Harl
‘Harl’, also known as ‘harling’ (or lime harling), is a technique for weatherproofing the exterior of masonry buildings, traditional to Scotland and Northern Ireland. It is commonly found on Scottish castles as well as more common building types, and was favoured due to its practicality and suitability for the harsh, wet climate.
The term ‘harling’ derives from the action of hurling wet mortar at a solid wall. This is known as a ‘cast-on’ finish, as opposed to a floated base coat (traditional to England), or rough-cast work such as pebbledash. In Ireland, it is commonly known as ‘wet dash’.
Harling consists of a slaked lime and coarse aggregate mortar which is thrown onto a stone wall, using a slurry of small pebbles or fine stone chips. By embedding a pigment in this material, the need for repainting can be avoided. A specially-shaped trowel is used to throw and then press the material into the surface. Cast-on coatings tend to provide better resistance to weather as the mortar is better compacted and more uniform throughout its thickness compared to trowelled-on coatings.
As the harl is mostly lime render it cures chemically rather than by drying, to provide a weather-protective and decorative coating. Once the harl is set it can be lime washed in various colours.
[edit] Related articles on Designing Buildings Wiki
IHBC NewsBlog
Biodiversity Net Gain through UK Construction Projects
The Conservation Hierarchy is a new framework developed by the University of Oxford to help construction projects achieve Biodiversity Net Gain.
How Project Managers for Town Centre Developments can Balance Risk
Jacqueline Hughes, senior risk analyst at Equib, in pbctoday discusses how project managers for town centre developments can get their risk management strategies right.
Red Tape is Strangling our High Streets
A new paper from the Adam Smith Institute argues that the problem with the High Street has been totally misunderstood, saying that we need to reform restrictive planning rules and reject a policy of managed decline to reinvigorate our town centres.
Calculating the full cost of energy used by buildings
The Whole Life Cost of Energy (WLCoE) calculator – issued by government in BETA form – is intended to help building owners and operators to understand the full financial cost of the energy their buildings use, and welcomes feedback
England’s heritage worth £31Bn: New Historic England report
New research published by Historic England (HE) shows the value of heritage to England’s economy as it contributes to economic prosperity and growth through jobs in the heritage and construction sectors and from tourism.
Part of Roman wall in Chester Collapses
Investigations have begun into what caused part of Chester’s Roman city wall to collapse during construction work.
Audit on new housing in England: Design overwhelmingly ‘mediocre’ or ‘poor’
Though conservation professionals' skills in understanding, defining and explaining local character and architecture can help inform new residential design.
Historic England’s ‘21 Fascinating Places Listed in 2019’
Over 500 historic places have been added to the National Heritage List for England (NHLE) in 2019 and Historic England (HE) has showcased 21 highlights.
UK’s iconic first red public telephone box upgraded to GII*
The K2 prototype telephone box situated outside the Royal Academy in London – built as part of the 1924 competition that gave rise to the iconic design and first listed at Grade II in 1986 – has had its listing upgraded to Grade II*.
Historic England publishes guidance on BIM for Heritage
The second in a series focusses on developing the Asset Information Model (AIM).
High Streets Face a Bleak Future Without Rethinking Regeneration Strategies
Reflecting issues that will be encountered across the IHBC’s June 2020 Brighton School, think tank Centre for Cities argues for High Street success.
Take a look inside the first flat in the iconic Battersea Power Station
City A.M took a tour of the first apartment to be completed within the original grade II*-listed power station with designer Tim Boyd of Michaelis Boyd – which also designed the interiors for Soho House and the Groucho Club – and Battersea Power Station’s UK sales director Georgia Siri.