LIME POINTING FOR LISTED BUILDINGS
Staffordshire, Shropshire, Cheshire and Derbyshire
David Rudge Associates specialise in lime pointing on a range of historical, period, and listed buildings throughout Staffordshire and the UK. We also provide specialist lime pointing advice and maintenance.
The original lime mortars used in traditional buildings have had a large range of variations throughout the years, meaning that each building requires specialist research to find the most suitable process and form of repair.
There should never be projects that replace lime mortar with modern cement mortars as it can permanently damage the building's structure. A building can be completely transformed by lime pointing and rendering for a renovated conventional aesthetic.
Lime mortar is a vital component in the original construction methods of many historic buildings. To properly repair damaged or missing mortar, the replacement mortar must not be harder or stronger than the original material used.
This is to ensure the natural movement of the building remains the same as before repairs took place. Using a harder or stronger material than what was originally used can affect the required flexibility due to the material's thermal conditions.
Grade II Listed Building Lime Pointing
Grade II listed buildings may be old family homes, chapels, children's homes, or farmhouses. We should protect our heritage sites as they represent historical and architectural significance on a national scale.
Before any changes or work is done on a listed building, the owner must have Listed Building Consent (LBC). If there is no Listed Building Consent beforehand, the property owner and workforce are subject to criminal offence and can be fined, imprisoned, and forced to undo the work.
It is equally important to hire contractors that are experienced in conservation because they will be prepared to deal with the regulations of renovating a heritage site. It is wise to remember to conform to any specifications provided by the local council and the listed property rules.
It would then be advised to speak with your listed building consultant for any lime pointing sample panels. Depending on the contractor you trust for this project, these panels can show variations of aggregates, colours, and finishes that are available.
For example, for some projects, you may want to use subtly coloured sand to promote the colour of a building's stonework.
Only when they are approved by your consultant and abide by the listed building regulations should work on the building be done.
Allow your building to breathe. Lime pointing is a breathable application that you can find in the bedding between stones or bricks on chimneys, fireplaces, doorframes, and walls.
Lime mortars are sometimes described as 'self-healing' because they offer the flexibility of allowing moisture within the walls to leave.
On the other hand, hard-setting cement traps water. On most occasions, using hydraulic lime mortar when pointing can chemically re-seal hairline cracks.
You may want to renovate, restore, or convert a grade II listed building by re-pointing or installing new lime pointing work.
Using lime mortar keeps buildings healthy and prevents further deterioration of the building's original stonework.
A massive plus of lime pointing work is that the resulting finish looks as if it was completed during construction. A lime-based mortar applies a restoration of natural aesthetic by accentuating the building's stonework.
When working on grade II listed buildings, it is important to check the original point work first. There is likely to be evidence of lime decay, such as draughts or damp walls.
If there is dampness, then you have a health hazard. Lime decay gradually happens in external mortars or mortars at an elevated level over time. Decay is caused by weathering, where the dissolution of salt affects the brickwork and allows water to enter.
Ensuring that the drainage system is connected to the building will lead to its successful conservation for many more years to come. Constructing a new land drainage system provides the perfect solution to a building inflicted with dampness.
Alongside re-pointing and rendering, excavating trench around the base of all external walls and then backfilling them with stone aids with proper drainage. An external drainage trench prevents water on the ground from reaching said walls. The drainage pipes must then be installed to lead water to a suitably distanced area from the house where it can safely soak.
If the mortar or stone needs repair or filling in, it may be a necessary precaution to install support beams against the stonework to keep the masonry team safe.
Once the wall is solid and secure, applying mortar and pointing will become easier.
When making the mortar, we source local aggregates that also match the colour of the original mortar.
Firstly, any original mortar, cement, or lime-based pointing applications will need to be considerately removed using hand tools or a rake.
Using small hand tools and not power tools minimises the disruption to the fabric of the building.
We recommend raking the joints a maximum of three times to reach a depth where the new lime mortar will better adhere.
Then, using a plastic mixer, mix the lime mortar that has been created using local aggregates. Next, re-point the wall with the mortar.
The mortar must be heavily packed; otherwise, it will struggle to properly stick to the bedding and fall out. Re-pointing is the renewal of the pointing or joints between bricks.
Once the mortar becomes stiff, leave an open texture finish by beating the wall with a churn brush on the lime point work.
This is the traditional way of finishing any stone, brick, and point work. It helps evaporate any moisture within the mortar and reveals the aggregate particles for a classic aesthetic.
Depending on how much vegetation may have grown over a failed mortar application, we venture to remove as much as possible without damaging or affecting the stonework itself.
Pointing and Renders
Pointing is filling in the joints of masonry or brickwork with mortar to improve how weatherproof a building's walls are.
Render is the application of the first plaster coat to a brick or concrete surface. A building's character can be highlighted when pointing and rendering are done well.
Correctly pointing and rendering is also important to visually match the building's original colour and texture.
If the colour of the mortar used does not match the original, otherwise, the masonry can be damaged, and the aesthetic ruined. However, using lighter mortar than the original can successfully brighten a building and make it look fresh.
Likewise, using a lighter natural lime and sand mortar promotes any natural stone features a building may have on its exterior.
Before any rendering work, any cement-based applications and cladding will need to be removed. As a rule of thumb, applying a 3-coat lime render will provide the ideal level of protection from the elements, while allowing for a permeable application.
Sometimes the first coat can contain horsehair for adhesion, stabilisation, and to level out the substrate if it is uneven.
Once this layer has firmed slightly, the surface must then undergo a scratching process for the sequential two coats to adhere. These last coats of lime render are applied to create a flat surface.
Each layer should be given adequate time to dry.
You should not re-render with a weatherproof or cement-based coating as it will cause more problems than solve them.
Replacing traditional mortar in period buildings with cement mortar causes fractures, moisture entering the walls, and accelerates decay. The water inside a wall can drain out if it is made from a hydraulic lime mortar.
We offer lime pointing for listed buildings and historical buildings. For more information please don't hesitate to get in touch 01889 504219.
We work throughout Staffordshire, Shropshire, Cheshire, Derbyshire and beyond.