Cements Works

Cement & Lime Works

Harling (dry dash)

When carrying out a harling job we always strip back to brick ensuring a proper adhesion to the property and a long lasting job compared to scratch coating over existing harling / rendering which will, become boss and fall of

Key types of harling & Finishes

  • Traditional Lime Harling (“As Cast”): The most authentic, traditional finish. A mixture of lime mortar and aggregate is thrown (“hurled”) onto the wall, leaving a rough, uneven, and highly durable surface.
  • Pressed/Floated Harling: The cast mortar is gently pushed back or smoothed with a timber float to create a flatter, more even surface. This was often done on more formal 18th/19th-century houses, sometimes lined to look like ashlar stone.
  • Roughcast (Wet Dash): Similar to harling, but the mix (usually cement) is thick and contains the aggregate, which is then thrown onto the wall. The finish is very chunky and rustic.
  • Dry Dash (Pebbledash): A common modern variant where dry aggregates (spar, chippings) are thrown onto a wet mortar base coat (cement or polymer) rather than being part of the mix.
  • Cement/Polymer Render: Often used on modern buildings for enhanced strength and flexibility over lime, reducing crack risks while offering a similar texture.

Lime harling is generally preferred for historic buildings to allow moisture to escape, while cement is better suited for modern, non-breathable structures.

Harling East Lothian

Roughcast (wet dash)

Key Aspects of Roughcast Render:

    • Composition & Application: Unlike pebble dash, where stones are thrown onto wet plaster, roughcast involves mixing aggregate into the wet mix before applying it to the wall. It is often applied in a two-coat process: a scratch coat followed by a wet dash coat.
    • Appearance & Benefits:
       It offers a rough, decorative textured appearance and is known for being extremely durable, weatherproof, and relatively low-maintenance.
  • Uses: It is commonly used for weatherproofing houses, particularly in rural areas or on older, traditional properties (especially in Scotland and Northern England). It can also be used to conceal poor-quality masonry or to add a decorative finish to modern buildings.
  • Materials: Common aggregates used in roughcast include granite, cream dolomite, and quartz chips, often in 6mm sizes.
roughcasting edinburgh
LIME POINTITNG EDINBURGH

Lime Pointing

Lime pointing is essential for traditional, historic buildings because it is breathable, flexible, and sacrificial, allowing moisture to escape and protecting softer brick or stone from damage. It typically uses a mix of lime (putty or NHL) and aggregate, applied by hand to damp joints and finished with a brushed or rustic look.

Common Types of Lime:

Lime Putty (Non-Hydraulic) Very soft, cures by absorbing carbon dioxide over a long period. Ideal for traditional, porous bricks and softer stone.

Natural Hydraulic Lime (NHL): Sets in the presence of water, making it stronger. NHL 2 or 3.5 is generally used, with NHL 5 reserved for very exposed, wet conditions.

Key aspects of Lime Pointing:
 
  • Breathability & Flexibility: Unlike cement, lime mortar allows moisture to evaporate from the wall, preventing damp issues. Its flexibility allows the building to move without cracking, whereas hard cement can cause the edges of stones/bricks to break (spalling).
  • Sacrificial Layer: The mortar is designed to be weaker than the surrounding masonry, meaning it wears down first, making future repairs cheaper and easier than replacing damaged stone or brick.

Ridge & Hip Pointing

Key Aspects Ridge & Hip Pointing:

  • Purpose: It fixes tiles to the ridge, keeps them watertight, and prevents damage during harsh weather.
  • Materials: Traditionally sand/cement mortar is used, but it can crack over time. Flexible roofing compound is increasingly used for its ability to prevent future cracking and provide a 10-year guarantee.
  • Method: Involves cleaning out old mortar, ensuring the tiles are stable, and applying the new material securely. If tiles are loose, they may require “re-bedding” (resetting the entire tile) rather than just pointing.

What we do:

  • Ridges
  • Hips
  • Ridge Re-bedding

Maintenance free dry ridge and hip system

Traditional mortar based ridge and hip systems can be upgraded to a dry ridge and hip system eliminating the need to repoint these areas ever again.

  • Colours to suit all properties
  • Breathable dry ridge systems helps vent the roof space
  • Maintenance FREE for life
ridge pointing east lothian