Exterior Masonry Above and Below Grade, 

Cellar Floors, Machinery Pits, Ceramic Wash 

Basins, etc. 





Two or three coats of Daraweld C grout are required 

for successful waterproofing applications. Mix materials 

to brushable consistency. Scrub each coat into surface 

with stiff brush. Apply second and third coats at 24-hour 

intervals. To stop water seepage through cellar floors, 

machinery pits, etc., install a sump pit to drain off standing 

water. Repair bad spots with hot patches. Sop up all 

puddles before applying grout. 





1 part Water*

Mixing Grout 

Thoroughly pre-mix cement and fine 

mason’s sand. In a separate container 

combine Daraweld C with a recommended 

quantity of water and add to 

the cement-sand mixture. Even when 

the grout is machine-mixed, which we 

recommend, the dry and wet ingredients 

should be mixed separately. 

Daraweld C grout should have the 

consistency of heavy cream. Do not 

overmix, or whip air into the grout. 

Overmixing can cause blistering in 

surface coatings. Mix until ingredients 

appear to be normally blended. 

Use enough Daraweld C in plastic 

mix. Quantities smaller than specified 

will lessen bond strength. 

Make up in small batches. Daraweld C 

grout will stiffen and become hard to 

apply within 30 to 40 minutes after 

mixing. Make up only what you can 

use in this period. Do not retemper. 

Applying Grout 

Scrub Daraweld C bonding grout 

onto surface with a stiff bristle brush 

or broom in a layer not more than 

1 ⁄8 in. thick. Work briskly to break 

through surface tensions and 

entrained air. In thin patches less than 

1 ⁄2 in. deep, level with Daraweld C 

grout while bonding layer is still soft 

and plastic. 

Topping Mixes 

Visit our web site at: www.graceconstruction.com printed on recycled paper 

W. R. Grace & Co. - Conn., 7221 West Parkland Court, Milwaukee, WI 53223 Tel: (414) 354-4400 Fax: (414) 354-5088 

DARAWELD C, DAREX AEA and DARAVAIR are registered trademarks of W. R. Grace & Co. - Conn. 

Limit the amount of water used in 

topping mixes. A dry, low water 

content mix will result in a dense, 

hard floor surface. 

Use maximum-size aggregate 

consistent with depth of overlay. 

Apply and level topping material 

while Daraweld C bonding layer is 

still soft and plastic. 

Topping should be dry enough to 

require considerable tamping for compaction. 

The tamping will also provide 

better intimate contact between the 

bonding grout and the topping. Screed 

a little high for compaction. 

Don’t forget that straight Portland 

cement mortar or concrete toppings 

exposed to freezing and thawing 

should be properly air entrained 

with Darex AEA ® or Daravair ® . 

No entrained air is required for the 

Daraweld C bonding grout. 

Finishing 

In thin resurfacing work, wood 

floating immediately after screeding 

will make for a stronger bond and 

minimum shrinkage. 

For a smooth surface, a single pass 

with a steel trowel is recommended. 

Do not overfinish. Excessive steel 

troweling will cause desiccation, 

or drying-out. 

The tamped topping mixes used in 

thicker overlays can be finished 

normally. 

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate and is offered for the users’ consideration, 

investigation and verification, but we do not warrant the results to be obtained. Please read all statements, recommendations or suggestions in conjunction with our 

conditions of sale, which apply to all goods supplied by us. No statement, recommendation or suggestion is intended for any use which would infringe any patent or 

copyright. W. R. Grace & Co. - Conn., 62 Whittemore Avenue, Cambridge, MA 02140. In Canada, Grace Canada, Inc., 294 Clements Road West, Ajax, Ontario, 

Canada L1S 3C6. 

This product(s) may be covered by patents or patents pending. Copyright 2001. W. R. Grace & Co. - Conn. MP-054B Printed in USA 12/01 FA/GPS/3M 

Hydration and Curing 

The patch area must be damp. 

A too-dry surface will draw water 

out of the grout too swiftly to allow 

proper hydration of the cement. 

Excessive troweling or finishing on 

thin patches or overlays will prevent 

proper curing. 

Proper curing of the new patch or 

overlay will greatly improve its 

compressive strength and abrasion 

resistance, and will prevent excessive 

shrinkage. 

Surface Cleaning 

Oil and grease should be removed by 

washing with a strong solution. Sand 

blasting and water blasting, chipping 

or scarification have been found to 

be acceptable methods to remove 

unsound surface mortar. A thorough 

rinse with clear water prior to the 

application of the Daraweld C bonding 

grout is recommended. If muriatic 

acid is used to remove unsound 

surface mortar, before applying the 

Daraweld C overlay the area must be 

thoroughly rinsed with clear water 

to remove all of the acid. Safety 

procedures as recommended by the 

manufacturer of the acid should be 

strictly adhered to.

Daraweld C - Consumer Information - BuildSite.com

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