Lime Render

When working with lime render on historic and in particular listed structures, repairs should ideally be carried out using similar materials to the original. Not only are they more appropriate to the historic character of the architecture, but they usually work better than modern alternatives, especially when used in conjunction with other traditional materials and construction techniques.
Hair is sometimes added into render mixes in order to give them tensile strength. It is important that the hair should bond and grip well in the mix. Horse hair, which appears in some specifications, is unsuitable because it has very smooth edges, and can often be pulled out of the mix after it has set. Cattle and goat hair tend to have rough and barbed edges and grip the render better.
Casein (Milk), eggs, linseed oil, fresh blood, bees wax, tallow, beer, manure and urine have all been used as additives to improve render performance at one time or another. Animal fats and oils improve the water-repellent properties of the render, while beer and urine act as air entrainers.
Below are properties where such techniques have been employed to preserve the characteristics and charm of the buildings.
This fine period property below is located in the Aylesbury area is a grade II listed building from the Regency Period. Over the years various attempts had been made to patch and repair the render, the majority of the repairs were undertaken in cement render and large sections had become damaged due to freeze thaw effect. The original cornice had been patched and touched up many times subsequently it had lost its fine definition. After much research and careful consideration the owners of this property reached the decision to completely renovate the exterior rendering, a well thought out plan.
The entire surface was stripped (and in part by the owners own participation and 'elbowgrease'! ).
Wall2Wall Solutions heritage experienced lime plasterers carried out the application of this three coat "plumb and dot" work to class one standards. The cornice had to be restored with multi coat hair, modified run in-situ mould work (the mould is an exact copy of the original and was manufactured in house ) The final finish of NHL through coloured render was 'Ashlar' struck to create a stone pattern

Click on any image to see an enlarged version

       
Before ^^
       

        

^^ After

   
Works starts on the chimney stacks by applying the base coat

    
Every attention to detail is made, even recessing the lead flashing

       
This cornice had to be completely reformed in situ

       

       
Moulds were manufactured in house from the original forms to match the existing.

       
 Stage Development Work

       


For older buildings with soft brick/stone and/or a high level of dampness we can also undertake traditional hydraulic lime render finishes where the final finish can be self coloured and chosen from a large selection of beautiful, natural colours.

 The use of lime requires a high level of skill and knowledge. For more information on the benefits of lime render please visit our suppliers and for those of you who are looking into the possibilities of traditional lime finishes this is the best site to visit http://www.stastier.co.uk it supplies a large range of very high quality lime material.

           

This is what happens to a damp wall that has the incorrect mix of cement render. As you can see the hard cement render has detached itself from the brick work and has caused some 'spalling'.
If the cement content is too strong it can cause damage to masonry, in effect it's like a cement straight jacket

           

To avoid descending damp the tops of the wall are also treated with a 'capping'

       

As well as rendering the two main houses at the new Leeds Development
Wall2Wall were asked to provide a specification for the specialist rendering of the block garden walls.
Special consideration had to be given for the landscaped garden walls in respect of damp water retention (for the backing soil) Breathability and protection against cracking caused by shrinkage.
It was decided that a NHL lime would best suit this block work with nylon mesh reinforcement scrim PVCu arch beads were incorporated and two layers of Thermocromex were used to sculpture the walls.


                              

This was and is a huge project, heavy restoration work was needed to the cornices, the last 2 images clearly show the deterioration, the bottom are the results of our restoration. Good for another few hundred years.