Common Non Shrink Grout Site Mistakes
Non shrink grout is specifically designed to deliver high strength, volume stability, and reliable load transfer. However, on many construction sites, its performance is compromised due to incorrect practices rather than product defects. Understanding the most common non shrink grout site mistakes helps contractors, engineers, and site teams avoid failures, rework, and long-term structural issues.
1. Adding Excess Water During Mixing
One of the most frequent site mistakes is adding extra water to improve grout flow.
Mistake
- Workers add water to make grout easier to pour
- Water is estimated instead of measured
- Different batches have inconsistent water content
Impact
- Reduced compressive strength
- Increased shrinkage and cracking
- Bleeding and segregation
Correct Practice
- Always measure water accurately
- Follow recommended mixing ratios strictly
- Use flowable grout instead of adding water
2. Poor Surface Preparation
Inadequate preparation prevents proper bonding and grout flow.
Mistake
- Dust, oil, or laitance left on concrete surfaces
- Dry concrete absorbing water from grout
- Unclean anchor bolt pockets
Impact
- Loss of bond between grout and substrate
- Formation of voids at interfaces
- Reduced load transfer
Correct Practice
- Clean and roughen concrete surfaces properly
- Pre-wet concrete to saturated surface dry condition
- Ensure bolt holes and pockets are clean
3. Incorrect Grout Placement Method
Improper placement leads to air entrapment and voids.
Mistake
- Pouring grout from multiple sides
- Interrupted placement due to delays
- Vibrating grout like concrete
Impact
- Air pockets beneath base plates
- Honeycombing and internal voids
- Uneven support under load
Correct Practice
- Pour grout continuously from one side only
- Allow grout to flow naturally under the plate
- Avoid vibration and excessive rodding
4. Leaking or Weak Formwork
Poor formwork allows grout loss and uneven filling.
Mistake
- Unsealed formwork joints
- Flexible or poorly supported shutters
- No grout head or venting provision
Impact
- Loss of grout volume
- Voids beneath structural elements
- Surface honeycombing
Correct Practice
- Install rigid, leak-proof formwork
- Seal joints using foam or sealant
- Provide grout head and air vents
5. Inadequate Curing
Skipping curing is a common but serious error.
Mistake
- Leaving grout exposed to sun and wind
- No curing compound or moisture protection
- Stopping curing too early
Impact
- Shrinkage and surface cracking
- Lower final compressive strength
- Reduced durability
Correct Practice
- Start curing immediately after initial set
- Maintain curing for at least 3–7 days
- Protect grout from extreme weather
6. Early Loading of Grouted Elements
Applying load before strength gain damages grout internally.
Mistake
- Installing machinery too early
- Tightening anchor bolts before grout strength is achieved
- Ignoring specified curing time
Impact
- Micro-cracking inside grout
- Permanent deformation
- Loss of long-term load capacity
Correct Practice
- Wait until grout reaches specified strength
- Follow loading timelines from specifications
- Inspect grout before applying load
7. Using the Wrong Grout Type or Grade
Incorrect product selection leads to performance failure.
Mistake
- Using ordinary cement grout instead of non shrink grout
- Selecting low-grade grout for heavy loads
- Ignoring environmental and load conditions
Impact
- Excessive shrinkage and cracking
- Inadequate load transfer
- Premature grout failure
Correct Practice
- Select grout based on load and application
- Use factory-formulated non shrink grout
- Follow engineer and project specifications
How to Avoid Site Grouting Mistakes
- Train workers on correct grouting procedures
- Maintain strict supervision during grouting works
- Use written method statements
- Conduct inspections before and after grouting
Frequently Asked Questions (FAQ)
1. Are these mistakes common on construction sites?
Yes, most non shrink grout failures are caused by site practices rather than material defects.
2. Can these mistakes be corrected later?
Minor issues can be repaired, but major defects may require complete re-grouting.
3. Does non shrink grout forgive poor workmanship?
No, correct application is essential for performance.
4. Is supervision really necessary?
Yes, supervision significantly reduces grouting errors and rework.
5. Can following guidelines really prevent failure?
Yes, most grout failures are fully preventable with proper practices.
Raltro
Raltro is a construction materials knowledge platform focused on improving real-site workmanship and execution quality. By highlighting common non shrink grout site mistakes and explaining how to avoid them, Raltro helps engineers, contractors, and site teams reduce failures, improve grouting reliability, and achieve long-term structural performance through correct material handling and application practices.