Selecting a mesh facade should not be based only on panel pattern, color or mesh opening.

The correct system should be determined by evaluating visual permeability, free air area, mesh geometry, panel size, joint configuration, thermal movement, wind action, panel rigidity, substructure, fixing system, corrosion protection and maintenance access together.

Therefore, the key question should not be:

“Which mesh product looks better?”

but rather:

“Which mesh geometry, panel module and supporting system provide the required architectural and technical performance for this facade?”

For an overview of available systems and applications, see Optimal Mimarlık – Mesh Panel Facade Cladding.

Mesh Facade Selection Should Start with Function, Not Product

The first decision should not be the product code, material or color.

The intended function of the mesh facade should first be defined.

Mesh facades may be used to:

create an architectural secondary skin,
partially conceal technical areas,
maintain natural ventilation on parking facades,
screen air-conditioning and mechanical equipment,
filter direct sunlight,
integrate service areas into the architectural envelope,
create a distinctive metal facade character over large surfaces.

The same mesh product will not provide the same performance in all these applications.

For example, free air area may be the primary criterion in front of mechanical equipment, while visual screening, pattern and architectural continuity may be more important on the main facade of a commercial building.

Which Technical Parameters Should Be Read Together?

For expanded metal and other open metal mesh products, mesh opening alone is not sufficient for selection.

The principal parameters that should be evaluated together include:

long-way mesh dimension,
short-way mesh dimension,
strand width,
strand thickness,
material thickness,
mesh depth,
open area percentage,
mesh orientation,
panel dimensions.

Two products with the same nominal mesh opening may provide very different:

transparency,
light-and-shadow effects,
free air area,
rigidity

because of differences in strand width, material thickness or mesh depth.

Mesh Opening, Open Area and Visual Permeability Are Not the Same

These three terms should be distinguished.

Mesh Opening

The dimensional geometry of an individual opening in the mesh.

Open Area Percentage

The proportion of open voids relative to the total surface area of the panel.

Visual Permeability

How clearly the area behind the mesh can be perceived by the observer.

Visual permeability does not depend only on open area percentage.

It is also affected by:

three-dimensional mesh geometry,
strand depth,
panel orientation,
viewing angle,
distance between the mesh and the rear surface,
background color,
difference between daytime and nighttime lighting.

For this reason, two mesh panels with the same open area percentage may not appear equally transparent on the facade.

Why Should Mesh Orientation Be Defined in the Project?

Expanded metal mesh has a three-dimensional surface geometry.

The same panel may create different:

transparency,
shading,
depth,
light reflection

when installed horizontally, vertically or in the opposite orientation.

Mesh orientation also affects pattern continuity across adjacent panels.

Therefore, panel direction should be clearly indicated in the shop drawings – fabrication and installation drawings and should not be left to site interpretation.

How Should Mesh Panel Size Be Determined?

Panel size should not be based only on architectural grid lines.

As panel dimensions increase, the following may also increase:

total wind force acting on the panel,
surface deformation,
fixing loads,
effect of fabrication tolerances,
transportation and installation difficulty,
thermal movement.

The panel module should therefore be determined by evaluating:

mesh geometry + material + panel size + edge framing + wind action + fixing spacing + joints

as a complete system.

Using very large single panels may reduce the number of visible joints, but it can also make panel flatness and movement more difficult to control.

Why Are Joints Required in Mesh Facades?

Metal facade components expand and contract as their temperature changes.

If this movement is restrained, the resulting stresses may cause:

panel bulging,
surface waviness,
edge distortion,
stress at fixing points.

Large mesh facade surfaces should therefore not be designed as jointless, fully locked metal skins.

Panel joints provide allowance for:

fabrication tolerances,
installation tolerances,
thermal movement.

Thermal Movement Example for a 100 × 300 cm Aluminum Mesh Panel

Assume a mesh panel module of:

1.00 m × 3.00 m

and use an illustrative linear thermal expansion coefficient for aluminum of:

α = 0.024 mm/m·°C

The temperature difference ΔT in this calculation is not simply the difference between outdoor air temperatures.

It is the difference between the minimum and maximum design surface temperatures of the mesh panel material.

The actual panel temperature is affected by:

solar radiation,
facade orientation,
panel color,
surface finish,
ventilation behind the panel,
shading,
wind.

For this example, assume:

ΔT = 45 °C

as an illustrative panel-material temperature difference.

Thermal movement is calculated using:

ΔL = α × L × ΔT

where:

ΔL – Length Change: Change in element length
α – Coefficient of Linear Thermal Expansion: Linear thermal expansion coefficient
L – Length: Original element length
ΔT – Material Temperature Difference: Difference between minimum and maximum design material temperatures

Movement Along the 3.00 m Direction

ΔL = 0.024 × 3 × 45 = 3.24 mm

The theoretical dimensional change along the 3.00 m direction is therefore approximately 3.24 mm.

Movement Along the 1.00 m Direction

ΔL = 0.024 × 1 × 45 = 1.08 mm

The theoretical dimensional change along the 1.00 m direction is approximately 1.08 mm.

This does not mean that the panel joint should automatically be 3.24 mm.

Final joint dimensions should also consider:

fabrication tolerances,
installation tolerances,
fixing configuration,
panel finish and color,
facade orientation,
actual design surface temperatures.

The example simply demonstrates why thermal movement must be considered in mesh facade detailing.

Why Are Fixed and Sliding Connections Used?

It is not always appropriate to lock every fixing point rigidly.

Depending on the system design, the facade may require:

fixed points,
sliding points,
slotted holes,
controlled movement clearances.

The purpose is not to leave the fixing loose.

The purpose is to transfer structural loads while allowing the required thermal movement of the panel or supporting member.

Are Panel Joints and Building Movement Joints the Same?

No.

A panel joint accommodates fabrication, installation and thermal movement of the mesh panels.

A building movement joint or structural expansion joint accommodates movement between parts of the building structure.

The mesh facade substructure should not rigidly bridge a structural movement joint unless a specifically engineered movement detail is provided.

Panel Modulation Should Be Designed Together with Joints

Panel sizes should not be selected first and then separated by arbitrary gaps afterwards.

Facade modulation should be coordinated with:

building grid lines,
floor levels,
windows and doors,
building corners,
structural movement joints,
maintenance access,
manufacturable panel dimensions,
thermal movement.

Correct modulation controls technical movement while also creating a consistent architectural rhythm.

How Is Pattern Continuity Maintained in Expanded Metal Panels?

Random cutting of expanded metal may leave different partial mesh openings along panel edges.

When adjacent panels meet, this can interrupt the visual pattern.

Where possible, panel dimensions should therefore be coordinated with the mesh module so that repeating openings and consistent edge conditions are maintained.

Joint dimensions should also be considered as part of this visual continuity.

How Should Mesh Material Be Selected?

There is no single best material for every mesh facade.

Aluminum Mesh

Aluminum provides:

low weight,
ease of fabrication,
good corrosion resistance,
compatibility with different surface finishes.

Its relatively high thermal movement should be considered in large panels and long supporting members.

Steel Mesh

Steel provides higher rigidity in many configurations.

External applications require an appropriate corrosion-protection system.

Stainless Steel Mesh

Stainless steel is suitable where high corrosion resistance and a natural metallic appearance are required.

The stainless steel grade should be selected according to environmental exposure.

Corten – Weathering Steel

Weathering steel develops a characteristic oxide layer and can provide a distinctive architectural appearance.

Water runoff, staining of adjacent finishes and detail design should be considered at the design stage.

Mesh Panel and Substructure Form One System

The general load path is:

mesh panel → panel fixing → substructure → bracket → anchor → primary structure

The substructure may consist of:

aluminum profiles,
galvanized steel profiles,
coated structural steel,
special extruded systems.

Selection should consider:

panel dimensions,
wind action,
bracket spacing,
primary structure,
corrosion conditions,
thermal movement.

What Should Be Considered When Different Metals Are Used Together?

A mesh facade detail may combine:

aluminum panels,
steel substructure,
stainless steel fasteners,
galvanized anchors.

In the presence of moisture, incompatible metal combinations may create galvanic corrosion.

Where required, the design should incorporate:

separating tapes,
isolation washers,
compatible coatings,
appropriate fixing materials.

This becomes particularly important in coastal and aggressive environments.

How Should Corrosion Protection Be Selected?

Specifying only “anti-rust painted steel” is not sufficient for an exterior facade substructure.

ISO – International Organization for Standardization

The ISO 12944 – Paints and Varnishes – Corrosion Protection of Steel Structures by Protective Paint Systems series is one of the principal international references for corrosion-protection design.

ISO 12944-2 – Classification of Environments

ISO 12944-3 – Design Considerations

ISO 12944-5 – Protective Paint Systems

For suitable fabricated iron and steel components protected by hot-dip galvanizing:

ISO 1461 – Hot Dip Galvanized Coatings on Fabricated Iron and Steel Articles

is one of the relevant technical references.

How Should Wind Action Be Evaluated on Mesh Facades?

Mesh panels remain subject to wind action even though they have an open structure.

Wind behavior depends on:

building height,
facade location,
corner and edge zones,
open area percentage,
mesh geometry,
panel size,
condition of the surface behind the mesh,
distance between mesh and building envelope.

A direct assumption such as:

“The panel has 50% open area, therefore it receives only 50% of the wind load”

should not be made without engineering verification.

Actual aerodynamic behavior should be evaluated according to the project conditions.

What Is EN 1991-1-4?

EN – European Standard

EN 1991-1-4:2026 – Eurocode 1: Actions on Structures – Part 1-4: Wind Actions

provides rules for determining wind actions on buildings, structural elements and exposed components.

The current 2026 edition is part of the second-generation Eurocodes.

EN 1991-1-4 – Wind Actions

For projects in Türkiye, the applicable TS EN – Turkish adoption of the relevant European Standard, National Annex provisions and current local regulations should be checked.

Why Should Facade Corner Zones Be Checked Separately?

Wind suction at building corners and edge zones may be higher than in the central areas of the facade.

For this reason, using exactly the same:

substructure profile,
fixing spacing,
anchor arrangement

throughout the entire facade is not automatically correct.

The supporting system should be checked according to the wind zones defined by the structural design.

How Should Free Air Area Be Determined?

For mesh panels installed in front of:

open parking areas,
mechanical spaces,
air-conditioning outdoor units,
ventilation equipment,

open area should not be selected only according to appearance.

Required airflow should be evaluated together with:

equipment airflow demand,
intake and discharge direction,
distance between equipment and mesh,
mesh open area,
surrounding obstructions.

The mesh should conceal technical equipment without restricting the airflow required for operation.

Can Mesh Facades Provide Solar Control?

Yes.

A mesh panel positioned in front of the main facade acts as a secondary layer that filters direct solar radiation.

Its effectiveness depends on:

mesh geometry,
mesh depth,
orientation,
facade direction,
distance between mesh and glazing.

For this reason, solar-control performance cannot be defined only by the open area percentage.

Why Does a Mesh Facade Look Different During the Day and at Night?

During daylight, the exterior may be much brighter than the space behind the mesh, causing the panel to appear more opaque.

At night, when the rear area is illuminated, the same mesh can appear considerably more transparent.

This is particularly important where the facade is intended to conceal:

mechanical equipment,
pipes,
cable trays,
service areas.

What Is a Mock-Up?

A mock-up – full-scale application sample allows the selected material and details to be evaluated before final fabrication.

For mesh facades, a mock-up can be used to assess:

color,
visual permeability,
mesh orientation,
joint appearance,
fixing visibility,
visibility of the substructure,
day-and-night appearance.

Small catalogue samples cannot reproduce all of these conditions.

How Should Fire Performance Be Considered?

A metal mesh panel alone does not define the fire performance of the complete facade assembly.

The evaluation may also include:

surface coating,
substructure,
backing materials,
insulation,
cavity configuration.

EN 13501-1 – Fire Classification of Construction Products and Building Elements

is one of the principal European references for reaction-to-fire classification.

EN 13501 – Fire Classification

For projects in Türkiye, the current requirements of the Regulation on Fire Protection of Buildings should also be considered.

How Should You Choose Between Mesh Facade and Perforated Panel?

The two systems may serve similar architectural purposes, but their surface structures are different.

Mesh Facade

The main parameters are:

three-dimensional mesh geometry,
strand structure,
mesh orientation,
viewing-angle-dependent permeability.

Perforated Panel Facade

The main parameters are:

hole size,
hole geometry,
perforation percentage,
sheet thickness,
cassette or panel rigidity.

Selection should therefore be based not only on appearance but also on:

ventilation,
visual screening,
solar control,
rigidity,
architectural intent.

What Should a Mesh Facade Technical Specification Include?

A specification stating only:

“Aluminum mesh facade shall be installed.”

is not sufficient.

At minimum, the following should be defined:

mesh type,
material and alloy/grade,
material thickness,
strand width and thickness,
long-way and short-way mesh dimensions,
mesh depth,
open area percentage,
mesh orientation,
panel dimensions,
panel-joint principle,
movement principle,
edge framing,
surface finish,
color,
substructure,
fixing system,
fixed/sliding connection principle,
anchors,
corrosion protection,
wind-design criteria,
maintenance and removability requirements.

This allows quotations and products to be compared on the same technical basis.

What Should Be Shown in Shop Drawings?

A mesh facade shop drawing – fabrication and installation drawing set should show:

panel numbers,
panel dimensions,
mesh orientation,
panel joints,
structural movement joints,
substructure,
brackets,
anchors,
fixed and sliding points,
slotted holes where required,
corner details,
window and door returns,
removable maintenance panels.

Production should be based on approved shop drawings rather than architectural elevations alone.

Recommended Mesh Facade Selection Sequence

A practical selection process is:

Define the intended facade function.
Define required visual screening.
Determine ventilation requirements.
Select mesh geometry.
Determine open area percentage.
Define mesh orientation.
Select material.
Establish panel modulation.
Define fabrication and installation tolerances.
Evaluate thermal movement.
Define panel joints.
Resolve fixed and sliding connections.
Determine wind actions.
Check panel rigidity.
Design the substructure.
Verify anchors and primary-structure connections.
Resolve corrosion protection and dissimilar-metal interfaces.
Check fire and ventilation requirements.
Design maintenance access.
Approve the mock-up where required.
Prepare shop drawings.
Fabricate and install according to the approved design.

Optimal Mimarlık Mesh Facade Systems

Mesh facade performance is not determined by the metal panel alone.

A reliable system is created by resolving:

mesh geometry + permeability + mesh orientation + panel size + joints + thermal movement + wind design + substructure + fixings + anchors + corrosion protection + installation

as one coordinated facade system.

For product information:

Optimal Mimarlık – Mesh Panel Facade Cladding

For facade design, fabrication and installation services:

Optimal Mimarlık – Curtain Wall Services

For common design and installation problems:

Common Mistakes in Mesh Facades and Correct Application Criteria

Quick Answers

Are joints required in mesh facades?

Yes. Joints accommodate fabrication and installation tolerances as well as expansion and contraction caused by changes in material temperature.

How much can a 100 × 300 cm aluminum mesh panel move?

Using an illustrative expansion coefficient of 0.024 mm/m·°C and a 45 °C panel-material temperature difference, the theoretical dimensional change is approximately 3.24 mm along the 3.00 m direction and 1.08 mm along the 1.00 m direction.

Is the 45 °C value the outdoor air-temperature difference?

No. It represents the assumed difference between the minimum and maximum design surface temperatures of the mesh panel material in the example.

Does this mean the panel joint should be 3.24 mm?

No. The value represents only theoretical thermal movement. Fabrication tolerances, installation tolerances, connection design and actual project temperatures must also be considered.

Why can mesh panels become wavy?

Waviness may result from insufficient rigidity, oversized panels, wind action, or restrained thermal movement caused by inadequate joints or incorrect fixings.

Can all mesh-panel fixings be rigid?

Not in every system. Long elements or systems with significant thermal movement may require a combination of fixed and sliding connections.

Is a panel joint the same as a structural expansion joint?

No. Panel joints accommodate panel-related movements, while structural movement joints accommodate movement of the building structure.

Do mesh facades require wind-load calculations?

Yes. An open mesh structure is still exposed to wind action. Panels, fixings, substructure and anchors should be designed accordingly.

Why is a mock-up useful for mesh facades?

A full-scale mock-up allows permeability, orientation, color, joints, fixing appearance and day/night visibility to be evaluated before fabrication.

Technical Editor and Content Review:
Mehmet Beşe Polatkan, Architect (YTU)

Copyright and Use

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It may not be copied, reproduced, or republished without permission. For quotations made within the scope of Article 35 of Law No. 5846, the source must be cited as Optimal Mimarlık – www.optimalmimarlik.com.