Aluform De-Shuttering – Methods

 

Aluform De-Shuttering – Methods, Safety & Quality Control (As per IS Standards)

Aluform (Aluminium Formwork System) is widely adopted in high-rise and mass housing because it ensures high speed, dimensional accuracy, superior finish, and monolithic strength.
However, unsafe or early de-shuttering can cause cracking, honeycombing, deformation, accidents, and structural failure.
Therefore, Indian Standards (IS) provide guidance on timing, safety, stability, inspection, and quality during formwork removal.

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1️⃣ Relevant Indian Standards for Aluform De-Shuttering

Following standards should be considered during planning and execution:

• IS 456:2000 – Plain & Reinforced Concrete Code

  • Clause 11.3 — Stripping time of formwork

  • Clause 13 — Concrete curing & protection

• IS 3696 (Part 1 & 2) – Safety in Construction: Scaffolds & Working Platforms / Ladders

• IS 4082 – Storage & Handling of Construction Material (Useful for stacking & handling Aluform)

• IS 1200 (Part 5) – Formwork tolerances (good practice reference)

⭐ Always follow Project Specification + Consultant approval in addition to IS Code guidance.

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2️⃣ De-Shuttering Time Requirement (As per IS 456:2000, Clause 11.3.1)   

De-shuttering depends on:
✔ Concrete Grade
✔ Temperature & Curing
✔ Member Type
✔ Structural Loading

Minimum Formwork Removal Time (IS 456 Table – Recommended Values)

Structural Member	Minimum Time (Normal Weather)
Vertical sides of walls, columns & beams	16 – 24 hours
Slab soffit (props left under)	3 days
Beam soffit (props left under)	7 days
Props for Slab up to 4.5 m span	7 days
Props for Slab over 4.5 m span	14 days
Props for Beams & Arches up to 6 m span	14 days
Props for Beams & Arches over 6 m span	21 days

Strength-Based Requirement

IS 456 also emphasizes that:

• Concrete must gain minimum 70% of design strength before major de-shuttering.

• Cube test report should be verified before stripping.

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3️⃣ Aluform De-Shuttering Method (As per IS-Guided Good Practice)

A. Pre-De-Shuttering Checklist

Before removing formwork, ensure:

✔ Required stripping time completed (as per IS 456)
✔ Cube strength achieved (70% or above)
✔ Proper curing done (IS-456 clause 13 compliance)
✔ No cracks, deflection or deformation visible
✔ Temp supports stable
✔ Barricading & safety arrangements ready
✔ Engineer / QA-QC approval taken

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B. Step-By-Step De-Shuttering Procedure

Step 1 – Safety Preparation (IS 3696 Compliance)

• Isolate working zone

• Display warning boards

• Conduct toolbox talk

• Provide lighting

• Clear unwanted materials

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Step 2 – Remove Non-Load Bearing Forms First

Remove in sequence:

• External wall panels

• Beam side shutters

• Stair side shutters

⚠ No hammering allowed
Use only approved Aluform release tools.

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Step 3 – Remove Slab Panels Carefully

• Release with drop-head / pin system

• Keep props as per IS 456 duration

• Do not force panels

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Step 4 – Controlled De-Propping

• Remove props in phased manner

• Follow IS 456 prop retention rules

• Confirm upper floors are safe

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Step 5 – Cleaning & Storage (As per IS 4082)

• Clean using plastic / wooden scrapers

• Do not bend, weld or hammer

• Stack on flat stable surface

• Segregate damaged panels

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4️⃣ Safety Measures During Aluform De-Shuttering

A. Personal Protective Equipment (PPE)

Must as per IS 3696:

• Helmet

• Gloves

• Safety Shoes

• Goggles

• Reflective Jacket

• Harness (working at height)

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B. Site Safety Practices

• Close below working area

• No movement under work zone

• Use tag system

• Avoid de-shuttering during rain/wind

• Allow only trained workers

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C. Equipment Safety

• Use approved wrenches

• Mechanical lifting if heavy

• No gas cutting / welding on aluminium

• Inspect tools daily

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5️⃣ Quality Control During De-Shuttering

A. Post-Stripping Inspection (QA/QC)

Check for:

✔ Honeycombing
✔ Surface voids
✔ Cracks
✔ Dimensional accuracy
✔ Alignment / Plumb
✔ Level
✔ Surface finish

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B. Dimensional & Finish Tolerances

(Refer IS 1200 Good Practice Guidance & Project Specs)

• Verticality tolerance ±5 mm

• Level tolerance ±5 mm

• No structural cracks permitted

• Honeycomb not acceptable

• Repair immediately if found

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C. Rectification Measures

• Minor defects → polymer mortar repair

• Honeycombing → remove loose concrete & repair with approved repair mortar

• Severe defects → Consultant approval + NCR

• Maintain repair records

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6️⃣ Documentation Requirements

Maintain following records:

📌 Cube Test Report
📌 De-Shuttering Checklist
📌 Safety Permit / Toolbox Talk
📌 QA/QC Inspection Report
📌 NCR / Corrective Action Records

Good documentation improves transparency, audit compliance & safety reliability.

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7️⃣ Common Mistakes to Avoid

❌ Removing form before IS time limits
❌ Ignoring cube strength
❌ Hammering aluminium panels
❌ Allowing people below working area
❌ No barricading
❌ Poor stacking damaging panels

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Conclusion

Aluform de-shuttering is a critical structural & safety operation.
Following IS 456 stripping guidelines, IS 3696 safety norms, IS 4082 handling rules, and strong QA/QC discipline ensures:

✔ Structural safety
✔ High-quality finish
✔ Zero accidents
✔ Faster progress
✔ Reduced rework
✔ Long-term durability

Disciplined execution = Safe Structure + Quality Construction 👍