Ashlar Lime Mortar

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A fine grained lime mortar for building and pointing tight joints in brick or stone. Available in a range of colours.

Ashlar mortar is perfect for laying bricks and cut stone on a tight bed of thin mortar, made using natural hydraulic lime, sand and stone dusts it has excellent water retention and does not rapidly dry when trying to position the stones. This mortar is generally suitable for joints of between 3 and 6mm, for both renovation and new build, and only requires the addition of water. 

Packing and availability

Available in 25 kg paper sacks. All colours are made to order.

Yield

Fresh bulk density: 1750kg/m3 +/-100kg

Yield: approx 65 to 75 25 kg sacks per m3 of mortar

Mixing

Add full bags of Lime Green Ashlar Mortar into a drum mixer. Avoid creating excessive dust. Add approximately 5 litres of clean water. Pour the water in slowly as the product mixes, using just enough to achieve the correct workability. Mix for between 3 to 10 minutes. Lime Green Ashlar Mortar may be reworked up to 8hrs after adding water. Please contact us for further information.

Curing

Hydraulic lime starts to set once water is added and also hardens by reacting with carbon dioxide, which is a slow  process. Prevent rapid drying by protecting the mortar against the effects of drying winds, strong sunlight, rain and frost with mortar fleece or hessian. In warm weather gently mist spray with water after application and cover if required with damp hessian sheets. In cool weather cover fresh mortar with protective sheeting to help avoid frost damage. Do not allow freshly mortar to freeze after laying until it has dried and gained strength.

Please note that colours on screen may vary from actual finishes.

Use this colour chart to narrow your choice of finishes then get in contact with us for your your colour samples

Tallow

Bath

Cotswold

Ochre

York

Purbeck

Bracken

Stone

Barley

Corfton

Harnage

Earth

Terracotta

Salmon

Tugford

Farringdon

Birch

Cinders

Chalk

Please note that colours on screen may vary from actual finishes.

Use this colour chart to narrow your choice of finishes then get in contact with us for your your colour samples

 

The Project: The Bomber Command Memorial

Britain's Bomber Command played a significant role in the Allied victory of the Second World War, a contribution not recognised with a national memorial until June 2012. Then, in London's Green Park, the Queen unveiled The Bomber Command Memorial, in commemoration of the 55,573 who gave their lives during the 1939-1945 conflict.

The Requirement

To echo the distinctive white-grey limestone appearance of London's major public buildings such as St Paul's Cathedral, Buckingham Palace and the Cenotaph in Whitehall, Portland Stone was chosen as the predominant material for The Bomber Command Memorial. It is also the same stone that the Armed Forces Memorial at Alrewas in Staffordshire is made from.

Given its historic significance, the memorial has to be robust enough to stand the test of time, and remain in great condition, despite all that a busy London can throw at it.

The Problem

  • Portland Stone is much softer than concrete and modern day bricks, so it requires a high quality lime render that will have not only durability and a good surface finish, but also the flexibility and porosity to ensure that it does not crack or shrink. To have used strong, rigid-setting Portland cement (which has nothing to do with the Isle of Portland where Portland Stone comes from), could have proven potentially disastrous.
  • The lime mortar used would need to be an exceptional colour match to the stone blocks for the monument to have the appearance of a one-piece unit.
  • The lime mortar would also have to meet the demands of structural engineers who required both strength and speed of setting to meet their deadlines.
  • The site where the memorial was being built was both short on space and logistically difficult to service, being right in the heart of London where deliveries at peak times are restricted.
  • Some of the joints in the block were very fine and would need a correspondingly fine lime mortar to look their best.
  • Portland stone columns used in the structure would be difficult to bed down solidly on mortar alone.

The Solution

Given Lime Green's previous expertise and experience working on major developments in London, the mortar consultants on the project stipulated us as the preferred supplier. For The Bomber Command Memorial, we supplied three different products in all:

  • Several hundred tonnes of standard mortar, 'tweaked' to become Bomber Command Mortar Number 1 and used for all brickwork areas.
  • A very specific ashlar mortar, which with its very fine texture could be used in the thin joints of the beautifully carved stone blocks.
  • Grout that was poured into the columns to provide structural strength, rather than trying to keep heavy stone blocks balanced on soft beds of mortar.

 

Image showing positioning of The Bomber Command Memorial columns at London’s Green Park. Materials including Portland Stone and Lime Mortar - Lime Green

The Benefits

  • By carefully testing and mixing mortars we were able to achieve the exact colour match necessary to ensure there are no tell-tale lines breaking up the blockwork.
  • Since lime is able to accommodate movement, it will flex as required, so there won't be any unsightly cracking of mortar.
  • The quality of our lime mortar means that the memorial will stay looking good over a very long time.
  • Given that delivery was often time-critical, materials were delivered in 25 kg bags or one tonne bulk bags. This meant quick offloading onto a tight site, enabling trades to keep working to meet their tight deadlines.

 

Since being unveiled by the Queen, The Bomber Command Memorial has become a major tourist attraction and a moving experience for many who visit it.