Interior and finishes · Wall Finishes & Linings
Tadelakt Soap Cured Lime Wall Finish
Describes tadelakt as a craft lime finish and separates it from the wider polished plaster family, without presenting it as a waterproofing measure.
Educational reference entry. Suitability depends on the complete assembly, substrate, exposure, installation method, manufacturer documentation, local requirements and qualified professional review.
Overview
What tadelakt is
Tadelakt is a lime finish that originated in Morocco, where it has long been used on the walls of bathing rooms, cisterns and interior surfaces. It is applied by hand, compressed and burnished while it sets, and then treated with a soap. The density comes from that hand compression and burnishing, while the soap reacts with free lime at the surface to give the characteristic sheen and surface character.
The result is unlike a boarded or tiled surface because it has no joints. It can be carried around curves, into reveals and over formed shapes as one continuous skin, and its surface is never perfectly flat: the burnishing leaves subtle variation in tone and reflection that is the signature of the material and the hand that applied it.
It sits close to the polished plaster entry elsewhere in this library, and the distinction is worth stating. Tadelakt is specifically a lime finish finished with soap, worked by compression rather than built for pattern, and it belongs to a craft tradition with a limited number of experienced practitioners. Choosing it is as much a decision about who will apply it as about the material itself.
Terminology
Common names and aliases
These names describe the same thing. The library keeps one entry per material so that an acronym, a trade name or a regional spelling never becomes a second, thinner page.
- tadelakt finish
- moroccan lime finish
- soap treated lime finish
Applications
Common applications
Where this material is typically encountered. A typical application is not a statement that it suits your project.
- Bathroom and shower-room walls, as part of a wider strategy determined by whoever is designing the room.
- Seamless basin surrounds, alcoves and formed shapes where a continuous surface without joints is the intention.
- Feature walls and niches in living spaces where the hand-worked variation of the finish is the point of it.
- Restoration and new work in buildings where a traditional lime finish suits the character of the interior.
Consideration
Where it is commonly considered
- Where an owner specifically wants a hand-worked, jointless lime surface and values its variation over uniformity.
- Where an experienced practitioner is available, since the outcome depends heavily on the skill applying it.
- Where the background has been assessed as suitable for a lime finish by the person who will be applying it.
- Where curved or formed surfaces make a jointed material awkward and a continuous skin is the design intention.
Professional review
Where additional professional review is especially important
These are the situations where the answer depends on the specific building, and where a qualified professional should be involved before anything is decided.
- Anywhere the finish is being relied on in place of a waterproofing strategy, which is a matter for a qualified professional.
- In shower enclosures and other heavily wetted areas, where the whole assembly and its drainage govern what is possible.
- On backgrounds that move, flex or have unresolved cracking, since a continuous finish shows movement plainly.
- Where no experienced practitioner is available and the work would be attempted from written instructions alone.
- Where a uniform, repeatable surface is expected, since hand-applied variation is inherent to the finish.
- On walls with suspected damp, until the cause has been investigated by someone qualified to do so.
Properties
Key properties to discuss
Qualitative topics worth raising. Measured values, classes and grades come from the manufacturer's technical documentation for the specific product, not from a reference page.
- Appearance
- Tone and reflection vary across a burnished surface and shift with the light. Two walls in the same room, finished on different days or by different hands, will not read identically, and that is inherent to the material.
- Moisture behaviour
- Tadelakt is dense and jointless, but density is not a waterproofing system. What a wetted room requires is determined by its complete waterproofing and drainage design, and that is a professional matter rather than a finish choice.
- Substrate dependency
- The finish follows and depends on what is behind it. Background type, stability and suction all affect the outcome, and the practitioner will want to assess them before agreeing to work on a particular wall.
- Installation dependency
- Application, compression and soap treatment are craft operations carried out in a particular order by an experienced hand. This entry deliberately gives no method, because a written sequence is no substitute for that experience.
- Maintenance
- Surfaces are looked after in ways specific to lime and soap, and ordinary household cleaners are not automatically appropriate. Care guidance should come from the practitioner who applied the finish.
- Repairability
- Damage is repaired by hand into a continuous surface, and matching the tone of an aged finish is difficult. A repair is normally visible for a period before it settles towards the surrounding colour.
- Surface wear
- The finish is worked to be dense, but it remains a lime surface and can be marked by impact and by contact with certain substances. What matters in practice is the specific room and how it is used.
Exposure
Exposure and environmental conditions
- How wet does this surface actually get, and what else in the room is managing that water?
- Where does water drain, and how quickly does the room dry after use on an ordinary day?
- Is there ventilation appropriate to the way this room will be used, and who has assessed it?
- Does the background take any moisture from elsewhere, and has that been investigated by a qualified person?
- What temperature and humidity conditions will the finish experience while it is being applied and afterwards?
- Are there fittings, seals or junctions in this room that will demand attention where they meet a continuous surface?
Assembly
Substrate and system dependencies
What this material sits on, is fixed to or depends on. This is usually where performance is won or lost.
- Background type and stability govern what the practitioner can achieve and whether they will take on the wall at all.
- Junctions with baths, trays, basins and fittings need designing and are a common point of difficulty for jointless finishes.
- Any waterproofing measures for the room belong to the room's design and are decided by a qualified professional.
- Movement joints and changes of background material behind a continuous finish will tend to show through it eventually.
- Services, fixings and pipe penetrations should be resolved before the finish is applied rather than cut in afterwards.
Appearance
Appearance and finish considerations
- Colour comes from pigments and from the lime itself, and it develops as the finish carbonates rather than being fixed at once.
- Sample panels are the only meaningful way to judge the finish, and they should be made by the person who will do the work.
- The surface is deliberately undulating, and anyone expecting a flat mechanical evenness will be disappointed by it.
- Sheen varies with the degree of burnishing and reads very differently under direct light and under diffuse light.
- Corners, arrises and returns are where the character of a hand-applied finish is most apparent.
- The finish looks different when wet, which matters in a bathroom where surfaces are regularly seen in both states.
Durability
Durability questions
Questions to raise rather than a service life to expect. No material has a universal lifespan — it depends on the assembly, the exposure and the upkeep.
- How is this surface expected to age in this specific room, given how the room is actually used?
- What marks it, and what does the practitioner say should be kept away from the finish?
- How does the finish behave where fittings are attached to it or where it meets another material?
- What happens at the base of a wall where water collects, and how is that junction being handled?
- Who will be available to attend to the finish in future, and is that practitioner likely to still be working locally?
Upkeep
Maintenance and repair considerations
- What routine care does the practitioner recommend for this finish in this room?
- Which cleaning products must be avoided, and what would they do to a lime surface?
- How often does the surface need attention, and what does that attention actually involve?
- Can a damaged area be repaired locally, and how well will that repair blend once it has settled?
- Who would carry out a repair, and is that arrangement being recorded at handover?
- What should be done if the surface is marked during the remaining site works?
Installation
Installation dependencies
What the installation depends on — not how to do it. Method belongs to the manufacturer's instructions and the trades carrying out the work.
- The finish depends on the practitioner more than on any product, so their experience and references matter most.
- Programme matters, because a lime finish sets and develops on its own timescale and cannot be hurried by a deadline.
- Site conditions during the work are controlled by whoever is applying the finish and affect the outcome directly.
- Coordination with the fitting of sanitaryware and fittings has to be agreed, since the sequence affects the junctions.
- Protection of the finished surface during the rest of the works needs to be assigned to somebody explicitly.
Documentation
Documentation to request
Ask for these in writing, for the specific product being proposed, and keep them with the project record.
- A written description of the materials the practitioner proposes to use, in their own words.
- Photographs of their completed work, ideally including surfaces that have been in use for a period.
- Sample panels retained on site, labelled and kept for reference against the finished walls.
- Written aftercare guidance covering cleaning, what to avoid and how to report damage.
- A record of who applied the finish and how to contact them, kept with the handover information.
- Confirmation in writing of what the finish is and is not being relied upon to do within the room.
Conversations
Questions for qualified professionals
Bring these to the relevant qualified professional, manufacturer or authority. Requirements vary by project and location.
- How is this room being waterproofed, and what part is the finish expected to play in that?
- Who is applying this finish, and can I see and touch surfaces they have completed?
- Will you make a sample panel for this room, and can I keep it?
- How will the finish meet the bath, the tray, the basin and the fittings?
- What background will this go onto, and have you assessed it yourself?
- How should I clean and care for this surface once we are living with it?
- What will the finish look like after a year of use in a room like this?
- If it is damaged, who repairs it and how visible will that repair be?
- How does this differ from a polished plaster finish for this particular room?
- What are you not willing to guarantee about this surface, and why?
Blind spots
Commonly overlooked points
- The choice of practitioner determines the outcome more completely than with almost any other wall finish.
- Junctions with fittings, not the flat wall areas, are where a jointless finish most often becomes complicated.
- A finish that is dense and seamless is still not a waterproofing strategy for the room it sits in.
- The finish continues to change in tone for a period after it is applied, which unsettles owners who expect it fixed.
- Protection during the remainder of the works is regularly forgotten and is expensive to put right afterwards.
- Aftercare guidance is often given verbally and then lost, so getting it in writing at handover is worth insisting on.
What this page does not do
- No claim about resistance to water in isolation is made here; wet-area behaviour is a property of the complete designed assembly.
- No application method, soap treatment, burnishing sequence or curing schedule is given here, and none should be inferred.
- Tadelakt is not presented as a substitute for a waterproofing strategy, which is a matter for a qualified professional.
- Outcomes vary with the practitioner, the background and the room, so no general statement about results can be made.
- Build Design Hub publishes this entry as reference material and does not test, approve or recommend any finish or practitioner.
Related entries
Related materials
Materials from the same family, an adjacent role in the assembly, or a shared application.
Inspiration
Related Ideas Library pages
Design directions where this material commonly appears.
Preparation
Related planning checklists
Owner-side preparation before the conversation where this material comes up.
Go deeper
Related Build Design Hub guides
Planning guidance and neutral comparisons behind the decisions on this page.
Wall Finishes & Linings
Reference entries for internal wall and ceiling materials — plasterboard, gypsum, lime and clay plasters, polished plaster, paints, primers, wallpaper, panelling and acoustic linings.
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