Oakum
Oakum is a traditional, fibrous caulking material made from hemp or jute fibres, used in the construction of log houses and timber frames but also in sealing plumbing joint, it may also be typically soaked in pine tar (Stockholm tar) when used on boat building. It has been used for many centuries, it acts as a durable, flexible, and breathable filler to seal gaps in between construction timber members, providing some form of waterproofing.Today it is often replaced with sealants of tape products that are easier to work with and more efficient at sealing though not so good at breathing).
[edit] Related articles on Designing Buildings
Featured articles and news
The sad story of Derby Hippodrome
An historic building left to decay.
ECA, JIB and JTL back Fabian Society call to invest in skills for a stronger built environment workforce.
Women's Contributions to the Built Environment.
Calls for the delayed Circular Economy Strategy
Over 50 leading businesses, trade associations and professional bodies, including CIAT, and UKGBC sign open letter.
The future workforce: culture change and skill
Under the spotlight at UK Construction Week London.
A landmark moment for postmodern heritage.
A safe energy transition – ECA launches a new Charter
Practical policy actions to speed up low carbon adoption while maintaining installation safety and competency.
Frank Duffy: Researcher and Practitioner
Reflections on achievements and relevance to the wider research and practice communities.
The 2026 Compliance Landscape: Fire doors
Why 'Business as Usual' is a Liability.
Cutting construction carbon footprint by caring for soil
Is construction neglecting one of the planet’s most powerful carbon stores and one of our greatest natural climate allies.
ARCHITECTURE: How's it progressing?
Archiblogger posing questions of a historical and contextual nature.
The roofscape of Hampstead Garden Suburb
Residents, architects and roofers need to understand detailing.
Homes, landlords. tenants and the new housing standards
What will it all mean?


















