Heavy Oak Carpentry and Cob, Wattle and Daub

These trades are inextricably linked. The Heavy Oak Carpenter and the Dauber often have occasion to be grateful to the other

Heavy Oak Carpentry

There are many ways of repairing Heavy Oak Carpentry. A real problem is finding seasoned oak in sizes to match the existing. Oak thicker than 4” does not kiln dry readily. Surface case hardening can cause cupping and extreme shaking

Carpentry Repairs : These are possibly the most intellectually and emotively satisfying. Steel reinforcement is usually essential as unseasoned oak does not take glue well and shrinkage of the new loosens even the best made joint. The longer scarf joints are deeply wasteful of sound original timber, however pleasing visually. Even the finest joints become clumsily undersized as the new oak shrinks and it may be necessary to consider oversizing the new by some 3% tangentially to 7% radially to compensate. Inevitably, this too looks clumsy initially, however well intentioned or sound in principle. A degree of unwanted dismantling may be necessary to “rear” a repaired timber into place unless the design allows for slip tenons or shouldered mortices Cheap Street White Heart Llanfihangel

Steel Repairs: Arguably steel is the most economical and philosophically sound repair. The very minimum of original timber is lost, the repairs are cheap, easily wrought in situ without dismantling as they are “augmentative”, and strong, without being rigid. They can offend because all too often they are designed without concession to visual aesthetics and the traditionally trained carpenter may have an instinctive prejudice against an alien material Bettiscombe Manor

Laminated Repairs: Crafting the most complex of repairs in situ by cutting out the decay only, and graving in glued up laminates of all shapes and sizes overcomes the problem of finding seasoned oak and encourages real sophistication and strength in design. Like steel repairs, they barely disrupt the structural integrity of the timber frame. However they are expensive, unforgiving if poorly executed, and their “plywoody” quality can be hard to hide Yelde Hall

“Open Heart” Repairs: This technique is used to save valuable surfaces, be they carved, painted or just beautifully patinated. The original surface however decayed is carefully sliced away from its structural heart, and re-adhered to a new, usually laminated, one. The decayed surface may be pre-consolidated with resins to enable it to survive the upheaval of what can best be described as “Open Heart Surgery” More so than any other, they preserve the character and “feel” of the building

Resin Repairs: Carbon or glass fibre, steel or similar reinforcement in secured in the heart of surviving sound timber and embedded in a resin matrix that may or may not successfully match the form and surface appearance of the original timber which has been lost. These are not repairs that should not be experimented with externally, but can be useful and, if skillful handled, relatively unobtrusive

St Blaise uses all these methods, consideredly, and in context

Case Studies in Timber Frame Repairs

Cob, Wattle and Daub

Be it wattle and daub, pise de terre or rammed or stabilised earth, cob, clob, or clom, chalk cob or wichert, mud and stud, clay lump or adobe, or any other regional variation, the repair principle is the same. Mud buildings shrink enormously on drying. Repairs cannot be cast in situ, they fall away on drying. Like laminated repairs in Heavy Oak Carpentry, earth buildings can only be repaired effectively by cutting out and piecing in with new, pre-dried and shrunk, “briquettes” of the same material, bedded on the finest sieved slurry of the original material. The repairs can be scraped back such that they barely show

St Blaise is a West Country firm. We are familiar with the startling red cobs of Devon, the softer yellow ones of most of Dorset, and the extraordinarily white, hard and durable chalk cobs of Wiltshire and Hampshire

Case Studies in Cob