Category Archives: Plastering Materials

The future of the skim finish

Knauf Airless1Skimming is looking more and more like a dying art these days.  New builds, both residential and commercial are using a board and tape system with a thin coat of spray machine applied plaster, instead of traditionally plastered walls for speed and cost reasons.  In Europe, the call for skimming has all but disappeared with this system having been adopted years before it became widespread in the UK.  When the board and tape system is not used in Europe, the alternative is a sand and cement compound that is then floated smooth and can be decorated more quickly than a traditional plaster finish.

The board and tape system is more environmentally friendly than the traditional gypsum plaster method, as much of the board is made from recycled material and there is no wasted skim to contend with.  Naturally occurring gypsum is a finite resource, and although synthetic gypsum is available there is a movement towards fully synthetic polymer wall finishes, that are less harmful to the environment to produce and have less waste, being generally used in the newer spray systems that naturally cut down the amount of product used.

While the bare plasterboard finish may be used in residential new build developments, with the finish and decoration left up to the buyers, this approach is not often used by developers who are building or refurbishing a commercial property, as they intend to fully finish the interior before the building is pressed into use.  In these instances, the boards are plastered with a sprayed on ready mixed plaster that can be applied very quickly and easily, requiring only minimal smoothing after application.  Knauf airless seems to be the most popular system among plasterers who have tried it, with a lot of interest from those who have not yet experienced an airless plaster machine.

The superior finish achieved by the Knauf airless system looks like it has been decorated once it is dry, so for retail and office spaces there can be a significant cost saving on secondary decoration if a clean white finish is desired.  It is also ready to paint a lot more quickly than a plaster wall, so saves even more time on a whole job.  This is great news for people who plaster and decorate, as the job as a whole will take less time and be more profitable, especially because you can charge more for spray plastering than manual plastering.

Of course, the board work has to be perfect if the airless spray plastering system is to work properly, as it cannot even out differences between the boards – it is only a very thin coat after all.  There may be more time spent ensuring that the boarding is perfect before spray plastering can begin, but even with that extra time investment the system as a whole is quicker than traditional plastering, and quicker than manually evening out gaps and then skimming over slightly uneven boards.

As the machines are still quite expensive (and there are training costs on top) the cost to the customer is higher than a traditional plaster finish, but the high-end clients are looking for the latest technologies and the most consistently good finish, meaning there is good money to be made at the top end of the market.  As the price of the machines come down and it is more widely used, it will be open to those on a lower budget too and will become more popular as a choice of wall finish.  The airless spray plaster, which comes ready mixed, is fully breathable, so it can be used on old properties, as well as new.  This is a real game changer for the restoration market and new builds alike.

The downsides to airless sprayed plaster is that it is not as hard wearing as a traditional finish, and repairs are more intrusive with a machine than when it is being done manually.  There will always be a market for traditional skimmed plaster, but the airless spray system is muscling its way onto the scene.  Even if you just attend a training day for now, and leave the investment for the future, it is a good idea to get with the times and see what this new technology can do, because the likelihood is that you will need to use it at some point.

Acoustic plaster options

acoustic plasterboardOn large residential and commercial projects sound travel and acoustics are very important.  In a large open plan family home with small children there will be a lot of noise, and parents do not want this to travel all through the house.  Similarly, restaurants and other public spaces do not want echoes and sound reverberation to disturb their diners and customers, so space planning and the choice of wall covering is an important factor in reducing echoes, sound travel and unwanted noise.  Large expanses of glass, stone or exposed brickwork that is included in a building plan for aesthetic reasons exacerbates the problem of noise reverberation and travel, so it is even more important that the sound is controlled in another way.

Acoustic plaster and soundproof plasterboard are both good ways of dealing with this problem and the choice between the two methods comes down to cost and the space that needs treating.  Spaces with curves and unusual wall heights are more suited to the acoustic spray applied plaster option, as there is no need to cut boards down or struggle to achieve a smooth curve from individual pieces of soundproof plasterboard.  More standard rooms, like reading rooms in libraries or in a normal domestic house are suitable for the board system.  It is important though, when using a soundproof plasterboard, that the plaster layer used on top is acoustically transparent, otherwise the only effect will be soundproofing that room from the rest of the building and the internal acoustics can still be undesirable.

Acoustic plaster and complete plastering systems are available from many manufacturers, and some are comprised of a double layer system with a substrate bonded coating that absorbs sound and a plaster coating that allows sound waves through to the absorbent layer.  Armourcoat is a new system to the UK, and was launched in March across the country.  It uses a mineral wool layer applied directly to the substrate, with a surface coating of marble based plaster which allows sound to penetrate to the absorbent mineral wool beneath.  The marble plaster coating can be coloured to reduce the need for further decoration as it leaves a smooth and desirable finish.  In testing the 30mm system achieved a class C rating for airborne sound absorption, and the 50mm system achieved a class A rating.

Stil-Acoustics offer a slightly different system with only one layer of coating needed.  The acoustic plaster is either sprayed directly to the substrate in a variety of finishes (Acospray) or supplied as plasterboard (Acoplaster).  As with the Armourcoat system it is available in different colours, and achieves a class A rating at 35mm thickness.

Other manufacturers of acoustic plaster systems are Fellert, Terraco and Quietstone, although not all these manufacturers make wall coverings – Quietstone is an acoustic ceiling solution rather than one that can be applied to walls as well.  These types of acoustic plaster systems are ideally suited to addressing problems with sound levels in spaces such as offices and restaurants, that may have large expanses of glass or tiles and very little vertical wall space that can be treated with an acoustic plaster.

The big benefit to using an acoustic plaster system is that a free-flowing space can be designed with no need for clever baffles and sails to redirect and absorb unwanted noise.  On new builds especially, you may find that the architect has specified the use of one of these systems in order to be able to keep a very open plan main space that does not have to be engineered around sound issues as a primary concern.  They are also ideal for use in a space that has acoustic issues but where it is not appropriate to redesign the flow of the space to install soundproofing features.  Most of these systems are spray applied by machine, which is yet another good reason to get into machine plastering, as you will be able to offer these soundproofing and noise reducing plasters alongside the standard range of surface finishes.

Carrying and fitting board – could it be easier?

roughneck-plasterboard-carrier1Carrying plasterboard can be torture on your back and fingers, not to mention that lifting plasterboard (and anything else that comes in large sheets, such as kitchen worktops, wardrobe panels and doors) is intrinsically heavy and hard work.  It is especially hard work when carrying a lot of items back and forth, up a steep driveway or similar tricky terrain.  If there are two people to carry each board it is a lot easier, but sometimes working alone is unavoidable so something that helps with heavy and unwieldy plasterboard is a lifesaver for solo workers.

The Roughneck plasterboard carrier is the answer to these problems.  It is cheap and lightweight but will hold up to the job for years and save you money on painkillers and osteopath appointments.  Made from plastic it may appear flimsy on paper, but can carry a load of up to 80 kilos.  It is deep enough to carry all but the thickest insulating plasterboard with ease.

For an apprentice who is still building up their muscles, this product will help them get the job done safely and quickly without wearing them out, meaning the trained staff can get on with their jobs and not have to help out a labourer or apprentice with the carrying or teaching various techniques for shifting plasterboard.  This plasterboard carrier is also ideal for anyone moving house or carrying out large scale renovations where kitchen surfaces and doors are being replaced or moved around.

When hanging doors or fixing plasterboard in a solo effort, a board and door lifter is another valuable tool that will save time and energy.  It slides under the bottom of the board or door, holding it in position while it is fixed.  It is much more adaptable than using odds and ends of wood or chisels and screwdrivers to keep things in position and can be adjusted with a foot with no danger of it slipping away, as there is with a screwdriver.

When to speed up, when to slow down

young-plastering-apprenticePlaster and render mixes are designed to have the optimum working and set time, allowing each layer to be applied and finished before starting to dry in readiness for the next layer or the final set.  These times are usually ideal for working with, but there are some occasions when you need extra time to finish a set, or you need it to go off a bit quicker.  The size of the area, the weather, and the skill level of the plasterer can all affect the timings; and in these cases you can use additives to slow down or speed up the drying times of the product to suit.

In the summer, plaster and render retarders are useful for keeping the mix workable, when the extra heat and humidity causes it to set more quickly than it should.  Extratime plaster retarder allows between thirty minutes and one hour extra time to complete and set.  This is good for ceilings and large walls that would otherwise be a challenge when hot weather sets finishing plaster too quickly.  It works by slowing down the crystal formation that sets gypsum plaster solid and comes in sachets portioned for a single bag.

Silomix retarder is designed for bricklaying and plastering mortars, and while the average plasterer won’t have much call for bricklaying products, the additive would be useful for anyone working on buildings with very uneven walls to plaster.  By having a slower set time on levelling mortar a better, smoother finish can be achieved that will be suitable for the finishing plaster to be applied to.  The product gives up to 24 hours retardation, which means that on large uneven walls a very level finish can be created over the space of several hours, taking the pressure off the plasterer.

Evermix 3 in 1 is a render additive that waterproofs, plasticizes and increases setting times for external wall coverings.  It is useful for large outside areas that are being finished in hot weather, as it ensures the render dries slowly enough to adhere to the wall properly and will not crack or blow soon after drying.  The extra properties aid in the slower drying and superior finish of the finished wall surface.

Plaster retarders are also useful for amateur plasterers who are working on an area larger than they are used to.  The extra time allows for some reworking of each coat or application over a large surface area, which may pose a challenge for the inexperienced plasterer.  Getting the hang of plaster setting times is incredibly useful for novice plasterers who intend to make a career of it; so apprentices and those in training, may find it more appropriate not to use retarders when starting out, saving them for when they have a better intuitive feel for setting times but need a little extra help when the weather is warm.

In the winter plaster and render accelerators are more useful, as the mix will dry more slowly than in the summer anyway.  They are especially useful for external rendering, as it is imperative that any application of render to a wall in the winter will have to stand up to the worst of the weather, which can not only affect the drying times but the integrity of the surface as well.  Many accelerators also act as a frost proofer, stopping the water in the mix from freezing and causing cracks when it fully dries.

GoRend Speed Up is a new accelerator on the market which allows two coats of render to be applied and set in the same day, removing the problem of low overnight temperatures affecting the setting.  By using a product like this there is no need to worry about protecting a setting surface overnight with sacking and tarpaulin.  Like Extratime, it comes pre-packaged in the right amounts for one standard bag of render.  It works at temperatures above freezing, so will not work well when temperatures are persistently below zero degrees.

When the ambient temperature is very low, Everbuild’s frostproofer and accelerator is your best bet, as it works in sub-zero temperatures.  This is a liquid product so requires accurate measurement for it to work properly but it will protect against frost damage while the mix sets, and speeds up the setting and drying times in very cold weather as well as in normal conditions, when a more rapid set is needed.

Baumit Speedtop is an accelerator designed for silicone and acrylic renders rather than cement and gypsum based ones.  It is also a liquid product bottled in the right amounts for 25kg of render and also works to speed up setting times when humidity is high; it works in conditions up to 95% humidity.

As with retarding products, these accelerators can be difficult for novice plasterers to use, as the setting times change dramatically from the norm.  While a retarding product simply slows the set times down, an accelerator speeds it up significantly, and if the person applying the plaster is not quick enough it can set far too soon, leaving unfinished layers that need to be removed before starting again.  Before using one of these products it is a good idea to get feedback from other plasterers in your area, who are dealing with the same climatic issues, and if possible wait until the weather is warmer to do the job without the challenges of cold and rain.

Mapei EWI Systems and Energy Efficiency

External wall insulation manufacturers, Mapei EWI Systems have over 80 years of Bright sunlight streaming into a living room interior with a parquet floorexperience of manufacturing chemical and adhesive products for the construction industry. Their award-winning products are available in a wide range of finishes and offer a variety of different insulations for a broad variety of properties.

Fully compliant with both UK and EC legislation including Green Deal, ECO, DECC, Ofgem and PAS2030, EWI can reduce heating and maintenance costs. Once EWI is applied, the amount of reduction in heating costs is jaw dropping – a whopping 40%!!! It’s no doubt something that the Energy Saving Trust put into consideration when they decided to award them certification for their very durable and clever external wall insulation system, .

The positive news doesn’t stop there either. The good thing about applying EWI is that not only does it make your house warmer in the winter, but it makes it cooler in the summer. Overall, your living environment is improved. You don’t even need to move out whilst it’s being applied as all the work will take place externally.

In addition to enhancing the aesthetics of any home, it can protect the fabric of the building. The good news is, is that it may even increase the value of your property.

Something that we really appreciate about the Mapei EWI Systems team is that they are exceedingly helpful too. If we have any questions, we just pick up the phone to them and they can help quide us if necessary. You don’t even have to ask us to do it for you, once you’re a customer of ours, they will be more than happy to help you directly.

As with many of our other products, we offer next day delivery on the Mapei range of external wall insulation products. Either give us a call or drop us a line and we will be able to confirm delivery to you once you’ve placed your order.

Plastering Goes Further Than the UK

Although there are some truly outstanding examples of ornate plasterwork to be found in sri mariamman hindu temple, chinatown - the UK, it’s obviously not just here that they exist. Let’s head over to Singapore for the fascinating ‘Rojak’ style.

‘Rojak’ means ‘mixture’ in the language of Malay. It is sometimes used as the name of a salad or fruit salad that is comprised of a mixture of additions. When applied to plastering in Singapore, it can refer to the ornate plaster work that is applied to the façade of a building.

For example, running through the centre of Singapore, sits Balestier Road and a fascinating building. Although the external wall of this building may not have plaster as we know it, using the familiar gypsum, it has rendering that has been worked on to produce locally important figures that are raised from the wall.

A mixture (‘rojak’) of symbols such as monkeys, cherubs and pineapples are on the walls. At the entrance, there are two guards who stand to symbolise protection of the building. Look closer and you’ll see a collection of other animals including bats, dragons and peacocks.

Although to visitors to the country, it may look to be just a random mixture of animals, it’s actually a collection of important symbols that represent the different races of peoples that have migrated to Singapore.

The peacocks represent the valued virtues of Hindu culture, compassion and patience. They also represent the Chinese cultural values of peace and beauty.

The unusual external plasterwork is expensive and a display of wealth in Singapore. It has been created in the unique Straits Baroque style. Unfortunately, the location of the shop, which is on a busy road, means that the passing cars and pedestrians don’t see the beauty as they are in a hurry to reach their destination.

Considered to be a heritage building in the local area, it has been featured films. It is located close to the local film studios and would most likely be recognised by many as a landmark building.

Plastering is used all over the world in different ways. If you know of an interesting building, send us pics and we’ll share them with our followers.