Dated 1313. Messy work 100ft up. DRY timber for repairs. Special flush washered nuts to look better.
Bad paint. late 1800s repairs rotted
Breathable lime render and lime paint
Trinity Timber Case Studies slideshare
Timberwork Case Studies MSc. Building Conservation 22 February 2013
Paul PriceWoodwrights Oak frame carpentry and timberconservation
An overview of historiccarpentry and timber repair Topics: 1.Recognising historic carpentry 2.Repairs: surveys and methods 3.Case histories
Historic timberwork Part of our built heritage – in Ireland: especially roofs. A valuable record of historic craftwork - timber conversion and scribe carpentry.Christchurch Cathedral, Dublin. 17th C. oakwork
Ilustrations from:McCracken, E. (1971) The Irish Woods Since Tudor Times
Timber Conservation Aims Conserve the overall aesthetic form of the structural frame while repairing the structure. Preserve original timber as much as possible. Timber surfaces, which preserve marks recording the original timber conversion and framing methods.Dunsoghley Castle, Co. Dublin.High quality scribe carpentry;Double collar;Arch-braces with locking tenons;Scribe numbers visible.
Timber Conservation Process Survey: historical value, condition, and structure. Repairs: minimal, unobtrusive, reversible. Outlook: maintenance check-listNorway - Loft repair.Timber replacement:New timber selected,cleft and hand hewnto match originaldecayed element.
Recognising historic carpentryConversion: logs into timberCarpentry: scribing, jointing and raising frames
Oak - tough and durable.Baltic pine – imported. Two forms of historic timberwork: Treewrightingaxe-hewn, boxed heart, often smaller ‘stuff’, cottage roofs; Frame carpentry hewn plus rip-sawn, mortice and tenon,large range of scantlings, use of grown “bends”, larger, more durable buildings.
Hewing: Turning logs into timber. Marking and notching
Juggling HewingNotching Finishing with broadaxe
Hewing:Finishing- A broadaxe was used to give a flat finish
Close up ofhewn surfaceAxe nick marks Stop mark Note mutualangle of marks
Numbering: Usually Roman - chiselled or race-knifed
Recognising historic timberwork Hewn or pit-sawn surfaces Carpenters layout marks - scribe lines and references Mortice and tenon joints Chiselled numbers at jointsScribed joints - shoulders scribed to match irregularities
Surveys Record DrawingsBasic survey - Schematic timber drawings and photographs. Full Survey: Archeological level recording. EstimatingAnnotate basic survey schematics with current condition and possible repairs
Bishops Palace, Salisbury,Wiltshire, EnglandRoof by Francis Price 1726 Our repairs 1998
Cathedral Church, Cashel Nave roof 1780 Large span 46ft =14mTransition carpentry Diagnosing astructural problem. – Is it really a problem?
Cashel Cathedral Church Roof: • Queen post roof with king strut • Ceiling load has deformed roof
Repair Methods for Historic Timberwork •Steelwork: straps, flitch plates, cables, brackets, bolts, screws to secure joints and framing. •Carpentry: replacement timbers, patch and end repairs. •Resin: consolidation, packing, patch and end repairs. Beware the “honest” repairMaking repairs look distinctive from original work is often an excuse for unsightly repairs.
METAL REPAIRS:•Often cheapest and best if hidden or subtle- no disassembly needed•Reversible and easier. Unsightly if visible and poorly designed.•Use galvanised or stainless steel for repairs.
CARPENTRY REPAIRS•Potentially damagingdisassembly required forreplacement or endrepairs.•Requires high qualityrepair carpentry for goodresults.•Decide whether to matchconversion methods.•Use oak with oak etc.
End repairs• require carefulfitting andassembly• use dry timberwhere possible.• may have to usegreen -allow forshrinkage andlater tightening
New tenon repair - only possible if frame elements disassembled
Rafter notch joint reformed in resinRESIN REPAIRS:•Good for consolidating valuable decayed timber and for packingout steel repairs.•Bad for large end repairs. Can be very ugly.•Always use resin designed specifically for structural timber work.
Timber durability: Excellent if kept dry. Good if sheltered. Bad if continually damp.Exposed to weather for 600 years Leaking weathervane - king post decayed