Step-by-Step Guide to Repairing Pool Cracks Before Painting

Why Cracks Have to Be Fixed First

Paint does not bridge gaps. That’s the single most important thing to understand before you start — a coating applied over an unrepaired crack will fail there, usually within the first season.

Repair properly and your epoxy or chlorinated rubber finish gets a stable base to bond to.

First: Know When to Stop

Not every crack is a DIY job. Get a professional assessment before you go further if you see:

• Cracks that run the full height of a wall, or continue across the floor
• Any crack that has visibly moved or widened over time
• Large hollow-sounding areas suggesting the render has lost its bond
• A pool that has been losing water

Pool paint will not stop a leak. If your pool is losing water, find and fix the cause before you spend anything on coatings.

Surface cracks, chips, pitting and small hollows are straightforward to repair yourself.

Step 1 — Drain and Inspect

Drain fully, then go over the shell closely. Look for visible cracks, chips and pitting, and tap along the walls — a hollow sound means delamination and needs patching.

Mark everything before you start so nothing gets missed once you’re working.

Step 2 — Clean the Repair Areas

Remove dirt, algae and loose debris from around each crack with a stiff brush and pressure washer. The surface must be dry before any filler goes on.

Step 3 — Widen and Undercut

Using a grinder or chisel, open the crack slightly into a V shape. This removes weak edges and gives the repair compound more surface area to grip.

Goggles, gloves and a respirator — cutting concrete produces silica dust.

Step 4 — Fill

Match the product to the defect:

• Patch & Anchor Polymer Cement — a polymer-modified cement repair mortar for filling cracks, hollows and larger defects in concrete pools. Supplied in 5kg.
• Luxapool® Structural Epoxy Filler — for finer surface imperfections and anywhere you want a smooth epoxy-based finish before painting. Available in 600ml, 2L and 4L.

For both:

• Mix according to the product instructions
• Pack firmly into the crack, pressing deep to eliminate voids
• Smooth flush with the surrounding shell
• Allow to cure completely before moving on

Rushing the cure causes cracking or delamination later, and you won’t know until the paint is already on.

Step 5 — Sand Smooth

Once cured, sand the repair level with the surrounding surface and remove all dust. Any unevenness will telegraph through the finished paint, so take the time.

Step 6 — Prime Where Needed

Bare and uncoated surfaces, including fresh cement repairs, need Luxapool® Epoxy Primer Sealer before the top coats.

Recoating over sound existing epoxy elsewhere in the pool? The repaired patches still need priming even if the rest doesn’t.

Step 7 — Make Sure It’s Dry

Moisture content must be below 5% before painting. No hygrometer? Tape a square of clear plastic to the pool floor overnight — droplets underneath in the morning mean it’s too wet.

Checklist

• ✅ Structural cracks assessed professionally
• ✅ Pool drained and fully inspected
• ✅ Cracks opened, cleaned and dry
• ✅ Filler packed, smoothed and fully cured
• ✅ Repairs sanded flush, dust removed
• ✅ Primed where required
• ✅ Surface below 5% moisture