Non-porous cement based render causing dampness in a grade II listed barn in Darrington, Pontefract

Should I Remove Cement-Based Render?

When it comes to removing non-porous cement-based render, there are a few things to consider. One is the historic value of the render. If the render is part of the original fabric of the building, then it may be worth keeping for historical reasons. Another thing to consider is the condition of the render. If the render is in good condition and is not causing any problems like dampness inside your building, then there may be no need to remove it straight away. However, if the render is in poor condition and is beginning to cause damage to the underlying Masonry, then it would be best to remove it. Ultimately, the decision of whether or not to keep the render on your building should be made on a case-by-case basis.

Render is a material used to cover external walls it is composed of cement, sand and sometimes lime. there are modern render systems available but only lime-based renders should be applied to a traditional home. It is applied to walls in a wet state and then left to dry. Once dry, it becomes hard and provides a smooth surface. Render can be removed from brick and stone walls using many different methods, depending on the application of the render. If working on listed buildings, generally hand tools are the advised method and other times power tools are required with skilled operators to ensure very minimal damage occurs.

The most common way to remove non-porous cement-based render from brickwork or stone masonry is by chiselling it off the wall. This can be done by using a few different tools, such as a cold chisel, Club hammer, bolster chisel or electric rotary hammer drill. Another way to remove render is by sandblasting or soda blasting. This method is generally used for large areas that are pasted thinly onto the masonry. However, it can also damage the underlying brickwork. As such, it is important to consult with a professional before attempting to sandblast cement-based renderings off a wall. Finally, the remaining parts of the render can be removed using Thermatech or doff which are superheated steam cleaners, this type of cleaning method is preferred in the heritage industry.

Non-Porous Cement-Based Renders

Cement-based renders were introduced in the late 19th century and became widely used due to their low cost and easy availability. However, these non-porous renders trap moisture behind them, causing damp patches to appear internally and leading to masonry decay and structural instability. The removal of cement-based render can also be a complex and time-consuming process, often uncovering hidden damage that requires extensive repair work. In addition, nonporous renders are often very difficult to remove without causing extensive damage to the underlying masonry. For these reasons, it is advisable to use a professional mason so minimal damage is caused and any issues can be addressed correctly.

Peeling or flaking paintwork is not only unsightly, but it can also be a sign of dampness within the walls of a building. Dampness can lead to erosion, which in turn can damage the structure of a building. In some cases, dampness can also pose a health and safety risk. If you suspect that your property may be suffering from dampness, it is important to have it assessed by somebody who understands traditional buildings. If dampness is found to be present, one possible remedy is to remove the non-porous render and gypsum plaster from your walls. This will help to improve air circulation and allow the walls to dry out faster.

Non-porous renders and pebble-dashed walls have been a big concern for surveyors and conservationists for many years. They cause major health and safety issues, especially when applied to porous masonry in public areas. The cement-based render causes moisture to get trapped between it and the wall this causes dampness and masonry erosion which then causes the render to pull freely away from the wall. It is then only a matter of time before pieces start to fall. The longer non-porous materials are left on walls or chimney stacks, the more damage and risk of injury they can cause. If you have nonporous renders on your building and can see cracking, it is advised to undertake repairs as soon as possible. Surveys show that most buildings with this type of damage are in a poor state of repair and pose a serious risk to public safety.

Removing Pebbledash

The mention of the word “pebbledash” is enough to make any conservationist cringe. The term is inextricably associated with the very worst excesses of the ‘home improvement industry. and, as such, its use is largely confined to council estates and post-war housing developments. However, there was a time when pebbledash was considered a stylish and desirable finish for all types of building, from grand country houses to modest terraced homes. Indeed, for much of the 19th and early 20th centuries, pebbledash was one of the most popular cladding materials in the UK.

Pebble dash, also known as roughcast, is a type of exterior wall finish made by throwing pebbles or gravel at a wet cement-based mortar that is applied to the walls. It was commonly used in the past as it was a cheap and easy way to finish a building. However, pebbledash can cause dampness and erosion, damage buildings, and be a health and safety hazard. As a result, many experts now recommend removing pebbledash from buildings. While it may be a bit of a messy and time-consuming job, taking off pebbledash can help to improve the look of a building and prevent further damage.

The main problem with pebbledash is its non-permeability. This means that it does not allow moisture to pass through it, which can lead to dampness appearing inside your building and decay to the masonry behind it. Pebble dash is also quite rigid, so it can be difficult to remove from walls without causing damage. In some cases, it may be necessary to cut decompression lines into the pebbledash to help with its removal. After the pebbledash has been removed, there will usually be some repair work needed on the masonry and at a very minimum localised lime pointing will be needed.

Lime Render

This is a traditional building material that has been used in the UK since the Romans invaded England. It was used to protect buildings in exposed areas and also to decorate the exterior of buildings. Made from lime and sand, lime render is highly breathable, allowing moisture to escape from the underlying masonry, Moisture is drawn out by air circulating the external walls. This helps to prevent dampness and rot, which can occur when water is trapped behind modern renders made from cement or synthetic materials. Lime render is also flexible, meaning that it can accommodate movement in the underlying structure without cracking. This makes it ideal for use on historic buildings, which often settle over time. In addition, lime render can be tinted or pigmented to create a wide range of different finishes, making it a versatile material that can be used to achieve a variety of different looks. For all these reasons, lime render is an ideal choice for anyone looking to restore or preserve a historic building,

A lime-rendered building is a beautiful sight. The structure rises, its curved lines and simple design a testament to a bygone era. And yet, despite its age, the building looks as though it could have been built yesterday. This is because lime render is highly durable and requires very little maintenance. If you are lucky enough to own a lime-rendered building, all you need to do to keep it in good condition is to lime wash it every 10 years or when showing signs of wear.

Lime Harling

Hurled, or cast-on, finish consisting of slaked lime and coarse aggregate mortar, and it usually has a rough-textured surface. It is the most common type of traditional surface finish found in Scotland on masonry buildings of solid wall construction. The finish provides a key role in the durability of the building by allowing the masonry to breathe and deflecting weathering forces such as wind-driven rain. It also has an aesthetic value, providing a warm tone and texture that is unique to Scottish architecture. Lime harling is generally applied to buildings of traditional construction, where the stone or brickwork is left exposed on the exterior walls. The method of application differs depending on the size and type of building but typically involves either hurling the lime mortar onto the surface from a short distance or building out by hand using a hawk and trowel it is then finished with the harl. Once applied, the mortar is left to dry and harden, providing a protective coating that will last for many years.

Lime harling gives a rough cast finish that is extremely porous due to the open pores when finished. It is without a doubt the best finish for buildings in highly exposed areas. The lime particles act as capillary channels allowing the wind to draw moisture out over a larger area. The porosity of the finish allows any moisture that does penetrate the surface to be drawn back out quickly, preventing it from causing any dampness or corrosion beneath it. For these reasons, lime harling has been used for centuries as a way to protect buildings from the elements, and it remains an effective option today

Lime Washing

Used for centuries as a way to decorate and protect buildings from the elements. The traditional recipe calls for quicklime, which is applied while hot. This allows the limewash to penetrate the render and harling, creating a barrier against weathering. At the same time, limewash also allows moisture to be drawn out of the building through capillary action. This prevents the build-up of dampness, which can lead to structural damage. In addition to its practical benefits, limewash also gives buildings a fresh, clean appearance. For this reason, it remains a popular choice among those who wish to protect their homes and improve their curb appeal.

The Romans used lime for a variety of purposes, including painting walls and ceilings. Lime was also used to whitewash buildings, which helped to reflect heat and keep rooms cool in the summer months. The Victorians also made use of lime paint, particularly in cellars and other damp areas. By painting walls with limewash, they were able to regulate moisture levels and prevent mould from forming. Today, limewash is still used in many historic buildings as a way to preserve them.

Render removal Grange Farm Darrington Grade II Listed building in Pontefract