The term ‘Crosswalls’ refers to Rationalised Traditional Construction (RAT-Trad) and includes over 70 different house types across the UK. These homes were a mix of traditional and non-traditional construction methods. The end gable and separating party walls were built out of traditional block and brick construction whilst the front and rear elevations were typically formed from a timber frame which was then boarded / sheathed using a variety of materials often including plywood or asbestos panelling.
- Only the gables and party walls needed to be built on-site.
- Layouts, dimensions and details of the infill panels could be standardised and produced off-site.
- Some existing timber frame non-traditional systems could be incorporated too.
- This meant the panels only required assembly on-site.
- The only additional site requirements after installation were the addition of glazing and doors.
Areas of Concern
- Seals, joints and damp-proof course all need to be checked as do the wall ties.
- Any cavity insulation will be ineffectual.
- The timber framed front and rear elevations can move excessively under lateral wind loads and also suffer from significant air leakage.
- Existing cladding or sheathing should be inspected.
With any project, the first step is always a structural survey. Once this has been carried out, our technical team are in the perfect position to advise on the right system for the project. For Crosswall homes, we recommend our “hybrid” system, which uses a standard EWI solution alongside a Structural EWI (SEWI) cage system:
- Standard EWI system can be used on the gable end walls, where the structure of the house is the most stable.
- Our Structural EWI system can then be installed to the front and rear timber frame faces. Fixed directly to the existing substrate, the Structural EWI system is designed to span any existing cladding and fix into the actual timber frame itself.
- The added benefit of the Structural EWI system is that it’s going to significantly reduce deflection and enhance the rigidity in these areas which are often weak and flexible.