No matter how good your plaster, in certain situations it needs a helping hand.
Being made of small grains or particles, plasters and renders have quite a low tensile strength, and their liquid state on application means that they can’t keep themselves up without something to hold onto.
This isn’t a problem in small areas or when applying to a heavily-textured surface, but for an entire wall or areas where forces are applied, such as ceilings or floors, you need to provide some structural integrity.
This is where plaster mesh comes in.
Just as a house needs a framework and your body needs its skeleton, plaster and render need a structure to keep them strong. Plaster mesh is the simple solution, but has multiple benefits:
- It gives your plasterwork something to bond onto
- It offers structural integrity
- It protects against cracking or even, with certain types of mesh, allows for movement
By applying mesh to your floor, wall or ceiling first, you create a far more complete surface, the render and mesh working together to create a durable layer that will last well and resist wear, impact and movement.
Though there are a number of options, plaster mesh can basically be broken down into four types:
- METAL MESH
Whether woven – such as chicken wire – welded wire or expanded (a single sheet of metal cut into an expanded lattice), metal mesh is the toughest option, so best used in the toughest situations. Commercial and industrial rendering or flooring all benefit from this strong, stiff mesh. Stapled to the foundation wall, the mesh gives a tough grid for your render to lock into. It is a bit harder to work with and you also need to be aware of potential moisture, as some types can rust or oxidise, creating staining that will seep through your render.
- FIBREGLASS MESH
In many ways, this is the most versatile form of mesh. It can be used internally or externally, it is flexible, it won’t rust and discolour your render and it provides a solid barrier against pests and even mildew. It doesn’t have the increased strength of metal mesh and can be a little tricky to work with – gloves are essential – but fibreglass mesh is a good all-rounder.
- PLASTIC MESH
Plastic mesh is particularly good when you want a smooth finish over an interior surface. Much finer and lighter than metal mesh, it works well for feature walls and alongside an acrylic render, offering flexibility and excellent resilience to cracking. It also provides some integrity to the entire surface, spreading the weight of wall hangings, hooks and artwork. Though by no means failsafe for this purpose, it is much stronger than plaster alone.
- MESH TAPE
Mesh tape is most often an adhesive woven fibreglass tape. Though it can also be used for crack resistance around structural joints, its most handy use is in repairs. Small cracks and holes can be plastered over, but larger areas need some structure. Where other forms of mesh would be fiddly and require embedding into the surrounding render, mesh tape can simply be stuck across the damage and plastered onto.
So the next time you’re rendering, make sure you get meshy!