Honolulu Hawaii Spall Repair Service

At Seal Masters of Hawaii we can provide you with many concrete services including our spall repair.

What is Spall Repair?

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Concrete spalling is a fragment or chip removed from the face of a stone or masonry surface by a blow or by actions of the elements. A spall is also known as a section of concrete that is separating or has been separated from the original structure.

Concrete's high level of alkalinity creates a thin, invisible, protective oxide film to form on the steel. When sodium chloride or calcium chloride exists, along with Hawaii's moisture and oxygen, carbonation occurs, breaking down the protective film; thus causing corrosion to begin. As corrosion increases or builds up inside the concrete, tremendous force is exerted on the concrete. Cracking is first observed and if not properly repaired in a timely manner, larger sections of concrete begin to break away, resulting is spalling.

The most common causes of spalled concrete in Honolulu include 1) corrosion of reinforcing steel, 2) impact, 3) freezing and thawing of porous aggregate in a critically water saturated condition, and 4) alkali-silica reaction.

A spall in a concrete surface may be the result of localized distress or the symptom of a more widespread distress in the concrete element. In either case, an attempt should be made to determine the cause of distress prior to taking corrective action. This can easily be accomplished by retaining the services of a reputable architectural firm, engineering firm or contractor.

Spall repair is not a band-aid to a structure in distress; it is a complex engineering task with challenges substantially different from those associated with new construction. This intricacy increases with the age of a structure and the severity of deterioration. Trying to simplify the repair process could have potential technical, safety and economic implications. Techniques, such as Cathodic Protection most commonly used in Hawaii and elsewhere to protect steel and prevent corrosion should only be considered if specified by a reputable architect, engineer, consultant or if being installed by a contractor who is experienced and understands the installation process.

Standard practice for the repair of concrete spalls vary depending on the type of concrete element being repaired, cause and extent of damage, location of the spall and material selected. The repair material selection is typically based on such factors as properties of the repair material, Honolulu's climatic conditions, repair time frame, expected service life and cost. In general, a corrosion inhibiting polymer modified repair concrete should be used for spall repair projects.

The repair process generally includes 1) a physical inspection to document the details and extent of damages, 2) an assessment to determine the cause of distress, 3) the selection of repair materials, 4) the selection of an experienced contractor who specializes in concrete repair work. Once spall repairs are completed the structure or repaired areas should be protected with an elastomeric waterproof coating.

How We Do Our Concrete Spall Repair

  • Visually inspect and sound the concrete with a hammer to locate all spalled and cracked concrete.
  • Repair all spalls in accordance with the International Concrete Repair Institutes repair methods.
  • Use 15 pound jack hammer to remove the spalled concrete within the saw cut until reinforcing steel is fully exposed and the concrete is removed from around the rebar a minimum of 3/4".
  • Saw cut a 1/2" deep perimeter around each spalled area.
  • Remove rust from reinforcing steel with power wire wheel.
  • Clean spall cavity thoroughly and saturate existing concrete dry.
  • Treat rebar with Sika Armatec 110 Corrosion inhibiting epoxy.
  • In the event that the exposed reinforcing steel has lost more than 20% of its cross section, the affected rebar will be removed and new rebar will be spliced in place by drilling a 3" deep hole into the concrete and installing the new rebar into the hole with epoxy and then tie wire the new bar to the existing adjacent bar. The new bar must overlap the exisitng bar by 8" or half of its length.
  • Install Corrosion inhibiting polymer modified 5000 PSI Portland cement ASTM C150, Type 1 convertible cement. Add Acryl 60 manufactured by Thoro Systems Products and water to cement at a ratio of 4 to 1 (4 parts water, 1 part Acryl 60). Add 16 oz. per 80 lb bag of cement of Grace DCIS corrosion inhibiting to each mix.
  • Install Thorite Rapid Vertical into all vertical and overhead spall cavities and trowel to match adjacent profile.

Hawaii Concrete Crack Repair

  • Saw cut cracks open 1/4" wide by 1/4" deep.
  • Clean surface being sealed.
  • Install Primer.
  • Install backer rod or bond breaker tape, as required.
  • Install Sika self leveling sealant.
  • Repaint previously painted areas that are repaired.
  • Install Sika Self Leveling Sealant for horizontal surfaces and Sika Flex 1a for vertical and overhead surfaces.


Seal Masters of Hawaii
80 Sand Island Access Road
Honolulu, Hawaii 96819 -- USA

Tel: (808) 841-7602
Fax: (808) 842-6546