Express Course

How to make a private bathroom waterproof

Learn how to install bonded waterproof insulation in private showers & bathrooms.

Crucial to know
Tools needed
Step 1
Step 2
Step 3
Step 4
Tips & Tricks
products used
Recommendation

Crucial to know

Application in 2 coats

CL 51 dry thickness layer 0.5 mm

CL 50 dry thickness layer 2 mm

Tools needed

A brush

A trowel

A drill with a mixer paddle

Sealing tapes

Step 1

Collars around water pipe inlets.

Ceresit, CM 77, difficult substrates, noched trowel, Alu surface, chipboard surface, glass surface, tile adhesives, epoxi tile adhesives

Collars around a shower drainage.

Sealing tape in the corner.

Sealing collar around a bathtub opening.

Basic info about products

Ceresit CL 50 is two-component, cement + polymer dispersion sealing film (more here).
Ceresit CL 51 is one-component dispersion based waterproofing film (more here).
Ceresit CL 72 is epoxy resin product with high crack-bridging ability and resistance to thermal and mechanical stresses.

Liquid waterproofing products

For bonded waterproofing system you can choose a polymer-mortar sealing film or the epoxy sealing. Both can be used with the sealing tapes and collars. Liquid-applied products for waterproofing purposes and tested in compliance with EN 14891 feature a crack-bridging ability. They produce a stress-compensating bond between screed and tile adhesive.

Ceresit CL 50 is two-component, cement + polymer dispersion sealing film (more here).
Ceresit CL 51 is one-component dispersion based waterproofing film (more here).
Ceresit CL 72 is epoxy resin product with high crack-bridging ability and resistance to thermal and mechanical stresses.

Please not that all waterproofing products above should be applied in two layers (coats). Necessary dry layer thickness for Ceresit CL 50 is 2 mm and for Ceresit CL 51 only 0,5 mm (wet film 1 mm). First layer can be applied with a brush and the second one with a brush or a trowel.

SEALING TAPES FOR JOINTS, CORNERS, PIPE INLETS AND DRAIN OPENINGS

It is recommended to embed waterproofing tapes and collars in all corners, around joints and openings (shower and bathtub drains). For this purpose use Ceresit CL 82 Ultratape, Ceresit CL 152 Sealing Tape and Ceresit CL 83 Sealing Collar.

The sealing tapes and collars should be embedded in the first layer of liquid waterproofing and covered with the second one.

Step 2

Substrate testing & preparation

testing and preparation of the substrate

For these subjects, please find the related articles: Substrate testing, How to prepare floor for tiling, How to prepare wall for tiling, How to apply self-levelling compound, and for priming How to choose the right primer.