Laths and lime plasters are a traditional building technique used to construct interior walls and ceilings. Lath and plaster construction is especially common in older buildings. But what makes these materials so special?

In this blog, we will show everything you need to know about laths and lime plasters. Whilst addressing other relevant questions.

Limebase is an ardent supporter of the effort to repair and conserve historic buildings. We supply materials and our extensive range of products to tradesman, DIY builders, architects, and more. Whether you are repairing a historic building, or making creations with lime mortar, we are here to help.

Our range of services are here to help you get the best results for your project, with the least amount of hassle, at the best prices. Explore our extensive product range today!

What does lath and lime plaster do?

Laths and lime plaster are used in conjunction in order to create a durable and long-lasting wall surface or ceiling surface. It was an extremely common building practice before the invention of plaster-board. As a result, almost all older buildings will feature lath and plaster walls and ceilings.

Walls and ceilings constructed with traditional lath and plaster will produce a beautiful finish that is highly breathable, durable and flexible. So let us break down the individual components themselves, laths and lime plaster.

What is lath and lime plaster?

  • Laths are an assortment of thin strips of wood. They are usually nailed horizontally to a wall or ceiling. The laths are usually around 25mm wide and 6mm thick. There is usually around a 6-8mm gap between each lath to allow the lime plaster to push through and form a kind of hook. Laths can be made from hard or softwood, although hardwood is usually recommended for ceilings.
  • Lime plaster is a traditional form of plaster that uses lime putty as a base. It is mixed with sand and in some cases, other additives. Unlike modern plaster (gypsum) lime plaster is a breathable and flexible plaster.

How is lime plaster applied?

Lime plaster is applied over and between the nailed on laths. The lime plaster is applied in multiple layers starting with a haired (horse hair) or plastic fibre lime plaster. This is followed by a non-haired lime plaster, with a final skim coat to provide the best finish. This is known as “3 coat lime plaster work” and is the gold standard. Laths are fantastic for creating dividing walls and ceilings as they provide a strong mechanical key for the lime plaster to attach onto.

Everything you need to know about laths and lime plasters

Everything you need to know about laths and lime plasters

Firstly, if you are unsure if you need laths or lime plaster, consult with a professional first to understand if laths and lime plaster is appropriate for the job you have in mind. With that being said, here is some important additional information about laths and lime plasters.

Does lime plaster help against damp?

Yes, lime plaster can help to prevent damp. Lime plaster is highly breathable, it allows moisture within the building to travel to its surface where it can harmlessly evaporate away. Other building materials such as cement and gypsum trap this water, causing damage over time.

That being said, waterproof alternatives should be considered where water will have direct contact with the plaster, for example, inside a shower.  In older buildings, using lath and lime plaster is ideal.

Is lath and lime plaster expensive?

Although the prices for lath and lime plaster may be competitive, because it is a more labour-intensive process, there is a likelihood that it can be expensive when all the costs have been accrued.

Can anyone apply lath and lime plaster?

Applying lath and lime plaster can be a difficult and time intensive task. If you feel unsure, seeking the services of an expert lime plasterer would be your best bet. Having said that, if you want to do it yourself, there are a number of fantastic videos on YouTube showing the process.

Does lath and lime paster need maintenance?

Proper lath and lime plaster work will require very little maintenance. However, this is subject to the level of application, and the environmental conditions of the area it is in.

For the most relevant advice, be sure to ask the person applying the lath and lime plaster the specific maintenance requirements you should undertake. For now, here are some general pointers.

General maintenance

Under normal conditions, lath and lime plaster requires minimal maintenance efforts. Because it is naturally breathable, it can help to provide moisture build up. Every so often using a damp cloth can usually be enough. The most you will probably have to do is give it a fresh coat of limewash or other breathable paint every so often. 

Minor repairs

Hairline cracks and minor surface imperfections may appear over time, however, they can typically be addressed with a simple patching compound made specifically for lime plaster. In cases of small cracks, repointing with lime crack filler may be enough.

Professional restoration

In instances of larger cracks appearing, damaged sections, water damage or suspected structural movement, contacting a professional plasterer is recommended. They will be able to correctly assess the extent of the damage and recommend the relevant repairs. This can include replacing sections of lath, and or re-applying layers of lime plaster.

What you should remember with lath and lime plaster

With lath and lime plaster, there are three factors that will always contribute to its need for maintenance, they are:
  • The environment can accelerate the need for repairs, this is especially true if the lime plaster is exposed to moisture and extreme temperatures constantly. Harsh chemicals can also contribute to this.
  • The final factor is settlement or movement cracks. The more settlement a building experiences, the more likely settlement cracks can appear. Usually, they are not a major concern, but may require attention from time to time.

Is it better to use lath and lime plaster alternatives?

Some would argue that the speed and affordability of lath and lime plaster alternatives are enough for them to be a better option. However, there is wisdom in the old ways of lath and lime plaster. Hence, why it was commonplace for centuries.

Below are the drawbacks of today’s modern alternatives.

  • Moisture trapping is a key issue with most modern alternatives, drywall being a prime example. Because of its lack of breathability, moisture gets trapped behind the plaster. Over time, this moisture can cause severe damage. This is especially true for old buildings that were originally constructed with lime material’s. In almost all cases, these old buildings must be repaired with breathable materials.
  • A reduction of flexibility is a common characteristic of modern plasters. Because they are more rigid, they generally aren’t suitable for older buildings that settle or move slightly. Meaning cracks will appear easily.
  • When it comes to aesthetics, lime plaster is incredibly versatile. It can be used to create a textured surface, or finished completely smooth. This gives you the option of a traditional textured look, or a more modern smooth look. Of course this character is not possible with modern alternatives.
  • In some instances, modern plasters can have a shorter lifespan, meaning repairs and replacements may be required sooner, whereas lime plaster can last longer. Most lime plaster you will come across will be hundreds of years old!

Order lath and lime plaster today

Limebase is undoubtedly one of the first and trusted names you should think of when it comes to laths, lime Plasters, lime Mortar, and much more. When it comes to our range of products and services, we guarantee excellence.

With over 30 years of experience in the area of using lime, Limebase invites you to get in contact with us if you have any queries or issues you think we can help with. 

Address:

Walronds Park

Isle Brewers

Taunton

TA3 6QP

Telephone:

01460 281921

Email:

[email protected]