How to Repair a Cracked Pool Surface?Updated a month ago

Cracks in your pool’s surface aren’t just unsightly—they can lead to leaks, structural damage, or cuts on swimmers. Here’s how to fix cracks in plaster, vinyl, and fibreglass pools.

1. Plaster Pool Cracks

Causes: Ground movement, poor curing, or age.

Repair Steps:

1. Drain the pool (if crack is deep or leaks). IMPORTANT: Seek help of a professional before draining pool

2. Chip out the crack: Use a chisel to widen it into a V-shape (removes loose material).

3. Clean debris: Rinse with water and let dry.

4. Apply bonding agent: Brush a layer into the crack.

5. Fill with plaster mix: Use pool-grade plaster repair compound, smooth with a trowel.

6. Cure: Keep damp for 48 hours (cover with wet hessian).

7. Acid wash (optional): Blend the repair with the existing surface.

Pro tip: For hairline cracks, you can use an underwater pool repair kit like CORKIT / Aqua Fix-it without draining.

2. Vinyl Liner Cracks or Tears

Causes: Punctures, UV degradation, or shrinking.

Repair Steps:

1. Locate the tear: Look for wrinkles, bubbles, or visible splits.

2. Clean the area: Use rubbing alcohol to remove oils.

3. Apply patch:

   • Cut a patch 5–10cm larger than the tear from a vinyl repair kit.

   • Apply adhesive to both patch and liner, press firmly, and roll out air bubbles.

4. Wait 24 hours before refilling.

Note: Large tears (>15cm) may require partial liner replacement.

3. Fibreglass Pool Cracks

Causes: Impact damage, ground movement, or flexing.

Repair Steps:

1. Sand the crack: Use 80-grit sandpaper to roughen the area.

2. Clean with acetone: Remove dust and grease.

3. Fill with gelcoat/resin:

   • Mix fibreglass repair resin with catalyst.

   • Apply with a plastic spatula, layering until slightly raised.

4. Sand smooth: Once cured, sand with 120–220 grit.

5. Polish: Use marine-grade polish to restore shine.

For structural cracks: Reinforce with fibreglass matting before resin.

When to Call a Pro

• Structural cracks (deep or spiderweb patterns in plaster/fibreglass).

• Multiple leaks suggesting ground instability.

• Vinyl liner replacement (DIY risks improper fitting).

Prevention Tips for Aussie Pools

• Control ground moisture: Install drainage to prevent soil movement.

• Avoid sharp objects: No glass or metal toys in vinyl pools.

• Balance water chemistry: High pH or calcium hardness weakens plaster.

• Shade covers: Protect vinyl/fibreglass from UV damage.

Final Tip: Small cracks are easier (and cheaper) to fix early—don’t ignore them!