Timber beam-end engineering repairs - Resin bonded cross
Click on any of the images for a larger view.
The Problem
A timber framed, indoor market hall. During extensive refurbishment by a major building contractor, it became apparent that the principal post to the truss had suffered from a wet rot attack. The source of moisture was from a defective lead flashing under the dresser light. Past repairs to the purlin bearing ends had resulted in a flitch post being bolted to the principal post. Since the water was still getting in, both post and repair suffered further decay.
There were six posts to be repaired. As each one was suffering to a greater or lesser degree, I decided to use a standard repair system to conform to the specification. I will show the procedure of just one timber repair system.
The basic idea was to return the post and purlin system back to its original form. Working closely with Property Repair Systems ensured that the repair and manufacturing process was a smooth operation.
Trusses requiring remedial work.
Timber Repair System manufactured - sorry about the poor picture quality!
Scaffolding requirements.
Once the fascia board and electrical conduit was removed the posts and purlins were fully exposed.
The first stage of the operation was to drill out a horizontal slot, so that it could accept a 20 mm bar, through the post and purlin to a length of 2 metres.
Next the decayed purlin ends were cut back 100 mm, ensuring that all the rot was removed. At this point the timber bolted flitch plats were disconnected. Note the rot to the rear of the post.
We established that the upper section of the post was free from fungal attack, mainly because it was protected by the external fascia board. This was quite fortunate, as we could rely on the existing joints and tie bar fixings to remain in place.
The timber was marked out for the positions of the fibre bars.
Slots were drilled into the post face.
The slots were cleaned out. The depth of slot left a 10 mm face at the back of the post, to retain the resins.