The classic method of finishing off masonry walls, and one still preferred by many plasterers, wet plastering entails using either a cement-based render or a gypsum backing which is trowelled right onto your bricks or blocks.At first, a scratch coat is applied, known as a ‘key’ coat. This forms the base coat that is gently scratched whilst the plaster remains wet to form a good key for the following layer of plaster — the ‘skim’ coat — to adhere to.
In addition to cement-based and gypsum plasters, lime and clay plasters are favoured by many traditionalists and people needing a wall that will breathe. Lime and clay plasterer devon are more expensive than ‘conventional’ wall surface finishes and it is a good idea to only use a plasterer with know-how of such materials.
One thing to note though: if you are going to be applying the approach of wet plaster on an outside wall, do do not forget that you are not able to add insulation as you can with plasterboard — except in cases where you are happy to utilize external insulation on your home. So, if you have solid brick walls — instead of cavity walls — you should consider the effect that a paucity of insulation could have.
Provides an even, hardwearing finish
Suits traditional properties perfectly
Straightforward to apply around challenging areas such as windows and doors
Offers superb airtightness and soundproofing
Can’t add insulation inside behind this kind of plaster
Takes more time to dry out than alternative techniques
Hairline cracking may appear
High skill level is neccessary — a skilled plaster might be difficult to find and will regularly ask for more for this type of work.
Plasterboard with Skim Coat
There are a couple of regular board thicknesses of plasterboard — 9.5mm for 400mm spacings and 12.5mm for 600mm. Additionally, there are several different methods in which plasterboard may be fixed to a wall: ‘dot and dab’ or ‘board on dabs’, and plasterboard that is screwed to timber battens fixed to the wall.
With dot and dab, sheets of plasterboard are adhered to either brickwork or blockwork walls applying dabs of adhesive and allowing merely a small cavity between plasterboard and the wall. With the batten method — perfect for all those wanting to add insulation to a solid wall — timber battens, usually measuring 38mm wide along with a depth to support the thickness of insulation you are using between them, are screwed to the wall.
Rigid board PIR (polyisocyanurate) insulation is then placed between the battens just before the plasterboard is fixed over the top. A vapour control layer is also essential in the case of solid walls.
Lastly, the joints between the boards are lined with scrim tape — commonly in the style of a self-adhesive tape — right before a skim layer of plaster is trowelled on to the plasterboard.
Hairline cracks — which are generally linked with wet plaster — are improbable
Faster drying out time
Possible to carry out on a DIY basis
Insulation can be fitted behind plasterboard
The cavity created can take up room space
Can be difficult to fix shelving, radiators and pictures
Offers little in the way of airtightness
Scrim would not always cover up the space between the sheets of plasterboard which could be evident through the skim coat.
In place of having a skim finish applied to plasterboard, it is entirely possible to use the plasterboard itself as the final finish — in truth, this is typical in the US and in a growing number of developer houses in the UK as well.
In the event of taping and jointing, tapered-edge board is normally selected. Joints are taped and next filled over, as are any screw or nail holes. The whole surface will then be sanded prior to painting. It is quick, comparatively affordable and crack-free.
Quicker and significantly less messy than the other methods
Works out a little cheaper as no plasterer is neccessary
Can be carried out on a DIY basis
The final finish is rougher and a little dull, even if painted
Walls feel hollow when tapped and lack the solid-feel of plastered walls (particularly when used on stud walls)
Plasterboard is easily damaged and difficult to restore