Protect Wet Areas, Roof Details & Water-Exposed Surfaces

Most waterproofing failures don't start in the middle of an open floor. They show up where surfaces change direction, pipes pass through walls, drains interrupt floors or exterior details give water somewhere to enter. Soudal waterproofing membranes provide liquid-applied solutions for professional wet-area waterproofing, exterior protection & targeted building repairs.

Before choosing a product, establish where the water is coming from, how long the area stays wet, what substrate sits underneath & what will cover the membrane afterwards. A bathroom beneath tiles needs a different system from an exposed roof edge, gutter repair or external penetration.

For complete wet-area projects, browse Waterproofing & Damp Proofing. For roof penetrations, flashings & exposed sealing work, explore Roofing Materials & Sealants.

What Are Soudal Waterproofing Membranes?

Soudal waterproofing membranes are liquid-applied products that cure to form a continuous protective layer across suitable building surfaces.

Rather than treating only an individual joint, a membrane covers the field area while compatible primers, tapes, corner pieces & penetration details help maintain continuity where the construction changes.

The collection centres around two different waterproofing jobs:

► Soudagum LM – a ready-to-use, solvent-free Class III liquid membrane for suitable internal wet areas such as bathrooms, showers & laundries before tiling
► Soudagum Hydro – a one-component waterproof coating for suitable horizontal & vertical surfaces including roof details, gutters, cracks, penetrations & selected exterior repairs

Alongside the membranes, Soudal offers primers & detailing components for specific installation requirements.

The useful distinction isn't simply LM versus Hydro. It's concealed wet-area waterproofing versus exposed protection & repair.

Why Choose Soudal Waterproofing Membranes?

Imagine the waterproofed area before the tiles, fittings or finishes hide it.

Where are the vulnerable points?

Usually they're the places where the waterproof layer has to change direction or work around something: floor-to-wall junctions, internal corners, external corners, drains, pipes, cracks & penetrations.

That's why a waterproofing job should be considered as a system rather than a bucket of membrane.

For suitable Soudagum LM installations, Soudal provides:

► Soudaprim DP for preparing appropriate porous or absorbent mineral substrates
► Soudatape ST for floor-to-wall & wall-to-wall junctions
► Soudatape IC for internal corners
► Soudatape OC for external corners
► Soudatape PD for appropriate pipes & drains

The membrane covers the area. The supporting components help deal with the details that interrupt it.

Common Applications

Bathrooms & Shower Areas

A shower combines frequent water exposure with corners, penetrations, floor junctions & drainage points in a relatively small area.

Soudagum LM is intended for suitable internal wet areas including bathrooms & shower cubicles over substrates such as concrete, cement renders & gypsum boards.

After curing, the waterproofing system is covered by the tiled finish.

Pay particular attention to the transitions around the shower rather than treating the floor or wall area in isolation. Pipework, corners & drains need appropriate detailing so the waterproof layer continues around them.

For associated bathroom installation work, browse Plumbing Fixtures & Accessories.

Laundries & Utility Areas

Laundries face a different exposure pattern.

Water may come from splashing, cleaning or an appliance problem rather than continuous shower use. Soudagum LM is designed for appropriate indoor walls & floors in wet rooms exposed to temporary standing water before the installation of ceramic tiles.

It isn't intended for constant immersion or rising damp.

That distinction matters. If moisture is entering from beneath or through the building structure, coating the visible surface may not address the underlying source.

Concrete, Render & Gypsum Substrates

Before waterproofing, look down.

The condition of the substrate determines what the membrane is being asked to bond to.

Soudaprim DP is a ready-to-use primer for suitable porous or absorbing mineral surfaces including concrete, cement, anhydrite & gypsum boards. It is designed to penetrate the surface, bind residual dust, reduce absorption & strengthen suitable substrates before compatible waterproofing work.

If the project also involves exposed concrete protection outside the wet-area system, browse Concrete Sealers & Coatings.

Corners, Junctions, Pipes & Drains

The easiest part of a waterproofing job is often the broad, uninterrupted surface.

The detailing deserves more attention.

Soudatape ST is used at suitable floor-to-wall & wall-to-wall junctions. Preformed IC & OC pieces deal with internal & external corners while Soudatape PD provides detailing around appropriate pipes & drains.

Count these areas before starting. It is much easier to plan the system while the substrate is exposed than to discover a missing detail halfway through application.

Roof Edges, Flashings & Penetrations

Once waterproofing moves outside, the exposure changes.

Soudagum Hydro is intended for suitable applications including roof & wall cracks, pipe collars, wall breakthroughs, roof edges & chimney flashings.

These areas face rainfall, temperature changes & weather exposure rather than being protected beneath an internal tiled finish.

For complementary exterior sealing applications, browse Roof Sealants & Adhesives.

Gutters & Drainage Repairs

A leaking gutter can make the damaged point obvious—but inspect the surrounding section before assuming the visible leak is the entire problem.

Soudagum Hydro can be used for specified short-term repairs of suitable metal or plastic gutters & drainage.

Check the condition of the surrounding material, joints, falls & drainage path before applying the repair. A coating can't correct a gutter that is structurally failing or holding water because of another defect.

Selected Timber Structures

Soudal also lists Soudagum Hydro for protection & renovation of suitable wooden constructions such as verandas, terraces & garden timber exposed to moisture.

Preparation remains important.

Weathered, loose or contaminated surfaces need appropriate attention before waterproofing. The objective is to create a dependable layer over a suitable substrate rather than simply cover whatever condition already exists.

Product Selection Guide

Which Soudal Waterproofing Product Fits the Job?

Start With Exposure

Ask one question first:

Will the waterproofing sit concealed beneath tiles in an internal wet area or remain part of an exposed protection or repair detail?

That separates most LM & Hydro buying decisions immediately.

Then Check the Substrate

Before coating, inspect for:

► Loose or powdery material
► Dust
► Grease & contamination
► Unsound existing coatings
► Cracks or defects requiring separate attention
► Excessive irregularities
► Highly absorbent areas
► Moisture conditions incompatible with the proposed system

Don't judge readiness solely by whether the surface looks clean from standing height.

Map Every Interruption

Sketching the area before starting can save problems later.

Mark:

► Internal corners
► External corners
► Floor-to-wall junctions
► Wall-to-wall junctions
► Pipe penetrations
► Drains
► Changes in substrate
► Existing cracks

Now the required membrane, primer & detailing components can be planned as a complete job rather than purchased one piece at a time.

Plan What Happens Next

Soudagum LM is intended to be covered with ceramic tiles in appropriate wet-area applications.

Soudal specifies a four-hour recoat time & approximately 12 hours before tiling under the relevant conditions.

Don't use appearance alone to decide when the next stage begins. Product instructions, application thickness & site conditions should guide the handover to tiling.

For general installation, preparation & finishing work around the project, browse Hand Tools.

Expert Tips

Walk the water route. Start where water lands, then consider where it flows, collects or could escape through the construction.

Count details before calculating the field area. Corners, pipes & drains can determine which accessories are needed even when the room itself is small.

Check absorbency before coating. If a mineral surface rapidly pulls moisture from an applied product, determine whether the specified primer is required.

Deal with dust at the substrate—not after the membrane is open. Waterproofing should begin with a surface prepared for adhesion.

Don't bridge an unexplained defect blindly. A recurring crack or moisture problem may need investigation before it disappears beneath a coating.

Watch the wet film as you work. Consistent application matters more than racing to cover square metres.

Keep the system continuous at changes of plane. A beautifully coated wall doesn't compensate for a poorly detailed junction at its base.

Know the difference between rain exposure & immersion. Products designed for wet areas or weather protection aren't automatically suitable for permanently submerged conditions.

Protect finished waterproofing from unnecessary traffic. Once applied, don't turn the area into a walkway for every trade waiting to get through.

Hand over information with the job. If another trade will tile or finish the surface, make sure they know when the system was applied & when the next stage can begin.

For crews working with primers, membranes & other construction chemicals, How to Read a Safety Data Sheet - A Quick Guide for Workshop Operators provides practical guidance on understanding product safety information.

For equipment cleanup after wet trade & construction work, read How To Clean Your Gear Without Ruining It.

For a broader look at preparing equipment & consumables before workloads increase, see Spring Jobsite Prep Getting Your Gear Ready.