Perpend
The term ‘perpend’ (perp or cross joint) refers to the vertical joints between blocks or bricks that have been laid in a horizontal course to form a wall. Perpends are normally filled and sealed with mortar. The horizontal mortar joint in a wall construction is typically referred to as the bed joint.
Rather than being filled with mortar, perpends may also be left open to form weep holes or cavity ventilators. These provide openings that allow the drainage of moisture from within a wall construction and allow ventilating air to the back of a wall to help prevent mildew, dry rot and damp. They are generally formed by plastic inserts into the perpends, as these form a more uniform opening compared to simply leaving a void. See weep holes for more information.
A perpend stone is a long stone that extends between the inner and outer layers of a stone wall, tying the two layers together. The stone is ‘dressed’ at both ends.
The term ‘perpend’ may also be used more generally to refer to any brick or stone the longest dimension of which is perpendicular to the face of the wall. See bond stone.
The expression “keeping the perpends” is a term used to describe what happens when cross joints or transverse joints in brickwork are maintained in a perpendicular line.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
About the 5 Percent Club and its members
The 5% Club; a dynamic movement of employers committed to building and developing the workforce.
New Homes in New Ways at the Building Centre
Accelerating the supply of new homes with MMC.
Quality Planning for Micro and Small to Medium Sized Enterprises
A CIOB Academy Technical Information sheet.
A briefing on fall protection systems for designers
A legal requirement and an ethical must.
CIOB Ireland launches manifesto for 2024 General Election
A vision for a sustainable, high-quality built environment that benefits all members of society.
Local leaders gain new powers to support local high streets
High Street Rental Auctions to be introduced from December.
Infrastructure sector posts second gain for October
With a boost for housebuilder and commercial developer contract awards.
Sustainable construction design teams survey
Shaping the Future of Sustainable Design: Your Voice Matters.
COP29; impacts of construction and updates
Amid criticism, open letters and calls for reform.
The properties of conservation rooflights
Things to consider when choosing the right product.
Adapting to meet changing needs.
London Build: A festival of construction
Co-located with the London Build Fire & Security Expo.
Tasked with locating groups of 10,000 homes with opportunity.
Delivering radical reform in the UK energy market
What are the benefits, barriers and underlying principles.
Information Management Initiative IMI
Building sector-transforming capabilities in emerging technologies.
Recent study of UK households reveals chilling home truths
Poor insulation, EPC knowledge and lack of understanding as to what retrofit might offer.