PVCu vs Steel: Choosing the right plaster bead material

Selecting the correct, high quality plaster bead will ensure a neat, crisp, long lasting professional finish, every time. Here's why it's so important.

Plaster bead might be viewed by some as a commodity purchase and as such insufficient care may be taken to select the right product for the job. Yet, using a material that is unsuitable may shorten the life of the plaster or render and present serious issues for the condition of the property.

One of the most important factors to consider when choosing plaster bead is the location of the plaster or render and conditions that will be present. This will decide what type of bead should be used and will have a significant impact on whether or not the installation will perform and last as expected. Broadly speaking there are three main materials for plaster bead; galvanised steel, stainless steel and PVCu

Given the difference in strength between PVCu and steel materials, choosing between the two of them can be a bit of a challenge. By comparing the two, we can outline some initial considerations to be made:

Types of steel plaster bead

There are two main types of steel plaster bead: Galvanised, and stainless. Here's how they differ:

Galvanised steel plaster bead

Galvanised steel bead is designed to be used for internal plasterwork. The zinc coating protects the steel from corrosion but is generally unsuitable for exterior areas. A number of different galvanised products are available to suit the specific application. Our Catnic range includes angle, depth gauge, movement, architrave and plasterstop bead, as well as products for drywall and thin coat plaster.

Stainless steel plaster bead

The corrosion resistance of stainless steel makes it suitable for exterior applications and interior areas of higher moisture. In particular stainless steel bead should be used where a cement-based render is being applied.

Here at Catnic, there are standard angle and renderstop bead available alongside plasterstop and movement bead for different widths and plaster depths.

Now that we know the types of steel plaster bead available, let's examine where steel plaster bead excels.

High impact resistance

Due to the high tensile strength of steel, steel plaster bead has a much higher resistance to impacts, especially compared to plastic beading.

Overall strength

Another benefit of its high tensile strength, steel is known for its overall durability in permanent wall installations, with steel plaster beading being able to last much longer when correctly handled and maintained.

High rigidity

Steel is a naturally rigid material, allowing installers to consistently achieve straight lines with their plastering work.

Manufactured from polyvinylchloride unplasticised (PVCu), these bead should be selected for projects situated in the most aggressive climatic conditions. BS EN 13914-1:2005, which covers the design, preparation and application of external rendering and internal plastering, advises the use of stainless steel and PVCu in conditions of high humidity and/or salt-laden atmospheres.

Not to be outdone by steel, PVCu plaster bead carries its own advantages:

Corrosion resistance

Plastic plaster bead does not corrode - it is therefore a great choice for external use where the chance of exposure to moisture is increased.

Weight

Plastic bead is much lighter than metal bead, which makes them a lot easier to transport from place to place. Their light weight also means that PVCu bead are easier to install – a great benefit for DIY fans.

Versatility

The Catnic PVCu beading range features products suitable for a variety of applications including twin nose angle bead designed for two-coat renders. The first nose acts as a gauge for a scratch coat and the second provides a depth guide for the finishing coat.

We've covered steel and plastic plaster bead, so now let's cover the decisions and considerations you should make when making your final choice.

Product quality

When choosing plaster bead, the quality of the product is crucial to achieve a neat, professional finish and to ensure longevity of the plaster or render. When selecting a metal bead, a product manufactured from a heavier gauge of steel is always recommended.

The stronger, more rigid bead will help deliver a true straight edge and a precision finish. A strong, straight bead is also faster and easier to install with less wastage. Catnic’s galvanised bead are manufactured to a gauge 11% above the requirements of both British and European standards, while its stainless steel bead exceed these requirements by 25%.

Weather resistance

Similarly, with PVCu bead, not all products will perform at the same level. As with our steel bead, Catnic’s high quality PVCu products have been engineered to meet the needs of professional plasterers.

The range is exterior grade UV resistant and features a unique Pro-Grip™ adhesion system. The tiny grooves manufactured into the face of the bead, ribs and undercut perforations increase the surface area, creating a stronger bond with the plaster or render. This speeds up application and prevents the slippage often associated with traditional PVCu bead.

CE markings

It is also always advisable to check that the plaster bead has a CE marking. This indicates the manufacturer has declared conformity with all safety, health and environmental protection requirements to achieve that CE marking.

Make your next project your best, with Catnic. We manufacture both PVCu and steel plaster bead for use in a wide range of conditions.

With a history of over 50 years and our products used throughout the UK and worldwide in thousands of installations, your project is in safe hands with Catnic.