JAM Structural Design

Designing out cold bridges!

When a steel beam is supported directly by masonry, the load can be too concentrated, often leading to cracks. That’s why we design in a bearing solution: placing the beam on a concrete padstone to help spread the load safely into the wall.

But it’s not just about strength. It’s also about thermal performance.

A cold bridge is a route through which heat from the inside of the building can make its way outside without meeting any insulation to stop it.

In this case, the external walls of the existing house are masonry with a very small uninsulated cavity.

We are proposing to insulate around the beam with either rigid insulation or a Farrat thermal break plate. This can then sit on the concrete padstone. To prevent heat from crossing the cavity we are suggesting 10-15mm of Aerogel insulation, which offers a lower thermal conductivity than PIR for the same thickness.

We’ll be working closely with the architect to develop the detail and make sure it works both structurally and thermally