FORSPEC FORBUILD 100 grey concrete repair mortar in a 20 kg bag
FORSPEC FORBUILD 100 grey concrete repair mortar in a 20 kg bag
Forspec

FORSPEC FORBUILD 100 Concrete Repair Mortar

$87.50 AUD
$87.50 AUD
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FORSPEC FORBUILD 100 is a fibre-reinforced, polymer-modified cementitious repair mortar for restoring damaged reinforced concrete. Its thixotropic consistency supports horizontal, vertical and overhead patching, edge rebuilding, ramping and falls correction. Microsilica and corrosion inhibitors provide low permeability and help protect embedded reinforcement in aggressive environments, including marine structures, bridges, retaining walls and water-retaining structures. Mixed with clean water and applied by hand or wet-spray, it bonds to correctly prepared concrete and cleaned reinforcement. Substrate preparation, bonding and curing must follow the current TDS.
  • Water-mixed single-component mortar
  • Fibre reinforcement and polymer modification
  • Thixotropic placement on walls and soffits
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  • Fibre-reinforced, polymer- and microsilica-modified cementitious mortar
  • Corrosion inhibitors help protect embedded reinforcement
  • Thixotropic consistency for vertical and overhead placement
  • 56 MPa compressive strength at 28 days (manufacturer characteristic value)
  • Low permeability for repairs in aggressive environments
  • Hand or wet-spray application
  • 1. Remove weak, damaged or contaminated concrete. Cut repair edges square at least 5 mm deep; do not feather-edge. Mechanically roughen horizontal substrates and remove dust, laitance, grease and standing water.
  • 2. Expose corroded reinforcement and clean to bright metal. Allow at least 10 mm mortar behind and over reinforcement. Rectify structural cracks using the specified FORSPEC epoxy repair system; stop active leaks before placing mortar.
  • 3. Pre-wet concrete to saturated surface dry, with no free water. Revision 2 specifies ACTFLEX 300 primer. Highly absorbent substrates require two coats: allow the first to dry and place mortar while the second is tacky. Follow current FORSPEC instructions for the actual substrate.
  • 4. Where the slurry bonding coat is used, mix 1 part ACTFLEX 300 : 1 part clean water : 3 parts FORBUILD 100 powder. Brush firmly into the substrate, allow 10 minutes, and place mortar while tacky. Renew any slurry that dries.
  • 5. For hand application, measure 3.2–3.4 L clean water per 20 kg bag. Add powder to water; mix at 400–600 rpm for 3–4 minutes, rest 1–2 minutes and re-mix briefly. Do not add cement, lime, gypsum or other additives, exceed the water dose or re-temper stiffened mortar. The TDS separately permits up to 3.6 L for spray/pump application; confirm that exception with FORSPEC before use.
  • 6. Place within the 60-minute pot life at 25°C and 50% RH, onto the tacky primer/slurry. Compact firmly without voids. Horizontal layers: 3–100 mm, maintaining squared repair edges. For vertical/overhead work follow the application section's 5–40 mm passes to 100 mm total. The technical table also lists a 3 mm minimum: confirm with FORSPEC before specifying thinner vertical/overhead passes.
  • 7. Roughen and dampen fully hardened previous layers. Finish as the mortar firms; lightly broom-finish where later adhesives or coatings require a key.
  • 8. Protect from rain, frost, sun and rapid drying. In drying conditions mist for at least 1 hour immediately after finishing. Above 30°C and below 50% RH use damp hessian or plastic coverings for the first 24 hours. Maintain curing for at least 48 hours. Do not use curing compounds.
  • 9. Allow at least 24 hours before light foot traffic and at least 7 days before FORSPEC coatings, with moisture verified, at 25°C and 50% RH. Extend for adverse conditions and thickness; comply with the selected coating's requirements.
  • 10. Clean tools immediately with water; remove hardened material mechanically. Control cement dust and skin/eye contact and read the SDS before use.
  • Grey powder; 20 kg bag
  • Mixing water: 3.2–3.4 L per bag for hand application
  • Pot life: 60 minutes at 25°C and 50% RH
  • Initial/final set: 75/120 minutes at 25°C and 50% RH
  • Consumption: 1.85 kg/m²/mm; approximately 11 L mixed yield per bag
  • Horizontal build: 3–100 mm per layer; cut repair edges at least 5 mm deep, with no feather edging
  • Vertical/overhead: use 5–40 mm passes as specified in the application instructions, to 100 mm total
  • Application temperature: 5–35°C, ambient and substrate
  • Cure for at least 48 hours; no curing compounds
  • Coating: minimum 7 days with moisture verified, at 25°C and 50% RH
  • Shelf life: 12 months unopened, stored dry
  • EN 1504-3 performance data reported by manufacturer; no independent classification certificate supplied
Technical Data Sheet Installation Guide Warranty Information

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Technical Specifications

Key technical properties of this product. Refer to the Technical Data Sheet for complete installation and performance information.

ClassificationFibre-reinforced, polymer-modified cementitious structural repair mortar
Mixing Ratio3.2–3.4 L clean water per 20 kg powder for hand application
Coverage1.85 kg/m²/mm; approximately 1.1 m² per 20 kg bag at 10 mm
Suitable SubstratesSound, prepared concrete and cleaned steel reinforcement
CuringMinimum 48 hours; water misting/protective coverings only
Reinforcement CoverMinimum 10 mm mortar behind and over cleaned reinforcement
View Technical Data Sheet

FORBUILD 100 FAQs

What is FORBUILD 100 used for?
FORBUILD 100 is a cementitious repair mortar for damaged reinforced concrete, including patch repairs, edge rebuilding, ramps, falls correction and horizontal, vertical or overhead repairs. The TDS includes marine structures, bridges, retaining walls and water-retaining structures.
How much FORBUILD 100 do I need?
Allow 1.85 kg of powder per m² per mm of repair thickness. Calculate bags as area (m²) × average thickness (mm) × 1.85 ÷ 20, then allow for site wastage and round up to whole bags. A 20 kg bag covers approximately 1.1 m² at 10 mm. The area calculator on this listing is for 10 mm thickness only; variable-depth patches require a volume-based estimate.
How much water is required per bag?
For hand application, mix each 20 kg bag with 3.2–3.4 L of clean water. Add powder to water and mix at 400–600 rpm for 3–4 minutes, rest for 1–2 minutes, then re-mix briefly. Pot life is approximately 60 minutes at 25°C and 50% RH. Do not add other additives or re-temper stiffened mortar.
Does FORBUILD 100 require a primer?
The current Revision 2 TDS specifies ACTFLEX 300 over the prepared substrate. On highly absorbent substrates, apply two coats and place mortar while the second remains tacky. It also describes a bonding slurry of 1 part ACTFLEX 300, 1 part clean water and 3 parts FORBUILD 100 powder. Place mortar while the primer or slurry remains tacky; renew a dried slurry coat.
When can FORBUILD 100 be coated?
Maintain curing for at least 48 hours using water misting or protective coverings; do not use curing compounds. The TDS gives a minimum 7 days before FORSPEC membranes or coatings, with moisture verified, at 25°C and 50% RH. Lower temperatures, higher humidity and thicker repairs extend the period. Follow the selected coating's substrate moisture and preparation requirements.

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