To majority of the homeowners, there is no killer job such as finishing joints in their premises by use of fiberglass tape. Most will consider it a back-breaking job and a few will take a step of doing it. But it’s actually the simplest job which can be done by one person when finishing a room or two.

It only needs a bit of your time, focus and effort. It’s a form of art when doing finishes on your drywall. To become an expert, it takes years, but with good guidelines, you will manage to do a better job.

Also as houses age with time, cracks on the plaster are bound to occur. But that it’s not very important, what matters is how you going to fix it. Repair may require a few skills but also good repairing materials and tools come in handy. Finding a good repairing material to cover the cracks can be quite a challenge.

And this where the fiberglass tape also comes in as the best option, it requires a little effort in setting it up. In most cases, a single person can handle it best, unless it is a repair of a larger surface area.

Tool and materials need

  • Fiberglass tape
  • Joint compound
  • 100/150 grit sandpaper
  • Tools drywall knife 4”/5”
  • Knife 8” to 12”
  • Corner knife
  • Flooring covering
  • Screw gun or hammer
  • Razor knife


  1. Wall preparation

Wall preparation forms the basis and the vital part of the whole process of using the tape. Moreover, it also affects the finishing after the whole process of taping and application of joint compound is complete. During the preparation step, carefully examine the wall

Check if there are any nail or screw protrusion on the surface. If you get to find any, do all you can to drive them slightly below the surface level. Any protrusion left will have a negative impact during the finishing process at the last stage. The bump will restrict the formation of a smooth finish.

The gaps found between the drywalls need to be filled before the tapping process begins. Filling gaps which are small is fast and with no complications. However, when dealing with large gaps, things get a little intricate. The larger gaps are characterized by slow drying and shrinkage which results in the compound cracking.

You need to clean the wall thoroughly before continuing with the whole process. Sawdust, dust or any other material which is not eliminated will create a lumpy wall. The lumpy wall makes it hard when applying the joint compound. Intense cleaning is not that necessary but the focus should be on the removal of heavy accumulations.

During the application of the joint compound, some may drop on the floor. Avoid the dropped joint compound as they can carry foreign particles which will emerge on your surface during finishes.

  1. Method of applying the tape and joint compound

When you are through with the wall preparations, it’s time to move to the next step, the application of tape and joint compounds on the drywall.

Begin by opening the joint compound, at times you may find a liquid which is on top separated from the rest. Do not pour the fluid; it’s actually part of the joint compound. Moreover, during the compound mixing, follow the instructions carefully in order to attain the proper viscosity.

When dealing with joints, there are three main types which are commonly sealed using the joint compound and tape.

  • Corner joints- this are found where two walls are joining or where the ceiling and the wall joins.
  • Butt joints- in this case, the dry walls cut edges meeting point’s forms these joints.
  • Flat joints- these types have walls with tapered edges and wrappings meeting each other.
  • Flat joints tapping impact- from the name, you would expect a joint which is very flat. But considering the fact that the tapes and joints are fixed on a surface which was initially flat, this guarantees a slight crown on the surface. Therefore, the focus at this point is based on creating the least crown size which is unnoticeable.

To make the crown remain unnoticed, spreading the joint compound on a wide area is the best way to achieve it.

  1. The joint compound art of application

For the best output, the compound has to be applied through following given technique to ensure perfection. Below are the guidelines which will guide you through and they will ensure you master the art of joint compound application.

  • At the start, load your applicator knife with a quarter capacity of the compound which it can support. While holding the knife vertical with respect to the wall, stroke the knife across the wall.
  • As you stroke, gently flatten the knife on the wall in order to provide it with more of the joint compound.
  • When you have applied enough joint compound on your wall, set the knife on the wall at 45 degrees angle. The more vertical the knife is set the lesser the air pockets are created on the joint compound, and subsequently a smoother surface is formed. In addition, more gouges will be formed as a result of small changes and movements in the knife.

If it’s the first time experience working on the joint compound application, then doing some practice on another section of the drywall will be handy. It will enable you to have a good knife control and also know where to apply more or less pressure while applying the joint compound.

Use of proper tools


Size of the knife

The last skim coat

10 to 12”

Block coat

8 to 10”

Taping  and cover of screws or nails

4 to 6”


  1. Tape Application

First layer taping

Start by sticking the fiberglass tape on the joint. Ensure the tape lies at the center of the joint well, since the tape sticky surface is not that strong enough apply the joint compound immediately. In this step, use either a 4” or 5” knife to do a perfect job.

When applying the joint compound ensure it’s pressed enough on the tape for firm adherence. But ensure you are not hard enough on the application of force to the extent of exposing the tape.

The main objective, in this case, will be to feel the mesh holes while at the same time, maintaining it submerged in the joint compound. However, do not apply the excess compound in order to submerge the tape quickly. Apply just enough to cover it completely.

However, you don’t have to worry about the visible patches of the coat. Those patches will be taken care of in the next layer application of the joint compound. Also, it might be very challenging to submerge both the joint corner in a single moment.

This is because, while perfecting the texture on one side of the joint, the other knife end will be scraping off the material on the other side of the wall joint. If it could be possible, you can handle the sides each per day. That means you will be dealing on the other side when one side is dried already.

  1. The time duration between coat applications

When you are through with applying a coat, give it enough time to dry up before proceeding to the next layer of the coat.

The normal room temperature is great for this process, it’s just enough to initiate quick drying of the layers. But when dealing with rooms which have a much lower temperature than that of the room or higher humidity in the air, the time of drying will take a bit longer.

Applying a layer on top of another which has not dried will result in a delayed shrinkage. Also, it will result to crack formation on the surface. This will occur when you add another layer of the joint compound on the previous layer that did not dry well. Therefore, when the inner layer dries fast than the outer layer, it will cause strains between the two layers that will result in crack formations.

  1. Application of the second layer of the joint compound

Before proceeding with the next layer after the first has completely dried, examine the tape first, check for the presence of protrusion, and if any, use sandpaper to scrub off the surface

It’s a common step even though not a commended one to add a pinch of water in the joint compound for thinning. It will make it easy to pull the compound under the knife during application but at the same time creating a few pockets during application.

But this also has limitations, as the compound will lose its adherence power and fall off the wall or knife easily during application. When you are a beginner dealing with a single room or so, it’s commended that you should not thin the joint compound.

The aim of the second layer of joint compound is the elimination of the imperfections made during the creation of the first layer. Also, at the same time, the focus will be on the extension of the applied joint compound width. The treatments of the three different types of joints have different treatments but served with the same type of knives (8” & 10” knives).

Flat joint: this will require a single knife pass during application of the joint compound. Then it will be preceded by one or two layers to smoothen the joint compound.  After you have cleared all the air pockets from the applied joint and cleaning of the edges, you will remain with roughly 10”.

Butt joint: when dealing with this, you will need at least two passes for the joint compound application. Due to the crown formation on the wall as a result of the tape, apply the compound around the crown up to roughly 6”/8” coverage on every direction.

For final smoothening, you will require about two passes of the joint compound which is also preceded by either a single patch or two in the removal of the ridge created and left behind.

Corner joints: if you are a beginner, you will need at least two days to complete this joint. It’s quite a challenge to apply the compound to one side while failing to interfere with the other side. In this case, the corner knife comes in handy during the application of the block coat.

In all the types of joints, the block coat application is maintained thin. When exceeded to even 1/16”, then you will have to apply sanding, and this is most required on the butt joint. Application of the block coat needs precision and neatness for the best result.

This is because, at this point, you are close to the finishing point, and any defects created will appear on the final results. It’s advisable to sand the surface after you are through to attain superior results.

  1. Application of the third joint compound skim coat

When the dry coat is fully dried and you can feel it on your fingertips, then you are ready to proceed to the final layer. This is the only chance you are left with to create a perfect job or remove any defects created earlier. Therefore, utilize it maximally and carefully examine the surface for any flaws. 

Get rid of protrusion and any foreign substances that may have got entangled in your work. In this case, a light sanding of the surface is commended, but it relies mostly on the quality of work you have attained so far.

Over the surfaces of both butt and flat joints, ensure the skim coat has a minimum of 18” broadness. While at the corners, at least one foot on each of the sides, at this stage, all the joints will receive again final pass to eliminate the unavoidable ridges. This stage consumes a lot of time and effort in order to attain a perfect result.

Ensure there are no air pockets formed or even grooves. Once you are through and it’s dry, do sanding on the surface, by either use of sanding paper or a sponge which is a dump. Once you are through with sanding, all you need is paint and your wall is done.


The whole steps of working with fiberglass may consume a good portion of your time. But patience and focus will guarantee you the best results. Follow the steps through each at a time while allowing the resting time intervals for the layers to dry. On the final product, many people go wrong. For instance, sanding too much will destroy the drywall and waste all your effort. To avoid over sanding, use hand sandpaper and avoid machines.