Masonry Cavity Walls
URSA CAVITY BATTS are suitable for both full and partial fill masonry cavity walls and have BBA approval. Fully filled cavity wall systems offer the most cost effective solution for a given U-value and can easily achieve current and proposed Building Regulation requirements. Our new, longer CAVITY BATT means 12% fewer slabs to install and up to 50% more product per pallet.
Two grades of URSA CAVITY BATT are available;
URSA CAVITY BATT 32 - thermal conductivity 0.032 W/mK.
URSA CAVITY BATT 35 - thermal conductivity 0.035 W/mK.
BBA Certificate 09/4624.
Design
URSA CAVITY BATTS are suitable for both full and partial fill systems. The batts may be used in any exposure zone in walls up to 25m high.
Rainwater penetration may be avoided by ensuring the correct use of lintels and cavity trays with appropriate stop ends.
Work undertaken by the BRE has identified the importance of good workmanship and the following points must be carefully considered;
- Ensure the residual cavity is kept clean and free from mortar dropping and other debris.
- Clean the top edges of the URSA CAVITY BATTS and the wall ties before installing the next row of slabs. The use of a timber cavity board is recommended to help keep this area clean.
- Do not push slabs down into a partially built section of cavity wall as this may dislodge mortar and bridge the cavity.
- Small, cut sections of slab should be installed with the face against the masonry i.e. with the fibres running vertically.
- Carefully cut, rather than tear, the slabs to fit around wall ties and other penetrations that cross the cavity.
Installation
Download the detailed installation guide here
URSA CAVITY BATT 32 U-values
103mm brick, URSA CAVITY BATT 32, 100mm block & plasterboard on dab.
U-value (W/m²K)
| Block Type | 100mm | 125mm | 150mm | 175mm | 200mm |
| Aircrete Block (0.15 W/mK) | 0.24 | 0.20 | 0.17 | 0.15 | 0.14 |
| Light Agg Block (0.34 W/mK) | 0.26 | 0.21 | 0.18 | 0.16 | 0.14 |
| Medium Block (0.57 W/mK) | 0.26 | 0.22 | 0.19 | 0.16 | 0.14 |
| Dense Block (1.13 W/mK) | 0.27 | 0.22 | 0.19 | 0.17 | 0.15 |
For further information and more U-values see our technical brochure in the Documents section. Alternatively please contact URSA Technical Department.