Firth RibRaft® Floor System
- CM70056 Rev2
- Valid from
- Bureau Veritas
The Firth Ribraft® Floor System comprises of polystyrene pods, steel reinforcing, plastic spacers and Firth Ribraft® concrete. The system consists of the following components:
- Ribraft® Polystyrene Pod 1100mm x 1100mm x 220mm. 300mm thick pods are also available for deeper edge beams and internal ribs
- Firth Pod and Reinforcement spacer (300mm and 100mm)
- Firth Reinforcement chair
- Reinforcement Grade 500E
- Mesh reinforcement
- Firth Ribraft® Concrete 20 MPa or 25 MPa
- Sand blinding
- DPM (250 micron polyethelene sheet)
The Firth RibRaft® Floor System is a method of concrete floor construction, suitable for all slab-onground concrete floors for domestic or residential buildings that fall within the scope of NZS 3604:2011 Timber framed buildings.
Subject to the following conditions and limitations:
1. The Firth RibRaft® Floor System shall only be used in buildings which fall within the scope of NZS 3604:2011 – Timber-framed buildings, located:
- Where the Seismic Hazard Factor Z (defined in NZ 1170.5) is less than or equal to 0.45 (refer to Figure 6 of the Firth RibRaft® Technical Manual January 2020)
- in any wind zones up to and including Extra High
- in areas with snow loads up to 2.0 kPa
- in all exposure zones (except microclimates)
- and where the ground Ultimate Bearing Capacity exceeds the value specified in Table 2 for the types of construction in Table 1 of the Firth RibRaft® Technical Manual January 2020.
2. The Firth RibRaft® Floor System must be designed and installed in accordance with the Firth RibRaft® Technical Manual January 2020.