basics about plastering

Uni-Kal: Dries faster, hard to work with, a hard surface plaster. Has to be mixed with water. Better if used for small projects/repairs.
Diamond: Takes longer to dry, softer plaster, easier to work with, needs to be mixed with water.
Quality of Uni-Kal vs Diamond product is about the same.
Excalibur: Falls between Uni-Kal and Diamond. The surface is harder than Diamond but softer than Uni-Kal. Also mixes with water.
Joint Compound: Prepared plaster mix. It already has the appropriate consistency to apply without having to mix anything to it. You will need to wait longer for it to dry though, anywhere between 1-3 days to be on the safe side, especially if you will be painting over where you repaired. Joint compound is ideal for small cracks and holes – much less messy, although you may need to lightly sand your finish in a couple of days (which will then cause some white dust), so beware.
Easy Sand 90, 45, 20: Used like joint compound but needs to be mixed with water. The number shown indicates the amount of time (in minutes) for the mix to dry.
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Note: You can use an Accelerator to make the plaster dry faster and you can use a Retarder for the opposite route - to slow down the drying of the plaster to give you more time to work with it before it dries like a rock!

The first step is the full demolition of the walls and ceilings or cutting out the damaged plaster with an appropriate sharp knife. Make sure not to just cut out the exact area of the damaged plaster but give an extra 2 inches around it and in a squared shape as much as possible so that it is easier to hang the new blueboard. If insulation against the cold/hot weather is desired, the insulation is placed inside the walls at this point. This can also help to muffle sounds, but will not make the room sound proof.

Plaster walls and ceilings can get destroyed as a courtesy of a hurried plumber or electrician who does not care since they are not the ones patching the holes. Warning: Cutting through plaster is a messy job with the white dust and possible crumbling pieces. In a clean bucket with cool tap water, you will mix the plaster product, to the consistency of natural peanut butter. The plastering powder or mix to use will depend on the amount of time you need to get the finish done. You can get a basic idea reading this short list on the different types of plaster mixes.

To make a room sound proof, there are many steps to be accomplished. Besides having sound-proof, or close to sound-proof windows and doors, there are specific products that can be used to sound proof a room. After the framing is set up, either wood framing or steel framing, sound proof insulation is one product that can be used and it can reduce noise by approximately 70%. This certainly helps with noise reduction and would be the cheapest way to go about it. Besides reducing noise, let’s not forget that the insulation will help keep the room warmer in cold weather saving you money with heating and less hot in the Summer months saving you money in energy by not having your AC working so hard.

In addition, to make a room more sound-proof, there are sound proof boards that can be used/installed to make the room quieter. Also called Absorbing Acoustic Panels, they are much more costly than just regular blueboard/drywall. However, sure worth it depending on what you are trying to achieve.
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QuietRock Sheetrock is a specialized product for sound proofing, which is known to reduce noise by about 80%, however, if the noise you are trying to block is impact noise (people walking for example), resilient channel and acoustic clip in addition to the QuietRock should be used. The material can be very costly. The work is certainly more laborious and heavy.

Begin by hanging the 1/2 finished drywall, wallboard, blueboard, sheetrock, or plasterboard on the walls and ceilings. Some cities may only have 5/8 or double 5/8 boards for the ceiling. If there are any apartments above, you must screw the plasterboard on the ceiling with at least 5 to 6 screws in each strip. Only 4 to 5 screws per strip are necessary for the walls. Hang the drywall or plasterboard on the ceiling first, and then the walls after. That will make plastering over the cracks on angles easier. When hanging the drywall or plasterboard on the walls, be sure to cut the whole drywall over the doors and windows. Using small pieces can cause cracks in the future. Tape the drywall or plasterboard joints starting with the flat parts of the board. Then place the two pieces together and tape them at an angle.

It is not an easy task, but the end result is worth the effort. The first step is the demolition of the walls and ceilings. The wood work is generally strong steel, and does not need to be disturbed. If insulation against the weather is desired, the insulation is placed inside the walls at this point. This can also help to muffle sounds, but will not make the room sound proof. We will discuss sound proofing with other projects at a later time if desired.

Use the base coat plaster product to plaster the walls and ceilings joints, and then wait until the base coat plaster dries. The optimum wait time is approximately 12 hours. However, waiting that long is not essential. You may begin plastering between 40 to 90 minutes, as soon as the base coat plaster hardens. During the final plaster coat, the veneer plaster should not be mixed more then 1 bag ½ per plasterer. It will dry fast and can be very hard to work with. A professional plasterer will need some time to complete the skim coating with one smooth coat finish.

The veneer plaster work does not have to be sanded before painting!