ProWall is ideally suited to timber frame construction and the strength of our detailing has been supported and developed with key partners including the NHBC and UKTFA. The following is a guide to ProWall when used over timber frame structures. Commonly overlooked but important features are included, such as:

• Fire breaking detail
• Batten dimensions (75mm x 25mm) to ensure fire protection and avoid splitting of battens during fixing
• Shrinkage movement joint

CAD features are illustrative, however it is recommneded that full specifications be sought for your project from the SAS Technical Team. 

Ventilated Battened Cavity (Base of System)

1. ProWall Ventilated Angle Bead mechanically fixed through backing board into main timber studs
2. Breather membrane overlapping ProWall Ventilated Angle Bead
3. 75mm x 25mm treated timber battens (class 3) fixed into main timber studs with ProBoard stainless steel fixings

Note: Detail creates ventilation whilst ensuring drainage at base of system. NHBC Standards state minimum 15mm cavity in any one area for stated scenario

Fully Framed Openings 

1. Timber battens framing aperture to aid fire performance and board fixing pattern
2. 50mm gap between vertical battens and aperture framing battens
3. 15mm - 20mm gap in breaks between continuous vertical timber battens 

Note: Detail ensures appropriate drainage/ventilation

Flashing tape to openings for drainage

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

Casing bead as datum for proBoard

1. ProBead PE12 fitted to face of timber battens creates level at base of system and improves impact resistance
   

ProBoard rainscreen fixing pattern 

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

ProBoard Standard fixing pattern

1. Maximum 200mm centres on general battens (7-8 fixings)
2. Maximum 120mm centres on corner area battens (9-10 fixings)

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

anti crack board configuration

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

Corner anti Crack board configuration

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

fire compartmentalisation of flues and vents

1. Battens fitted square around service 
2. Fire treated battens required for hot flue 
3. Continue 50mm vertical batten spacings from framing battens 
4. ProBoard surface cut to accommodate service 

Vertical Expansion Joint (timber frame) 

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

Note: Detail indicates party-wall in timber frame

horizontal slip joint for timber frame shrinkage

1. Shrinkage allowance provided in timber battens and ProBoard 
2. No battens should be fixed into floor zone; battens should 'float' over the rim board to enable cantilever
3. ProWall Slip Joint profile installed over surface of ProBoard
4. Typically this detail incorporates Fire Break as below to ensure compartmentalisation

Note: Where no horizontal movement joint or vertical expansion joint exists provision should be made within the ProBoards so that no area exceeds 42m^² or 7.5m (linear) without a break

Intumescent fire break for timber frame (floor level)

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

Ventilated battened cavity (ventilated soffit)

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

Information is indicative of SAS specification. Full specifications and CAD detail should be sought prior to specifying the ProWall system.

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