Commonly Asked Questions

About Exterior Plaster Cladding Systems

Do modern plaster cladding systems provide a weatherproof cladding solution?

Are plaster cladding systems installed by trained and qualified tradesmen?

Can plaster be taken below ground?

What are the final texture options?

Can I leave my exterior plaster system unpainted?

Is waterproofing necessary on plastered solid masonry?

Will targeted repairs to your plaster cladding increase the value of your home?

Are targeted repairs to plaster cladding simply delaying the inevitable?

What are the benefits of targeted repairs?

What doesn't a targeted repair approach give you?

Is recladding my only option to obtain a Code Compliance Certificate?


Do modern plaster systems provide a weatherproof cladding system?


We have installed over 1500 new plaster cladding systems since 2006 and have never had a reported leak in any of those installations. Houses must now be constructed using treated timber and all plaster systems over timber frame are now constructed on a cavity and fully flashed. A properly constructed plaster system is at least as weatherproof as a weatherboard cladding system.

We have absolutely no hesitation recommending modern plaster cladding systems. Of course, any exterior cladding installation is only as good as the tradesmen installing the system so you always need to make sure you are dealing with a reputable business that employs qualified tradesmen. 

Are plaster cladding systems installed by trained and qualified tradesmen?

Yes they are.....

Plaster cladding systems are deemed to be restricted building work under the Building Act legislation and should be installed by a Licensed Building Practitioner. In our business, it is mandatory for all our plasterers to be trade qualified and all our team leaders are Licenced Building Practitioners. We have nine Licenced Building Practitioners for Exterior Plaster permanently employed and 23 trade qualified plasterers. Always make sure you are dealing with the right people so you get the right result.

Make sure you ask whether the persons installing your plaster cladding system are qualified tradesmen. It is no point if only the boss is licensed and qualified but he is seldom onsite. Long-term performance and durability of plaster cladding systems rely upon accurate and correct application of the materials.  

What are the different final texture options?

There are many different final texture options for plaster systems. The best way to view the range of options available, is to call into our showroom at 19A Triton Drive, Albany where we have 20 final texture samples on the walls.

Can I leave my exterior plaster unpainted?

Over the past few years, we have had a number of requests from clients to either leave their plaster system unpainted or to apply a clear sealer to waterproof the plaster. On a cement based plaster system, the paint coating is the first line of defence against external moisture. Accordingly, we would never leave a cement based plaster cladding system unpainted. Clear sealers are a poor option because they break down in the sun’s UV rays and require recoating every two years (that is a lot of upkeep, especially if scaffolding is required).

There are acrylic textures specifically designed to replicate the aesthetic look of raw natural plaster such as the Sto MP Natural final texture and we would recommend such an option to a client looking to achieve this type of finish.

Is waterproofing necessary on plastered solid masonry?

Yes it is.

We have been involved in numerous remedial projects involving solid masonry homes and commercial buildings. Typically, the issues arise from a lack of waterproofing around joinery, base levels and deck structures. Whilst solid masonry structure will not rot, interior linings and floor coverings will still get damaged by water leaking into the structure and steel reinforcing could get damaged. 

There are a number of plaster compatible waterproofing products on the market specifically designed for this purpose. We typically use Sto Flexyl waterproofing, Sika Monotop and Sikalastic waterproofing products as they are compatible with exterior plaster systems.

Is it only plaster homes that are leaking?

All types of claddings will leak if poorly designed and constructed.

Many of the major contributing causes of leaky building problems have nothing to do with the plaster cladding system (for example, poorly installed flashings, leaking joinery and leaking waterproofing on decks and gutters). Whether the cladding is weatherboard or plaster, if water is entering the building structure through one of these defects, you will have leaky home problems.

Will targeted repairs increase the value of your home?

Most home buyers are very wary of non-cavity plaster homes (i.e. those built prior to 2004) and will obtain professional advice and inspections prior to purchasing such a home. However, there is no question a poorly maintained cladding system and high moisture readings in the wall structure will be detrimental to the sales process.  

In our experience, the targeted repair approach has helped many of our clients achieve the best sale price they could for their home and shortened the time it took to sell their home (which also means less marketing and holding costs).

That said, a targeted repair approach will not always achieve the best outcome as a number of factors must be considered when determining the best solution for your situation. As a general rule, the higher the potential value of a property, the more likely a full reclad will make better economic sense.                 

Of course, if you take no steps to prevent moisture from entering your home, your building structure will continue to deteriorate and will eventually become uneconomic to repair (i.e. the repair costs become greater than demolishing the home and rebuilding). 

Are targeted repairs to plaster cladding simply delaying the inevitable? 

Yes they are. The whole point of undertaking maintenance work is to extend the useable life of the building. No building material will last forever but proper maintenance and keeping moisture out of buildings will certainly add many years to a buildings useable life.  

We often hear comments that targeted repairs do not actually fix leaky buildings and recladding is the only way to achieve that goal. There is truth to that comment if by fixing a house you mean bringing it up to the current building code requirements.

However, there needs to be some sensibility brought to this discussion as not all homeowners can afford to reclad and for some houses recladding does not make economic sense. Surely, this does not mean that such homeowners should do nothing and let their home deteriorate due to continuing moisture ingress?  

Moisture ingress into the structure of your home must be stopped.

What are the benefits of targeted repairs?

A drier and healthier living environment.
Extending the usable life of the home by preventing and/or significantly reducing future rot and decay.
Massive cost savings compared to the cost of a reclad.
Improved saleability and market value.
Documented repair process to show a prospective purchasers.
History of cladding performance (where an annual monitoring program is undertaken).

What doesn’t a targeted repair approach give you?

Compliance with the current Building Code E2/AS1 (i.e. E2/AS1 requires a cavity and therefore only a reclad will achieve this)
A Code Compliance Certificate from the Council.
A guarantee that all rotten or decayed timber has been removed and replaced with treated timber (this can only be achieved with certainty by removing all the existing cladding).
A guarantee that all defects have been fixed (an on-going monitoring program is required to ascertain the long term performance of the cladding system).
The redundancy of having a cavity installed (i.e. a secondary level of protection against moisture entry).
Re-establishment of full market value. Non-cavity plaster homes are more difficult to sell and attract lower sales prices than non-cavity weatherboard homes due to a negative market perception and stigma associated with leaky homes.

Is recladding my only option to obtain a Code Compliance Certificate?

It depends on many factors relating to the risk of moisture ingress.

If your plaster home has a lot of high risk design and construction details and is already suffering from significant moisture ingress problems, the chance of getting a CCC issued without recladding is low. On the other hand, if your plaster home is relatively low risk and is not yet suffering major damage from moisture ingress, you may be able to achieve a sign-off from Council and obtain your Code Compliance Certificate.

To obtain a CCC, the Council will need to be satisfied that the plaster cladding is performing and this will involve some investigation. Furthermore, the Council will want to be satisfied that the plaster cladding system will continue to perform in the future. Typically, this will require work to reduce the risk of future failure and to build some redundancy into the plaster cladding system. If you are facing this situation and need some advice, give us a call to discuss your particular situation.