Ventilated Facades: Benefits and Design

Posted on Feb 21, 2025 in Geology

Advantages of Ventilated Facades

Ventilated constructions offer thermal, aesthetic, and waterproofing benefits to buildings. They prevent overheating in summer, provide water protection, and allow vapor diffusion from the inside to the outside. This ensures optimal moisture regulation and makes it easy to adapt to current and future energy standards. Ventilated facades also offer endless design possibilities.

Air Gap

The air gap should be a minimum of 25mm and as much as necessary, provided there is no wind flowing inside the air gap. The larger the air gap, the more cantilever you will have for fastening the panels to the load-bearing wall. An air inlet less than 20mm does not allow enough air to fulfill its function. With more than 60mm, air can flow in the inlet, and it is not airtight.

Facade Requirements

  • Stability and mechanical strength
  • Fire protection
  • Noise and vibration protection
  • Safety and barrier-free solutions
  • Life and wealth protection
  • Energy saving and heat protection
  • Health and environment protection
  • Sustainable consumption of natural resources

Effects & Requirements According to Impacts

  • Loads from wind, snow, structures: Supporting, Fixing
  • UV radiation: UV Protection
  • Rainfall: Waterproofing, Drain System
  • Internal-external temperature: Thermal Insulation
  • Internal–external vapor pressure: Vapor Resistance
  • Chemical, mechanical etc. interaction: Separation
  • Noise: Sound Insulation
  • Fire: Fire Resistance

Main Groups of Impacts (Effects)

  • Environmental: Weather, climate (rain, snow, wind, temperature, UV radiation), earthquake, noise, fire
  • Functional: Internal air condition, access to the surface, fire, etc.
  • Structural: Loads of the constructions, chemical effects
  • Social: Laws, cultural traditions, standards

Elevation Design Tasks

  • Allocation of façade (load-bearing structure, openings, levels, etc.)
  • Dimensional coordination (dimensions of cladding elements, arrangement of fixing, etc.)
  • Measurements, layers (according to the effects and requirements)
  • Details

Classification of Wall Cladding Structures

  1. By layer arrangement:
    • Single shell
    • Double shell (ventilated)
  2. By weight:
    • Lightweight
    • Heavyweight
  3. By appearance:
    • Homogenous
    • Modular
  4. By construction:
    • Embedded
    • Mounted

Classification by Layers

(1 load-bearing wall, 2 surface coating cladding, 3 thermal insulation, 4 air gap)

  • Single shell:
    • Homogenous (2,1)
    • Thermal insulated (2,3,1)
    • Sandwich (2,3,1)
  • Double shell: Ventilated (2,4,3,1)

Materials of Lightweight Claddings

  • Metal:
    • Steel: 7800 kg/m3, 0.75 mm (6 kg/m2)
    • Aluminum: 3000 kg/m3, 1-3 mm (3-9 kg/m2)
  • Plastic (PVC): 1000 kg/m3, 3 mm (3 kg/m2)
  • Boards:
    • Fiber cement (FC), HPL boards: 1500 kg/m3, 1-2 cm (15-30 kg/m2)
  • Timber: 700 kg/m3, 2-3 cm (15-21 kg/m2)
  • Ceramic: 1500 kg/m3, 1-2 cm (15-30 kg/m2)

Materials of Heavyweight Claddings

  • Stone: 2000 kg/m3, 3 cm (60 kg/m2)
  • Brick: 1500 kg/m3, 10 cm (150 kg/m2)
  • Concrete: 2000 kg/m3, 8 cm (160 kg/m2)
  • (Steel: 7800 kg/m3, 1 cm: 78 kg/m2)

Thermal Insulation Materials

  1. Plastic Foams:
    1. Expanded PS foam: 50/60×100/120 cm, λ: 0.03-0.05 W/mK
    2. Extruded PS foam: 50/60×100/120 cm, 0.02-0.04 W/mK
    3. Polyurethane: 50/60×100/120 cm, 0.03 W/mK
  2. Mineral Wools:
    1. Glass wool: 50/60×100/120 cm, λ: 0.03-0.04 W/mK
    2. Rock wool: 50/60×100/120 cm, 0.03-0.04 W/mK
  3. Wooden Wool

ETICS System

Single shell multilayer system. The cladding has a homogenous connection with the back construction (embedded).

Layers:

  1. Finishing, coloring plaster (0.5mm)
  2. Contact layer: Gluing layer + reinforce mesh
  3. Thermal insulation: PS pearls, Perlite (20cm)
  4. Equalizing plaster
  5. Wall

Fixation of Cladding

  1. Contacted (embedded): Homogenous connection on the base structure (e.g., plastering, brick and stone claddings, up-to-date thermal insulation composite systems (ETICS))
  2. By supporting frame (mounted):
    • Point-wise
    • Linear (profile) (e.g., mounted ceramic cladding, mounted stone cladding, connecting elements of r.c. crust panel)

Plinth Alternatives

Plain, Positive, Negative.

Window Installation

  1. Homogenous: Interior, centered, exterior
  2. Sandwich: Thermal insulation (TI) surrounds the corner, TI overflows the window frame, TI in line with the window frame
  3. Ventilated: Surrounds the corner, TI in line with the window and surrounds cladding, window in line with TI and cladding