Roof in danger of collapsing.

Danger of roof collapse. Identified by Peter Weddell owner/operator of Qld Home Buyers Inspection service and Queensland Building Inspection Service, QBIS.

Danger of roof structure collapsing

A tiled roof supported off an undersized ceiling beam (binder) which is also causing sagging of the ceiling joists below.

This is a common fault with roof structures of many homes built in Brisbane around the 1940’s through to the 1980’s.

Danger of roof collapsing

With no support between the props this under-purlin is sagging considerably. Without rectification this can cause the roof to collapse.

Barap Bolt roof support

The danger of roof collapse could easily be rectified by fitting of a Barap Bolt. These were used where support of the roof could not be achieved off an interior wall.

What is a Barap Bolt?

  • A threaded rod fitted below an under-purlin with props for support between the rod and purlin.
  • Brackets are secured to hips, underpurlins or rafters where props are placed below the brackets for support, off the internal walls.
  • Support must be fitted below ends of the Barap Bolts brackets where they are secured.
  • Occasional retensioning of the rods nuts are required to help alleviate sagging of the roof.

Although no longer manufactured, they can easily be fabricated by an engineering business.

Roof collapsing danger

Danger of roof collapse.

They don’t build them like they used to!

A poorly constructed roof structure above a Post War house, in a southern suburb of Brisbane.

  • The main beam (binder) supporting this roof is fractured considerably and dangerous!
  • Binders are not designed to support any part of a roof.
  • Others photos show significant sagging from inadequate support.
  • Roof structures must be supported off the internal walls (where possible) otherwise indirectly by other means of construction.

An extremely dangerous situation that required immediate restructuring of the roof.

Alternate solution:

Rather than restructure the roof, it would be worth considering replacing the concrete roof tiles with metal sheeting. This would reduce the roof weight considerably and may only require more securing of the roof structure (for tying down).

Some related material that may be of use:

Queensland Government Technical notes on roofing

For independent Building Inspections Brisbane in all suburbs, Qld Home Buyers Inspection Service. qbis.com.au