Cavity wall ties

Building surveys often report that cavity wall ties may be corroded. Of course the only way of finding out for sure is having a look. If you have a camera on a stick you could drill a hole and investigate.

You could of course ask for quotes from cavity wall tie firms, but these have a vested interest in selling their service. Costs vary.

There is an alternative apparently – something I’ve not heard of before:

The alternative is to inject polyurethane foam into the cavity. This glues the two walls together avoiding the need to replace the wall ties.

The polyurethane foam then also insulates the cavity and is supposed to be twice as good as blown mineral wool fibre or polystyrene bead. Polyurethane is also impervious to water so won’t be affected by flooding or water ingress.

Isothane Technitherm and BASF WallTite are tow companies which offer this service. Have never heard of this before though – have you had cavity wall ties replaced or new ones put in or tried this new system?