Timber & Metal Frame Walls

URSA TIMBER FRAME ROLL 32 - thermal conductivity 0.032 W/mK.

URSA TIMBER FRAME SLAB 32 - thermal conductivity 0.032 W/mK.

URSA TIMBER FRAME SLAB 35 - thermal conductivity 0.035 W/mK. 

URSA HOMETEC ROLL 35 - thermal conductivity 0.035 W/mK.

Design

URSA TF ROLL/SLAB is suitable for both timber frame walls and URSA HOMETEC ROLL 35 is used in metal stud walls. They may be used in conjunction with insulated plasterboard internally or cavity insulation (sheathing) to achieve very low U-values.

A vapour control layer is generally required when insulating between the studs, this can either be a polythene sheet (minimum 500g) or a foil-backed plasterboard. When using sheathing insulation the structural frame is maintained at the same temperature as the inside of the building and a vapour control layer may not be required.

The use of both a vapour control layer (internal) and a breather membrane (external) creates an air barrier that helps to improve the air tightness of the building and so limits air infiltration.

Rainwater penetration may be avoided by ensuring the correct use of lintels and cavity trays with appropriate stop ends especially when using sheathing insulation or at changes in the wall construction.

Insulation between the timber or metal studs introduces a series of repeating thermal bridges that must be accounted for in the U-value calculation procedure - the default in timber frame is to use 15% bridged proportion. The addition of internal or external (sheathing) insulation can help to reduce this effect by masking the thermal bridges.

Installation

Insulation Between Timber Studs

1. The timber frame, OSB or plywood sheathing, breather membrane etc are all installed in the normal manner.
2. The external finish of brickwork, tile hanging or external render is then installed.
3. The URSA TF ROLL/SLAB is fitted tightly between the studs, normally fully filling the stud depth.
4. The internal lining of air and vapour control layer (AVCL) and plasterboard are then fixed in the normal manner.
5. An enhanced U-value may be achieved by installing additional insulation internally or externally to the timber frame. Check with the timber frame manufacturer for specific requirements and details.

Insulation Between Metal Studs

1. The metal framing is installed in accordance with the manufacturer’s instructions.
2. The external finish of brickwork, tile hanging or external render is then installed.
3. The URSA HOMETEC ROLL is cut to size to suit the stud centres (normally 600mm) and fitted tightly between the studs, fully filling the stud depth.
4. The internal lining of air and vapour control layer (AVCL) and plasterboard are then fixed in the normal manner.
5. An enhanced U-value may be achieved by installing additional partial fill cavity wall insulation external to the steel frame. Check with the steel frame manufacturer for specific requirements and details.

Other forms of external finish such as tile hanging, render, timber weatherboarding, PVC-U cladding etc are also suitable and should be fixed in accordance with the manufacturer’s instructions.

URSA TIMBER FRAME ROLL 35 U-values

For further information and more U-values see our technical brochure in the Documents section. Alternatively please contact URSA Technical Department

Industry information

Sources of useful additional information