Specialist Timber Beam Repair - headed carved beam end repair
Initially the beam looked as though it just needed the bearing end to be renewed, but as the inspection proceeded it was found that the central section of the beam was missing and a test along the length of the beam showed a phenomenal loss of timber as far as 1.8 metres from the damp wall.
This was a hand carved oak beam. Prior to our visit the fungi had been removed from the external face of the timber, making the diagnosis a bit more of a challenge.
We took into account the following: timber species was oak; persistent water had been present; bleached timber appearance; stringy white fibres; no cuboidal cracking; easily crushed decayed wood; damage only to the interior of the wood.
It could only have been a wet rot known as Donkioporia expansa, a white rot found only rarely and normally in very old buildings such as churches. It was disturbing that others had looked at the beam and not tested its strength.
Click images for a larger view.
Photo of beam end showing initial propping by client, no visual deterioration in the beam.
No real visual signs of rot.
Inspection. Tests were carried out to the timber beam by inserting a 10 inch screwdriver to the beam. This showed no resistance up to 1.8 metres from its bearing end. Survey report and recommendations submitted to client.
Start of works. Photograph of Donkioporia expansa fruiting body.
Above & left Donkioporia expansa fungi on timber.
New beam bearing end manufactured by Property Repair Systems.
Start of the slotting system to the parent timber.
Constructional detail.
Cut off section of parent timber ready to accept new bearing end.
Lifting gear providing support to bearing end prior to being cut off.
Cutting off beam end.
Cross section of parent timber.
Bearing end cut off and being safely lowered to ground floor level.
New beam bearing end being treated with heavy duty preservative paste.
Final location of splice.
New beam bearing end being lifted into position.
First dry fit of bearing end.
Condition of beam end that was located within the masonry.
Donkioporia expansa fruiting body
Alignment of slots from parent timber to new bearing end.
25 mm steel reinforcement bars.
Base coat resin to bottom slots.
All resins and steels installed.
Overall view prior to structural props being removed.
Joist connections re-established to beam.