Joining a Divided Erf
- Location: Cape Town, South Africa
- Status: Complete
A successful bridge demands the perfect unity between structure and form; a perfect challenge for our multi-disciplinary practice. Glen Cottage is on a divided erf; the house is cut off from its garden by a perennial river.
The decision to span the stream with a structure made of timber was to embed the bridge in its tree locale and follow on the firm’s commitment to sustainability. Cladocalyx, a Eucalypt commonly known as sugar gum, is grown in the Western and Eastern Cape and exceeds the performance of unsustainable imported hardwoods in terms of durability, strength and hardness. It is sourced sustainably from local alien clearing programmes and does not require pest or solar treatment, greying over time.
Eucalypt exceeds the performance of unsustainable imported hardwoods in terms of durability, strength and hardness.
A sample bridge section was made up to explore proportions, steel fixtures and gain client approval. Finally the timber members were cut and assembled much like a meccano set on site. The timber bridge was erected in 5 days.
The structural depth of the two main beams spanning 8m and weighing 360kg each is kept to a minimum (310mm deep) by utilising cladocalyx beams rather than trusses (or laminated pine), in-plane bracing and moment transferring support connections to the concrete buttresses. Consistent rebates in material detailing including the stainless steel stanchion capping and cutting back of concrete elements in section architecturally thrusts the bridge across the stream; gathering each side of the property together and making them one.
- Team: Collis/ Irvine/ Wickins