Short History. Plastering has been around for past Nine thousand years, we have evidence of this in ancient Anatolia and Syria. But we have a lot more evidence from the last Five thousand years; we now know that the ancient Egyptians used a form of Gypsum plaster that was applied onto reeds. Hair was mixed in and used to give the plaster strength and bind it all together, they heated there gypsum on an open-air fire, then it was crushed It into a powder with water then added to make a working plaster. This was used to plaster inside and outside of their pyramids.
We can still see this today when we look at their paintings on the wall’s of their pyramids. Ancient Egyptians Wall Painting. The Greeks and Romans used Gypsum in the form of a screed, which is lime, gypsum, sand, plus an early form of cement, this was all mixed together into a powder and then water adder for consistency. There was plaster and stucco (plaster was used for interiors, while stucco is used for exterior surfaces) but they manly used gypsum to make their statues. The early form of cement then went on to be the basses of modern concrete. Old Roman Building.
Roman or Greek Statue made from Gypsum. So what is Gypsum? Gypsum is a naturally crystal- rock that can be found all over the world. When it has been quarried it would then be crushed and heated, to remove some or all the water, and then ground into a powder. When water is added to the powder, there is a chemical reaction between the water and the powder and it starts to set rapidly (within 10-20 minutes) and this then becomes a form of Plaster of Paris. A form of this Plaster of Paris is still used to this day to set bones in Hospitals. Dentists take moulds of teeth to make new dentures.
The powder that we use today for plastering has a retarder added, so the setting time is much longer. Dentist use of Gypsum Hospitals use of plaster. From13th century through 19th century plastering gained much importance. Knowing the value of applying plaster to the interior walls and ceilings as well as the exterior surfaces, it protected the wooden structure of the houses of the time from the elements also keeping in the heat plus now having walls that could be decorated. The plaster used at this time was sand, lime with horse hair added to bind it all together for walls and ceilings.
External wall were just a sand and lime mixture, but both internal and external walls took 2 weeks to dry out and harden, but this was only in appropriate conditions it could sometimes take up to 8 week but gypsum plaster had a lot lees drying time but the cost of gypsum was it biggest problem, in the early 20th century plasters started to use gypsum instead of lime, which gave them a better binding with sand, furthermore the setting time was now controlled, allowing the plasterer to layer plaster in a few hours instead of weeks. Average Medievel homes. Tuder Home. Victorian Home. Induction. Plastering may look easy to the untrained eye, but as many people may have tried in their own homes and failed, (would have found out! ) it is an art form all on its own. With plastering you need a lot of practice, so that you could achieve a perfect finish, but even then you will make mistakes, that you will have to overcome. A good plasterer needs to “pay attention to detail, have a good technique and a good understanding” of what they are doing plus knowhow.
After saying all that it would still be possible for a novice to do small jobs and still get good results, however it’s still advisable not to try anything larger than patches, until you have had a lot of practise. Plaster Skimming a Ceiling. Some of my work. First Step. The very first thing that you need to do is assemble all you equipment (tools that you will need). Plastering trowel- hawk-2 to 3 buckets-large mixing bucket- plunger and stick or power drill with paddle- paintbrushes- straights edged- spirit level- and tin snips.
Most of this list you would need with you at all times, but you may not use. One of most important things to remember as a plaster, it is never to start any work before making sure that all you’re (tools are clean! ) Even a tiny piece of old, dried plaster on your trowel or straight edge, can damage the surface of any newly applied plastered wall and all your hard work can then be set back because of this, it would be very hard to put the wall right, plus you may even have to (re-plaster). Rambler to Always Keep your Tools Clean! ) Preparing work and work space. You first will have to put some dust sheets down on the floor or hardboard. So this will mean you will have to clear the room of any furniture, if this is a new build, the room – house will already be empty. If you are going to skim (Plaster) on new plasterboards, you would have to make sure that all screw heads are in fare enough. If not the screw head could take a bad nick out of you trowel, your trowel would have to go on a stone to get the nick out.
Tape all plasterboard joints including ceiling and internal angles; this is to prevent cracking when the plaster has dried “you would not need to tape ceiling angles if the ceiling was not being plastered also if the internal angles if you were only plastering one wall” If you are re-plastering a smooth surface, it should be brushed down to make the wall free from dust, dirt and grease so to help plaster to stick to the wall properly. Mix up some pva (glue) three parts pve to one part water, and brush all the wall “you might have to do this twice” and this will help kill the suction and your wall is now ready for plastering.
Preping your room for Plastering. PVA Wall. to kill suction. Mixing Plaster. Mixing plaster is the most important part, along with applying it, but if you cannot mix the plaster yourself, how can you then tell your work mates how you would like it to be, so you must be sure that you plaster is always consistent. It is important that you plan this stage carefully because once the plaster has been mixed; you only have a limited time to apply it before it becomes unstable and starts to turn. In the summer plaster can turn in minutes so only mix the amount that you intend to use immediately?
Do not add any plaster to an older mix and don’t add water to a mix to try and make it soft and more workable. Mix you plaster according to the instructions on the bag and add the plaster to the water and not the water to the plaster, making sure that the water is cold and clean! Mix your skimming with power mixer or by hand, mix until the skimming comes to a thickish, creamy consistency making sure that there are no lumps, at this stage do not over mix your skimming because this will put too much air into your plaster, which in turn will make it set much faster that you would like.
Make sure that your plaster is not to watery because this will make your skimming weak and intern you plaster will not adder to the walls properly. Mixing paddel. Mixed Skimming . Appling Plaster. Now onto applying of the plaster, there are two coats of skimming to be applied, the first coat is the scratch or base coat this should be around 2mm thick. Now that the plaster in on your board and stand, scrape a trowel of plaster from you board and onto your hawk. Keeping you trowel wrist straight and then using a flicking action with your other hand so you can move half the plaster from you hawk to your trawel.
Working from the top of the wall (if you are right handed you would be working from left to right! And if you were left handed you would work from right to left! ) using a smooth even strock press the plaster onto the wall, gradually closing the angle of your trowel’s edge, as you move your trowel downwards always keep your trowel at a slight angle at the end of every stroke. If you flatton your trowl onto the wall when you lift it off you will remove the plaster with your trowel.
At this stage don’t worry about any line’s or holes that you see in you plaster because this is only the first coat. So in the same way that you applied first coat do exaclly the same with the second coat (or gage) except this time you are trying to make it as smooth as possible. knowing you have to give the wall its first rub, but this all depends on the drying time of your plaster, cut around your wall with your trowel to get rid of all the snouts then with just your trowel give your wall its first rub, right across the top then across the middle and then across the bottom.
Depending on the drying time repeat the last step exactly, this time you would use a little water, you would repeat this one more time, again with water depending on the drying time and this would be your polish. Making sure that you always allow proper drying times between each rub. Plus remembering that you always keep your trowel and tools cleen all the way throughe the procedure.