PROWALL for timber frame
Seamless Rendered Rainscreen Cladding System

This cavity-based rendered rainscreen is a hassle-free option for timber frame buildings, providing a solution to movement and fire safety. It provides a rendered surface coupled with a free-draining cavity, making breathable buildings with a tough, attractive and low maintenance façade.

With integrated fire safety, premium render carrier boards and a high-quality render finish, ProWall is a complete system and top choice for many architects and developers.


Prowall System

Ventilation Profile Base Bead

proboard ventilation profile and base bead
  1. ProWall Ventilated Base Bead mechanically fixed through sheathing into main timber studs
  2. Breather membrane to overlap ProWall Ventilated Base Bead
  3. 75mm x 25mm treated timber battens (class 3) fixed into main timber studs
  4. ProWall Base Bead, PWBB fitted to face of timber battens creates level at base of system and improves impact resistance

proboard ventilation and profile base bead

Battens To Apertures

proboard ventilation profile and base bead
  1. 75 x 25mm timber battens framing aperture to aid fire performance and board fixing pattern
  2. 50mm gap between vertical battens and aperture framing battens

Note: Detail ensures appropriate drainage and ventilation

Aperture Flashing

  1. Flashing tape applied beneath window frame and sill prior to window installation
  2. Flashing wrapped around the head framing batten and lapped up under breather membrane
  3. Flashing tape downturned at ends of opening to maximise drainage
Flashing Diagram

ProBoard Fixing

Proboard Installation

  1. ProBoard to be fixed in block bond style
  2. 3mm spacings required between ProBoards

Fixing Spacing

  1. Maximum 200mm centres between screws on general battens (subject to minimum number of fixings as outlined below), or 120mm at the corners.

Note: Adherence to BS 5268-2 for avoidance of batten splitting. Drawing assumes 600mm stud spacing.

Maximum Spacing of Timber Studs (mm)Minimum Number of Timber Frame Fixings per 2.4 m Long StudDesign Resistance against Wind Load kN

Elevation Layout

Aperture Planning

  1. ProBoard fitted around apertures to avoid vertical or horizontal joints at corners
  2. ProBoard joints minimum 150mm from the edge of opening

Corner Fixing

  1. Corner ProBoards fitted alternately block bond
  2. ProBead NMAB to be bedded on at corner during render application
  3. Corner Fixing

Fire Breaks

  1. Intumescent strip placed above horizontal slip joint creating cavity fire barrier
  2. Continual line of intumescent strip fixed with stainless steel screws
  3. Independent lengths tightly butted

Note: Firebreak detail is offered as a guidance detail only. All firebreak designs must be signed off/ approved by appropriate parties

Intumescent Fire Strip before and after.
Fire Barrier

Expansion And Slip Joints

Vertical Slip Joint

  1. Expansion joints in substrate to be mimicked in timber battens and ProBoard
  2. ProBead EX6 profile to be installed on surface of ProBoard

Horizontal Slip Joints

  1. Maximum 200mm centres on general battens (subject to minimum number of fixings as outlined below)

Note: Adherence to BS 5268-2 for avoidance of batten splitting. Drawing assumes 600mm stud spacing.




  1. Battens fitted at angle around service to provide drainage
  2. Treated battens required for hot flue
  3. Allow 50mm vertical batten spacings from framing battens
  4. ProBoard surface cut to accommodate service

System Ventilation

  1. ProWall cavity runs up to eaves with ventilated soffit panel
  2. Install intumescent strip at junctioN between ProWall and eaves to ensure appropriate compartmentalisation

Note: An alternate ventilation detail is available from the SAS Technical Team where a ventilated soffit is not available. Firebreak detail is offered as a guidance detail only. All firebreak designs must be signed off and approved by appropriate parties.

System Ventilation

ProWall Accessories

Ventilation Bead

ProWall ventilation bead provides protection at the base of the system against insects and rodents whilst allowing the cavity behind the ProBoard to breathe.

Base Bead

ProWall base bead provides protection to the base of the ProBoard whilst creating a level datum to install the ProBoard and a bellcast feature.

Window Protection

ProWall window protection bead ensures a clean line to the window frame along with a water tight seal and added protection during render application.

Noseless Mesh Angle

ProWall noseless meshed angle bead ensures clean yet concealed lines to external corners along with added protection to vulnerable areas.


  1. ProBoard joints should be taped using ProRend Lite and ProMesh Grade 3 mesh cut to 300mm wide strips.


  1. Using a Hawk and Trowel, apply a 3/4mm coat of ProRend Lite to the textured ProBoard surface.
  2. Embed ProMesh Grade 3 into the applied material.
  3. Overcoat with a 2/3mm coat of ProRend Lite.


  1. Elevations must be fully meshed with ProMesh Grade 3 reinforcement mesh.
  2. Ensure a minimum of 100mm overlap between mesh.
  3. Apply ProMesh Grade 3 in 300mm x 300mm squares at 45° to corners of all openings.
Mesh Layout

Ruling Off

  1. Using a spatula, rule off ProRend Lite to give a flat and even surface.
  2. The minimum finished thickness of ProRend Lite is 5mm.
  3. Allow ProRend Lite to cure for a minimum of 48 hours before applying other ProRend products.

ProRend Colourtex Primer

  1. Apply ProRend Colourtex Primer with a roller or brush ensuring complete coverage of the ProRend Lite basecoat.
  2. Allow to dry for 24 hours.

ProRend Colourtex Uniform/Grained

  1. Using a Hawk and Trowel, apply ProRend Colourtex decorative topcoat in a tight coat to the thickness of the aggregate within the material.
  2. A wet edge and uninterrupted application must be maintained at all times to avoid scarring.
  3. Allow approximately 10-30 minutes depending on conditions for material to ‘pick up’.
  4. Finish ProRend Colourtex decorative topcoat by rubbing with a smooth plastic float in either a horizontal, vertical or circular motion.

Application reference

  • For all ProRend renders BS EN 13914-1:2005 Design, preparation and application of external rendering and internal plastering; part 1, external rendering to be followed at all times.
  • Other advice and guidance is available in BS 5262:1991 Code of practice for external renderings, predecessor to BS EN 13914, and BS 8000-10:1995 Workmanship on building sites; code of practice for plastering and rendering.


  • Surface preparation requirements for ProRend renders are the same as for ordinary sand and cement renders. Surfaces must be clean, suitably dry, sound and free from anything that may interfere with the adhesion of the materials to be applied.
  • Only clean water fit for drinking should be used for gauging.
  • Scaffolding must be independently tied to allow uninterrupted application.
  • Masking should be used to give protection to adjacent work and to give clean straight edges. It should be removed immediately after finishing.
  • Remove splashes of material from glass or aluminium immediately as they may etch the surface and leave a permanent mark.
  • Walls should be protected from rain or other inclement weather during application and curing, ProRend renders should not be applied to substrates which are frost laden or have recently been exposed to prolonged rain.
  • When applying in hot weather, it is advisable to ensure that work coincides with the shaded areas of the building.
  • Local weather and site conditions must be taken into account by the applicator before any ProRend product is applied.


  • ProRend renders should be applied between 5°C – 30°C. Materials should not be applied if temperatures are expected to drop below 5°C within 24 hours.


  • ProRend materials applied to a render elevation should either be of the same batch number or thoroughly mixed together to ensure colour consistency.

Curing and Protection

  • Care must be taken to protect cement products from rapid drying conditions such as exposure to direct sunlight or drying winds. In these conditions it should be kept evenly damp for 3 - 7 days by lightly spraying periodically with clean water. This is to ensure complete hydration of the cement.
  • Polythene or Hessian sheeting is recommended during curing and should be arranged to hang clear of the face of the wall in such a way that it does not form a tunnel through which the wind
    could increase the evaporation of water from the rendering. Intermittent contact with the render must be avoided as this may cause a patchy appearance.


  • Cement based ProRend renders should be stored off the ground, under cover in dry conditions.
  • ProRend Resin renders should be stored in dry cool conditions at a temperature greater than 5 o C. Protect from sunlight and sources of direct heat. Containers should be kept sealed when not in use and stacked no more than four high.
Fire classification EN 13501-1A1
Compressive strength, N/mm215.5
Weight, kg/m214.65
Bending radius, m1.5
Thermal conductivity, W/mK0.196
Linear variation due to moisture, %0.05
Water absorption % by weight / 24 hrs<8
Freeze / thaw cycles100
General Information
Dimensions, m1.2 x 2.4
Thickness, mm12.7
Weight /sheet, kg42.2
Sheets / pallet33
Weight / pallet, kg1392
System weight, kg/m2~22