10 Expert Plastering Tips for a Better Finish

Expert plastering advice from Plastercore

Tip 1: Always Prepare the Surface Properly

A quality plastering job starts before the plaster is mixed.
One of the most important steps in plastering is preparing the surface correctly. Dust, loose material, grease and flaking paint can prevent plaster from bonding properly, potentially leading to cracks, bubbling or delamination.
Before plastering, remove loose material, clean the surface and repair any significant defects. Depending on the background, a suitable primer or bonding agent may be required.

Plastercore tip: Never underestimate preparation. Taking the time to prepare a wall properly can make a significant difference to the finished result and its durability.

Tip 2: Choose the Right Primer for the Wall

Not every wall needs the same preparation.

Different backgrounds absorb moisture at different rates. For example, old brickwork and porous plaster can absorb water quickly, while smooth concrete may provide a poor mechanical key for plaster.

Using the correct preparation product helps control suction or improve adhesion, depending on the surface.

Always follow the plaster and primer manufacturer’s instructions. Applying the wrong product can cause bonding problems rather than solve them.

Plastercore tip: Identify the background before choosing a primer. The correct preparation depends on the material, its condition and the plastering system being used.

Tip 3: Don’t Apply Plaster Too Thickly

Getting the plaster thickness right helps prevent problems later.

Applying finishing plaster too thickly can make it difficult to achieve a smooth surface and may extend drying times. Excessive thickness can also increase the risk of defects.

Where walls are significantly uneven, the surface may need to be levelled with an appropriate backing plaster before the finishing coat is applied.

Always follow the recommended thickness for the plaster product.

Plastercore tip: A smooth finish begins with a suitable background. Correcting major unevenness before skimming is often better than trying to hide it with finishing plaster.

Tip 4: Know When to Use Bonding Plaster

Bonding plaster is useful for certain backgrounds, but it isn’t suitable for every wall.

Bonding plaster can be used as a backing plaster on appropriate backgrounds, particularly where the surface is relatively smooth or has low suction.

However, the background must be suitable for the product, properly prepared and free from conditions that could compromise adhesion.
It is also important to distinguish between bonding plaster and an adhesive or bonding agent. They are different products with different purposes.

Plastercore tip: If you’re renovating an older property, assess the existing wall construction before choosing a plaster system.

Tip 5: Use Scrim Tape to Help Prevent Cracks

Reinforcing plasterboard joints can reduce the risk of cracking.

Cracks can develop where plasterboard sheets meet, particularly if joints haven’t been reinforced correctly or the boards move.

Suitable joint tape, such as scrim tape, helps reinforce these areas when used as part of the correct plastering system.
However, tape alone cannot prevent every crack. Loose boards, structural movement and poorly supported joints must also be addressed.

Plastercore tip: Check that plasterboard is securely fixed and that joints are properly prepared before applying the finishing coat.

Tip 6: Don’t Rush the Plastering Process

Timing is essential when achieving a smooth finish.

Finishing plaster needs to be worked at the correct stage. If you begin trowelling too early, the surface may become difficult to control. Leave it too late, and the plaster may become too stiff to finish effectively.

Temperature, ventilation, suction and the plaster product all affect setting times.

Plastercore tip: Learn to recognise the different stages of the plaster setting process. Good timing is one of the key differences between an average finish and a professional one.

Tip 7: Avoid Overworking the Plaster

More trowelling doesn’t always mean a better finish.

Repeatedly working the surface at the wrong stage can create marks, drag material across the wall or damage the finish.

The aim is to flatten and close the surface progressively as the plaster firms up, using appropriate pressure and clean tools.

Plastercore tip: Work methodically and use the correct trowel technique. Trying to correct every small mark immediately can make the final result worse.

Tip 8: Allow Plaster to Dry Before Painting

Fresh plaster needs to dry properly before decoration.

New plaster often changes from dark pink or brownish tones to a much lighter, more uniform colour as it dries. However, colour alone isn’t always a reliable indication that the plaster is ready for painting.

Drying time depends on the thickness, background, temperature, ventilation and moisture levels.

Once the plaster is sufficiently dry, follow the paint manufacturer’s instructions for priming or applying a suitable first coat.

Plastercore tip: Avoid sealing damp plaster beneath an unsuitable paint finish. Doing so can contribute to poor adhesion, uneven decoration and other problems.

Tip 9: Don’t Ignore Small Cracks

Small cracks can be harmless, but some need investigating.

Fine cracks can develop as materials dry or through minor movement. However, wider cracks, recurring cracks or those accompanied by bulging walls and sticking doors may indicate a more significant issue.

Before repairing a crack, establish what caused it. Filling and painting over a recurring problem may only provide a temporary improvement.

Plastercore tip: If cracks keep returning, investigate the underlying cause rather than repeatedly patching the same area.

Tip 10: Know When a Wall Needs More Than Skimming

Skimming isn’t the answer to every damaged wall.

Skimming can refresh a suitable existing surface, but it won’t solve every underlying problem.

Walls with blown plaster, loose material, persistent dampness or significant unevenness may require additional preparation or a different repair system.

Applying a new finishing coat over an unsuitable background can lead to further failure.

Plastercore tip: A proper assessment helps determine whether a wall needs patch repairs, reboarding, backing plaster, skimming or investigation of an underlying defect.

Need professional plastering in Wirral, Wallasey or Liverpool?

Plastercore provides plastering services for homeowners looking to achieve smooth, durable walls and ceilings.

Whether you’re renovating a single room or undertaking a larger property refurbishment, professional preparation and workmanship can make all the difference.

Contact Plastercore to discuss your plastering project