Lime Rendering / Lime Wash

Lime rendering is a traditional method of smoothing over imperfections on external walls of a structure or building. Render can be applied to follow the undulations of an underlying substrate, or applied in layers to provide a smooth final coat. The finish can be left as is, or further enhanced with a pigmented Lime Wash to add some colour.

The advantage of using lime over modern cement based materials is that it remains flexible enough to allow slight movement in a buildings structural core, and is breathable allowing the ingress and egress of moisture with the seasonal variations of precipitation and temperature. Cement based renders on the other hand set hard providing a rigid and waterproof coat, which is fine until there is structural movement and the finish cracks allowing the ingress of moisture via capillary action through these fissures. Movement and thermal cracks can be minimised by applying a layer of expanded metal or plastic lathe to the substrate prior to rendering, but this is often omitted on cost grounds.

The characteristic of cement renders to maintain a waterproof layer tends to work against it when it cracks as moisture ingress becomes trapped behind it keeping the structural elements damp and making them prone to degradation either through being continually damp or the freeze, thaw action of frost. From an environmental perspective a damp wall also has a greater ability to transmit heat through it thus reducing its insulating properties.

Ultimately a cement based render will become 'blown' and drop off a structure and if constructed in a soft material taking a chunk of substrate with it. Lime render will deteriate with age and erode away from a building but leave the basic substrate intact. As lime is a relatively soft material patch repairs can easily be carried out.

 

Restoration of Lime Rendered Finish to Monastery Court, Elm Hill, Norwich

Photographs depict renovation of a gable wall adjacent to the River Wensum. Works involved infilling of large wholes and deformations within wall followed by a three coat lime render to provide a flat surface to which a three coat burnt sienna pigmented lime wash was added to produce the desired finihed colour.

 

Overview of workface

Rough finish prior to render application

View of rough brickwork to be rendered and stainless steel stop bead at corner of wall

Eroded brickwork and lime pointing to be coverd by render

 

Finished wall with burnt sienna lime wash. Grey finish below is a cement render from a previous construction that the client just required a patch repair on

Finished wall complete with lead flashing at top to provide weather protection

Overview from across the River Wensum

 

Lime Rendering

Resurspec Structural Repair Specialists Norwich Norfolk Thor Helical Remedial

This website uses cookies. Find out about cookies here. By continuing to browse this site you are agreeing to our use of cookies.Remove Cookie Message button  Designtec Web Design