Plaster spraying machines made light work of commercial plastering jobs when they were first developed, and have become the mainstay of any firm specialising in external rendering, new builds or large scale plastering projects such as sports centres, stadiums, schools and office buildings. The speed with which they get the plaster on to the wall saves a lot of labour costs, as a single person can cover an area up to four times the size compared to a manual application in the same time. The surface is then finished by hand around features, but the finish achievable by the most modern spray plaster machines does not need smoothing once applied. It is worth bearing in mind that this finish is not as smooth as a manually finished wall, but passes muster for most commercial projects and is acceptable for plastering walls that are then going to be lined and painted.
Plaster spraying machines can be used on domestic projects, but the amount of preparation that is required to cover all other surfaces and items in the room is considerably more than with conventional trowel plastering. As the plaster is sprayed on it travels a lot further than the trowel could ever send it; there may be fewer instances of plaster falling off the trowel and spots around the bucket, but if the nozzle of a plastering machine ends up facing the wrong way, even once, there will be a lot of mess to clean up. This extra covering and preparation costs money, as you need more sheets, tarps and tape to get everything stuck down properly, but if the homeowner can do this preparatory work it can make sense to get the plastering done quickly and keep costs down for everyone. Domestic new builds are often plastered with a spray machine, as there are no carpets or furniture to protect and multiple surfaces need to be covered; but once the homeowners have moved in there is often too much to protect or move to make spraying worthwhile in single rooms.
Another reason plastering machines are not commonly used on small jobs, is that they perform best when applying first coats and renders, and the cheaper models can struggle to achieve the very smooth surface that most customers associate with a good plastering job. There are time and training costs associated with starting up a machine plastering offering, and sometimes this can be prohibitive for sole traders and small outfits. Larger plastering or building services companies could do well to invest in a plastering machine and the associated training, as it can significantly increase the volume of work that can be achieved by the existing staff, leading to increased profits which will pay for the machine in a matter of months.
Of course, cleaning the machine can take time but it is a good job for an apprentice or casual labourer. There are also maintenance and repair costs to factor in, but a plastering machine cannot be off sick, so while there may be more outlay on maintenance, the reliability of service makes plastering machines a good option for companies with changeable or casual workforces. Of course, single rooms and re-skim work does not call for a plaster spraying machine, but if these jobs make up only a small percentage of your workload and there are many more larger jobs, that can be time consuming when done entirely by hand, plastering machines make commercial sense. The other good thing about plastering machines is the gadget factor, who doesn’t love a new toy every now and then?