HOW-TO · TILE FIXING

How to fix tiles in a swimming pool (that stay put underwater)

A pool is permanent immersion plus movement — the toughest job in tiling. SUMO S04 is the adhesive recommended for swimming pools. Here is how to waterproof, fix and grout so it holds underwater.

LEVEL

Pro

TIME

Multi-day (with cures)

STEPS

WHO THIS IS FOR

Specialist applicators and contractors tiling swimming pools, water tanks and permanently-wet features.

Swimming pools are the most demanding tiling environment there is: permanent water immersion, water pressure, pool chemicals and thermal movement all attack the tile bed at once. A standard cement adhesive and cement grout will not survive it.

The professional build-up is a structural waterproofing layer first, then SUMO S04 — a deformable C2TES1 adhesive recommended for swimming pools — to fix the tiles, and epoxy grout to seal the joints. This guide covers the sequence and the checks that keep a pool watertight.

BEFORE YOU START

What you’ll need

SEALCRETEstructural waterproofingAcrylic Waterproofing Liquid1 kg→S04C2TES1 · recommended for swimming poolsTile & Stone AdhesiveC2TES1 · 20 kg→SUMOXY 2KEN 13888 RGEpoxy Tile Grout · 2-PartEN 13888 - RG · 1 kg→

Notched trowel, epoxy float, mixing gear

Clean water & sponges for epoxy clean-up

THE METHOD

Step by step

Confirm the shell is sound and cured

The concrete shell must be fully cured, structurally sound and free of active leaks. Repair honeycombing and cracks and let repairs cure.

WATCH OUTTiling is not waterproofing. If the shell leaks, fix the structure first — tiles and grout will not hold back water on their own.

Waterproof the shell

Apply a structural cementitious waterproofing coat such as SUMO Sealcrete over the whole shell, with extra care at floor-to-wall junctions, inlets and drains. Build the specified coats and cure.

SEALCRETEPRODUCT USED IN THIS STEPAcrylic Waterproofing Liquid1 kg→

Flood-test before you tile

Fill the waterproofed shell and leave it to confirm the waterproofing holds. Finding a leak now is far cheaper than after the tiles are on.

PRO TIPA flood test after waterproofing and before tiling is the single most valuable check on a pool job.

Fix tiles with SUMO S04

Drain and dry, then fix the tiles with SUMO S04 — a deformable C2TES1 adhesive recommended for swimming pools and wet areas. Comb the bed and back-butter each tile for full, void-free contact.

S04PRODUCT USED IN THIS STEPTile & Stone AdhesiveC2TES1 · 20 kg→

Grout with epoxy grout

Once the adhesive has cured, grout all joints with SUMO Sumoxy 2K epoxy grout, packing every joint solid. Epoxy grout resists pool water and chemicals where cement grout would erode.

SUMOXY 2KPRODUCT USED IN THIS STEPEpoxy Tile Grout · 2-PartEN 13888 - RG · 1 kg→

Cure fully, then fill slowly

Allow the adhesive and grout their full cure time before filling — immersing an uncured system weakens it. Fill the pool gradually so the structure loads evenly.

WATCH OUTFilling before full cure is a common cause of early failure. Respect the cure times on the adhesive and the grout.

AVOID THESE

What to avoid

!Skipping structural waterproofing

Tiles and grout are not a waterproofing layer. The shell must be waterproofed and flood-tested first.

!Using cement adhesive/grout

Permanent immersion and pool chemicals demand epoxy fixing and epoxy grout.

!Leaving voids behind tiles

Water gets behind poorly-bedded tiles and forces them off. Back-butter for full contact.

!Filling before cure

Immersing uncured epoxy weakens the bond. Wait the full cure time, then fill slowly.

QUESTIONS

FAQ

What tile adhesive should I use for a swimming pool?+

SUMO S04 — a deformable C2TES1 adhesive that the brochure recommends for swimming pools and wet areas, over a properly waterproofed and flood-tested shell.

Do I need to waterproof a pool before tiling?+

Yes. Apply a structural waterproofing coat (e.g. SUMO Sealcrete) to the shell and flood-test it before tiling. Tiles and grout do not waterproof a pool on their own.

What grout is used in swimming pools?+

Epoxy grout such as SUMO Sumoxy 2K. It resists constant water and pool chemistry, unlike cement grout which erodes over time.

How long before I can fill a newly tiled pool?+

Wait the full cure time on the adhesive and grout datasheets, then fill gradually. Filling too early weakens the bond.

THE KIT

Products used in this guide

S04SUMO PRODUCTTile & Stone AdhesiveC2TES1 · 20 kg→SEALCRETESUMO PRODUCTAcrylic Waterproofing Liquid1 kg→SUMOXY 2KSUMO PRODUCTEpoxy Tile Grout · 2-PartEN 13888 - RG · 1 kg→SEALCRETE 2K PLUSSUMO PRODUCT2K Flexible Cementitious Coating15 kg→

NOT SURE ON YOUR JOB?

Send us your substrate and tile size — our technical team will confirm the exact method.

Read the datasheet →