Building envelope · Facades & Cladding
Adhered Tile and Stone Facade System
This entry follows the dependency chain in a bonded facade — background, preparation, bed, unit, joint — and identifies loss of adhesion at height as the condition the whole assembly is organised around.
Educational reference entry. How this system behaves depends on climate, jurisdiction, loading, substrate, the adjacent systems it meets, how the building is used, the manufacturer's instructions and qualified professional design.
Overview
What adhered facade is
An adhered facade is held on by bond. The units are bedded onto the wall in a continuous adhesive layer, and that layer is a structural connection distributed over the whole back of every unit rather than a set of discrete fixings. Nothing hangs, nothing is hooked and nothing is bracketed; the facade is, in effect, part of the wall.
There is no cavity, and that single absence explains most of the assembly's behaviour. There is no drained space to receive water that gets past the units, no ventilated gap to dry the back of them, and no separation between what the background does and what the facade does. Everything the background does is transmitted into the facade rather than interrupted before it reaches it.
Movement therefore has to be provided for rather than absorbed. Background shrinkage, thermal movement in a sunlit facade and structural movement in the wall behind all pass straight into the bond, so the facade carries a grid of movement joints that has to continue through the units, through the bed and through any levelling layer to reach the background. A movement joint grouted solid is a line along which units debond.
The failure mode that defines the system is loss of adhesion at height. A tile or stone unit that has lost its bond is a piece of hard material held only by its grout on a vertical surface above ground, which is why the preparation of the background, the coverage of the bed behind each unit, the provision of mechanical restraint where the bond alone is not relied on, and the ability to inspect the facade later all belong to the same discussion.
Terminology
Common names and aliases
These names describe the same assembly. The encyclopedia keeps one entry per system so that a trade term or a regional name never becomes a second, thinner page.
- direct-bonded stone facade
- adhered stone cladding
- external wall tiling
- bonded tile facade
- adhered masonry veneer (North America)
Purpose
What this system is intended to do
The job the assembly exists to perform, conceptually. An intention is not a guarantee that any particular build achieves it.
- Present a facade of hard units whose appearance is that of masonry or stone without a self-supporting leaf or a supporting framework.
- Transfer the weight of every unit into the background through a continuous bonded connection rather than through discrete fixings.
- Keep the assembly thin, since nothing is standing off the wall and there is no cavity to occupy.
- Carry a grid of movement joints through every bonded layer to the background, so that movement in the wall does not appear as debonding in the facade.
- Manage water at the surface and at the terminations, since there is no drained space behind the units to manage it in.
- Keep units restrained where the bond alone is not being relied on to hold them.
Composition
The roles this system is made of
What each part does in the assembly and what it depends on — never a product, a thickness, a fixing or a determination that anything is adequate for the role.
Order is meaningful in this system. The roles below sit in sequence, and moving one relative to another changes what the assembly does. The sequence is conceptual only: it states no thickness, no dimension, no fixing and no order of work on site.
- Layer 1 of 8. Order is meaningful.Primary supportBacking wall
The wall the facade is bonded to, which carries it through the bond rather than through brackets. Its own movement becomes the facade's movement, its flatness sets how much levelling is needed, and its age and condition decide whether it is still shrinking when the units go on.
- Layer 2 of 8. Order is meaningful.SubstratePrepared and levelled background
The surface the units are actually bedded onto: the backing wall itself where it is sound and flat enough, or a rendered levelling coat or board over it. Whatever it is, the bond is only as good as this layer's own hold on what is behind it, so it becomes a link in the chain rather than a preparation step.
- Layer 3 of 8. Order is meaningful.Control layerDecoupling or waterproofing layer
A layer placed between background and bed where the background's movement is to be partly separated from the facade, or where water reaching the background has to be dealt with. It changes the chain rather than adding to it: what is bonded to what, and where the weakest link now sits, both change when it is introduced.
- Layer 4 of 8. Order is meaningful.AttachmentAdhesive bed and mechanical restraint
The continuous adhesive layer that is the facade's connection to the wall, together with any mechanical fixings retaining units where the bond alone is not relied on. How completely the bed is in contact with the back of each unit is the property that matters, and it is invisible the moment the unit is placed.
- Layer 5 of 8. Order is meaningful.Finish surfaceTile or stone units
The visible facing. Its size, weight, absorbency and back profile all affect how it bonds and how it behaves in sun and frost, and stone in particular brings its own variation in a way that manufactured tile does not.
- Layer 6 of 8. Order is meaningful.Jointing and sealingGrouted joints between units
The filled joints across the field of the facade, which close the surface and determine how much water reaches the bed. They are not movement joints and are not intended to move, which is why the difference between a grouted joint and a movement joint has to be visible on the drawings and on the wall.
- Layer 7 of 8. Order is meaningful.Jointing and sealingMovement joint grid
The deliberate breaks running through the units, the bed and any levelling layer to the background, at the perimeter of the facade, at internal corners, at structural movement lines and at intervals across the field. They are what give background movement somewhere to go instead of into the bond.
- Layer 8 of 8. Order is meaningful.Edge and terminationCorners, reveals, base and drip
Every place the bonded field stops: external and internal corners, window and door reveals, the top of the facade and the bottom edge. The base termination and its drip decide whether water running down the face leaves the wall or is delivered behind the lowest units, where freezing does the rest.
Interaction
How the parts work together
The reason this is a system rather than a list of parts: what depends on what, and what stops working when one part is changed.
The assembly is a chain of bonds and it is only as strong as its weakest link. Unit to bed, bed to levelling layer, levelling layer to background: a failure at any one of them presents identically from the outside, as units coming off. This is why the preparation of the background is not preliminary work but a component in its own right.
Movement in the background goes straight into the bond unless the movement joint grid reaches the background. Grout a movement joint solid and the units debond in a line along it; stop the joint at the back of the units and the layer beneath is still continuous across the movement. The joint has to pass through every bonded layer to be a joint at all.
Timing is part of the assembly. Bed onto a background that is still shrinking and the bond is being asked to hold across movement that has not finished, so the connection can break before it has ever been loaded by anything other than the wall behind it.
With no cavity, water has only two routes: through the surface into the bed, or down the face to the bottom edge. That makes the grouting and the base termination the whole of the water strategy, and it makes freezing conditions a question about what is behind the units rather than about the units themselves.
Materials
Material families commonly met in each role
Commonly encountered, not recommended. Whether a material suits a given project depends on the whole assembly, the exposure, the manufacturer's documentation and qualified professional review.
Primary support
These backgrounds are commonly encountered behind bonded facades. Each has its own suction, its own movement behaviour and its own surface condition, and what any of them requires before bedding is a matter for the designer and the product documentation.
Substrate
Levelling and separating layers from these families are commonly met between the background and the bed. Introducing one adds a link to the chain of bonds, which is a design decision rather than a preparation detail.
Attachment
Bedding materials and, where mechanical restraint is provided, corrosion-resistant fixing families are commonly encountered here. What may be bonded to what, and with what, is read from the manufacturer's documentation and settled by the facade designer.
Finish surface
These unit families are commonly met as the facing. They differ in weight, absorbency, dimensional variation and how they behave in frost, and those differences bear directly on how each is bedded.
Jointing and sealing
Movement joints through a bonded facade are commonly closed with sealants from these families over a backing. The grouted joints across the field are a different material and a different function, and the two are commonly confused on site.
Edge and termination
Trims, copings, sills and drip pieces at the edges of a bonded facade are commonly formed from these families. What each has to do at a particular termination is a detailing matter for the designer.
Boundary
Where this system ends and meets another
The edge of this system. Everything above is inside it; each junction below is a condition at its boundary, where an adjacent system or an adjacent building condition takes over. Junctions are where most assemblies actually fail, so they are set out explicitly rather than left inside the prose. What resolves one is a detail designed for the specific building — not a rule of thumb.
Bonding onto the outer leaf of a cavity wall
Bonding a facade onto the outer leaf loads that leaf with the weight of the units and covers the surface it was shedding water from. The leaf's own movement joints then have to be carried through the bonded facade, and the cavity's drainage arrangements have to be read again with the outer face closed.
Read about Twin-Leaf Cavity Wall →Bonding onto a wall that works by absorbing water
A solid wall takes moisture in and gives it back by evaporation from its surface. Covering that surface with bonded units changes where the wall can dry from, which is a question about the wall rather than about the facade and has to be resolved before the units go on.
Read about Solid Wall →Reveals, sills and heads at openings
An opening turns the bonded field into a perimeter, and the facade has to stop, turn into the reveal and be terminated against the frame. These are also the points at which water running down the face is concentrated, so the sill and the junction beneath it carry more than their share of the facade's water.
Read about Window Opening Interface →The base of the facade at the ground
The bottom edge of a bonded facade is where splash, run-off and any moisture rising in the wall all arrive, and where the units are closest to freezing wet. Where the facade stops relative to the damp-proof layers, and how the bottom edge sheds water clear, is settled here rather than at the top.
Read about Damp-Proof Continuity →Trays and drainage openings behind a bonded face
Where the wall behind carries trays that discharge to its outer face, a bonded facade covers those outlets. Whether and how the discharge is brought through the facade has to be resolved before the units go on, since it cannot be added afterwards without breaking the bonded field.
Read about Cavity Trays →Render used as the background rather than as the finish
Where the units are bedded onto a rendered levelling coat, the render's own rules apply beneath the facade: its key to the background, the grading of its coats and its own movement joints. The render then stops being a finish and becomes a structural link in the chain of bonds.
Read about Direct Render →Movement joints continued from the structure behind
A movement joint in the structure or in the background wall has to appear as a movement joint in the facade, on the same line and through every bonded layer. A joint that is offset, or that stops at the back of the units, is taking movement in the material between the two lines.
Considerations
Topics worth discussing
Which topics genuinely apply to this system and what to raise about them. Measured values, classes and ratings come from a qualified professional's design for the specific building, not from a reference page.
- Durability
- The condition that defines this system is loss of adhesion at height, where a hard unit on a vertical surface above ground is retained only by its grout. Whether mechanical restraint is provided, and to which units, is a design determination and is not inferred from the size or the material of the facing.
- Movement
- With no cavity, background movement is transmitted rather than interrupted, so the movement joint grid is the assembly's only provision for it. Where those joints go, and how far through the build-up each one reaches, is established by the facade designer.
- Moisture
- Water that passes the grouted surface arrives in the bed with nowhere to drain to, and the bottom edge is the only place the face itself discharges. Freezing conditions act on whatever moisture is held behind the units, which is why base terminations and drips carry more weight in this system than in a drained one.
- Buildability
- Coverage of the adhesive behind each unit is the property everything depends on, and it becomes invisible the moment the unit is placed. The conditions the facade is built in, and the state of the background when bedding starts, therefore affect what can never be seen again.
- Maintenance and access
- A bonded facade cannot be taken off and put back. Inspection, the ability to detect units that have lost bond before they come off, and access to a wall above ground for any of that are ongoing questions that belong in the design discussion rather than in the first maintenance year.
- Interfaces
- Every edge of the bonded field is a termination, and the base, the corners and the reveals are where the system stops behaving like a surface. Most of what the facade needs from adjacent construction is asked for at those lines.
Design
Questions the design has to answer
The decisions this assembly turns on. They are questions rather than answers, because the answer depends on the building.
- What is the facade actually bonded to, and what is that layer in turn bonded to?
- Has the background finished moving, and how is that being established before bedding starts?
- Where does the movement joint grid run, and does every joint reach the background through each bonded layer?
- Is mechanical restraint being provided in addition to the bond, and to which units?
- How does the bottom edge of the facade shed water clear of the wall?
- What happens to any drainage from the wall behind that used to discharge at the face the facade now covers?
- How will units that have lost their bond be identified before they come off?
- What access is available to this facade once the building is in use?
Boundaries
Commonly misunderstood points
Distinctions that are easy to blur, and the places where a familiar term means something narrower than it sounds.
- This is not a rainscreen with a thin screen. There is no drained space, no ventilated cavity and no separate control layer behind the units, so nothing that reaches the bed has anywhere to go.
- It is not a brick slip facade either. A brick slip system's defining element is a carrier rail, board or panel that turns scattered facings into one supported plane, commonly with a drained space where the carrier stands clear; here the units are bonded to the wall itself and there is neither.
- It is not render with units in it. A render build-up is monolithic coats with no units and no joints; this assembly is discrete units, a bed and a joint pattern, and the joints are where its behaviour lives.
- Grout is not what holds the facade on, and a facade whose grout is sound tells you nothing about the bond behind it.
- A movement joint filled with grout is not a movement joint. It is a line of units waiting to debond.
Conversations
Questions for qualified professionals
Bring these to the relevant qualified professional, manufacturer or authority. Requirements vary by project and location.
- What is the full chain of bonds here, from unit to background, and which link is weakest?
- What background preparation has been specified, and how will it be verified before bedding starts?
- Where is the movement joint grid, and how far through the build-up does each joint reach?
- Is mechanical restraint being provided, and on what basis has that decision been made for this facade?
- What coverage of adhesive behind each unit is intended, and how is it being checked during the works?
- How does the base of the facade terminate, and how does water leave the bottom edge?
- What inspection regime is proposed for this facade once the building is occupied?
What this page does not do
- This entry describes how the assembly is organised. It is not a specification, a facade build-up for a particular building, or a substitute for design by a qualified professional.
- Whether a bonded facade is appropriate at a given height, on a given background and in a given exposure is a design determination, and no part of that judgement can be taken from a general reference.
- The retention of hard units on a wall above ground is a safety-related matter that belongs with qualified designers and with the jurisdiction, and must be verified against local requirements.
- An existing adhered facade showing hollow-sounding, cracked or displaced units should be assessed by a qualified professional rather than repaired locally.
Related systems
How this system relates to others
Every link states what the relationship actually is, rather than leaving a bare list of related pages to be read as a suggestion.
Alternatives
Different systems answering the same need. Listing them together is not a comparison and does not suggest one is better — which, if either, suits a project is a design decision.
Applications
Building contexts this system is used in
The functional parts of a building this assembly is commonly met in. This is membership, not a ranking and not a recommendation: several systems answer any one context, and which of them suits a project is a design decision. A context appearing here does not mean the system is suitable, permitted or adequate for it.
- Facade · Envelope
Go deeper
Related Build Design Hub guides
Planning guidance behind the decisions this assembly involves.
Preparation
Related planning checklists
Owner-side preparation before the conversation where this system comes up.
Facade and Cladding Systems
Outer skins carried on a wall that is already complete behind them, where the support, the joint and the cavity carry the durable knowledge rather than the finish.
Browse all facades & cladding entries →