RKS would design the walls (loadbearing and non-loadbearing), roofs and floors of a complete building. Alternatively, roof and wall elements of it can be used individually with other non-SIPS components. For example the client wanting a truss roofing system in conjunction with masonry or timber frame/steel frame internal walls.
We design any flooring system, however the foundations must have specific tolerances as per guidance available from the our Technical Department.
The panels are lightweight compared to brick and block, at a maximum of 25 kg/m2, therefore they are ideal for use, where heavy constructions are not possible.
As with all construction methods, including traditional masonry/ cladding, a long lasting external weather proofing is also a necessary.
The System is not recommended for cellars or basement constructions.
Internal / Partition Walls
Where cabled services are required, it is recommended that they be fixed into a timber or steel stud wall. However, where cabled services need to be fixed to an internal wall that is constructed of SIPS there are two options;
- single layer of minimum 15 mm plasterboard on minimum 10 mm deep by 38 mm wide vertical timber battens; or
- double layer of minimum 12.5 mm plasterboard – the layer closest to the wall panel should be chased out to create a cavity for services. The second layer should be 12.5 mm plasterboard.
Where cabled services do not need to be fixed to the SIPS a single layer of 15 mm sound resisting plasterboard can be fixed direct to the wall panel.
NB Requirements for minimum thickness and number of layers of plasterboard will vary depending on fire rating required.
Before cladding SIPS, a non-tenting breather membrane is fixed direct to the wall panels. A minimum cavity of 25mm should be maintained between the breather membrane and the wall cladding.
The following are wall cladding options for SIPS:
- outer leaf of brickwork / stone, ensuring a minimum 50 mm cavity is maintained between the breather membrane and the brickwork;
- lightweight render coating carried on calcium silicate board which is supported by min. 25 mm deep by 50 mm wide vertical treated timber counter battens;
- feather edge timber boarding on min. 25 mm deep by 50 mm wide vertical treated timber counter battens;
- wall tiling mounted on tiling battens which are supported by min. 25 mm deep by 50 mm wide treated timber counter battens; and
- proprietary brick slip system supported by min. 25 mm deep by 50 mm wide vertical treated timber counter battens;
If other wall cladding options are being considered, contact RKS Technical Department.
Separating Walls (Party Walls)
Robust Standard Details are available but typically, party walls are manufactured from kiln dried timber stud components. Both timber frame wall panels that form the separating wall should be lined internally with (in order of application):
- 19 mm gypsum plank and 12.5 mm vapour check plasterboard*; or
- 2 x 15 mm sound resisting plasterboard.
All SIPS roof panels should be lined internally with vapour check plasterboard*.
Where services need to be fixed on a roof panel, there are two options for creating a service cavity:
- single layer of 12.5 mm vapour check plasterboard* on min. 10 mm deep by 38 mm wide vertical timber battens; or
- double layer of 12.5 mm plasterboard – the layer closest to the roof panel should be chased out to create a cavity for services. The second layer should be 12.5 mm vapour check plasterboard.*
Where services do not need to be fixed to the roof panel, a single layer of 12.5 mm vapour check plasterboard* can be fixed direct to the roof panel.
Before cladding the SIPS roofs, a non tenting breather membrane should be fixed direct to the roof panels. Some cladding options available for SIPS Roofs are:
- tiles on tiling battens;
- slates on slate battens; or
- profiled metal sheeting onto horizontal battens.**
All roof cladding options should be supported by 38 mm x 50 mm vertical treated timber counter battens. If other cladding options are being considered contact RKS Technical Department.
The roof cladding option should be decided upon at the earliest opportunity, as loading design values must be calculated when designing your project in SIPS.
*Calculations in accordance with BS 5250: 2002 (Code of practice for control of condensation in buildings) will determine whether there is a requirement for a vapour control layer with the SIPS System. However, it is always good practice to install a vapour control layer as buildings have a tendency to alter their psychrometric conditions (relative humidity) through change of use.
This can be installed in the conventional manner, using 500 gauge polythene sheet, or by using vapour check plasterboard.
**The need for battens may be negated with the use of a suitable breathable underlay.