Contact us

Fibreglass Waterproofing

Here’s a step-by-step guide to fiberglass waterproofing a surface such as a fishpond, water feature or wet area like a bathroom. This method is especially useful for creating a durable, seamless, and long-lasting waterproof membrane.

✅ Tools & Materials Needed

  • Fiberglass mat (chopped strand mat, typically 250–450g/m²)

  • Polyester resin or epoxy resin (polyester is more common for general waterproofing)

  • Hardener (MEKP for polyester resin)

  • Mixing container

  • Paint rollers & brushes

  • Scissors or utility knife

  • Safety gear (gloves, goggles, mask)

  • Sandpaper or grinder

  • Primer (if required by resin type or surface)

  • Acetone (for cleaning tools)

  • Topcoat (gelcoat, polyurethane, or acrylic waterproofing top layer)

🛠️ Step-by-Step Instructions

Step 1: Surface Preparation

  1. Clean the surface thoroughly—remove all dirt, dust, oil, and debris.

  2. Repair any cracks or holes with filler or a patching compound.

  3. Dry the area completely. Moisture will ruin adhesion.

  4. Roughen the surface using sandpaper or a grinder to help resin bond well.

Step 2: Apply Primer (if needed)

  • If using epoxy resin on porous concrete or timber, apply an epoxy primer to seal the surface.

  • Allow it to cure as per the manufacturer’s instructions.

Step 3: Cut Fiberglass Mat

  • Pre-cut fiberglass matting to the shapes and sizes needed.

  • Overlap sheets by at least 50mm (2 inches) for strength and continuity.

Step 4: Mix Resin

  • Mix resin and hardener according to product directions.

  • Mix only what you can use in 10–15 minutes (resin sets quickly).

  • Always wear protective gloves and a mask—fumes can be strong.

Step 5: Apply First Layer

  1. Apply a layer of resin with a roller or brush.

  2. Lay the fiberglass mat into the wet resin.

  3. Use a fiberglass roller or squeegee to eliminate air bubbles and fully saturate the mat.

  4. Add more resin on top as needed to completely soak the mat.

Step 6: Apply Additional Layers

  • For high-strength waterproofing, repeat the process for 2 layers total.

  • Wait 30–60 minutes between layers (or as specified) but before full curing.

Step 7: Allow to Cure

  • Allow the resin to fully cure—this usually takes 24–48 hours depending on the temperature and resin type.

Step 8: Apply Topcoat (Essential)

  • Apply a UV-stable gelcoat or polyurethane topcoat for protection and aesthetics.

  • This layer also enhances water resistance and extends lifespan.

  • Allow to cure per manufacturer’s instructions.

🧼 Step 9: Clean Up

  • Clean tools immediately with acetone before the resin cures.

  • Dispose of all chemical waste responsibly.

⚠️ Tips & Warnings:

  • Never fiberglass over a wet surface.

  • Use proper ventilation or work outdoors if possible.

  • Always follow manufacturer safety and curing instructions.

  • Wear long sleeves, gloves, and eye protection—fiberglass can irritate skin and eyes.