Ceiling skirting boards: how to cut corners?

Any renovation work is always completed with finishing. In rare cases, the interior of the room does without a ceiling plinth, its presence helps to hide the joints of the finishing materials used for wall and ceiling surfaces, in addition, do not forget about the decorative function that this element carries. It is not difficult to arrange the perimeter of the room by simply fixing it in a straight line. It is much more difficult to cut it correctly in the corners without spoiling the material and spending a minimum of time and money..


The ceiling plinth, like any other element of the interior, has its own characteristics, therefore, before purchasing it in a hardware store, you need to understand the materials from which this element is made and what difficulties you will have to face during the work.

Previously, the ceiling plinth had a different name – fillet. Translated from German means “notch” or “groove”. The material for the manufacture of this decorative element was gypsum, which was poured into a prepared mold. The cured gypsum element was fixed to the ceiling surface with mortar. Today, gypsum ceiling plinth is very rare, its cost is high, and it is much more difficult to install it in comparison with modern counterparts..

Ceiling elements are now available in several types of materials in numerous configurations. They are cheaper than gypsum ones, but they look no worse. The cheapest copies are made from polyvinyl chloride (PVC). This material is subject to deformation with insignificant mechanical stress, the formation of irreparable dents or creases leads to a complete replacement of the element. In addition, all manufactured PVC skirting boards are electrostatic, dust accumulates very quickly on them..

Ceiling skirting boards made of polyurethane and polystyrene are among the most demanded products. They gained their popularity due to their reasonable price, a wide range of profile patterns, a variety of sizes (their width varies within 5–250 mm), as well as resistance to moisture. Polyurethane ceiling elements can be found in the design of many rooms, they look great in any interior. But, there are also disadvantages, the material does not tolerate temperature changes, is prone to cracking, especially if installed above a stove.

The classic version of the ceiling plinth is a wood product. Wooden elements, unlike the listed types, are not installed on glue; self-tapping screws are used to fix them. Plinths made of this material are used to decorate wooden houses or rooms, whose style is dictated by the use of wooden elements..

Required tools

Installing a skirting board means trimming the excess length and adjusting it in the corners. In order to do a pruning, you need tools. The choice of this or that type of tool depends on the material from which the plinth is made..

When working with wood and plastic, use an electric miter saw. Cutting with this tool is accurate, fast and effortless, you just need to set the required parameters and correctly lay the skirting board. It will not be difficult to choose the appropriate tool, since manufacturers produce this tool in a wide price range.

But, with wood and plastic, you can cope with another well-known carpentry tool – a miter box paired with a hacksaw. This tool is in the form of a tray, made either from wood, or from plastic, or from metal. In the two parallel sidewalls of the miter box, there are saw slots for easy cutting of the plinth at the desired angle. In a simple tool modification, the ceiling element can be cut at an angle of 45 or 90 degrees, and in a more complex version, the plinth can be cut at an angle of 60 degrees..

A miter box and a hacksaw are cheaper than a miter saw, but they also have their drawback – this is the risk of damage to the material, especially if the quality of the purchased material is poor. In addition, the miter box is more suitable for rooms with smooth walls and corners..

For a smoother cut without the risk of damage to the material and without delamination of the structure, a jigsaw is suitable. It is easy to operate this tool, with its help you can set any direction and make the most accurate cuts. For materials lighter in weight and with a less strong structure, you can use an ordinary construction knife, the main thing is to pick up a specimen with a sharp blade.

How to cut?

There are two main questions facing the installation of a ceiling plinth. How to properly cut a skirting board without gaps and with perfect fit in the corners, and what tools should you use to get a beautifully positioned ceiling element in the end? In order to understand these issues, it is necessary to study all the methods and tools used in trimming the skirting board. Almost all methods and tools can be used to adjust the skirting board in both internal and external corners..

Outside corner

For the outer corner, the skirting board is trimmed at an angle of 45 degrees. First you need to check the evenness of the outer corner. If the wall surfaces are in contact with each other at exactly 90 degrees, you can use a miter box to trim the skirting board. In order to properly cut the outer corner planks, it is necessary to correctly position both parts of the skirting board..

First, you need to outline the length of both halves, and only then trim them at an angle of 45 degrees. In order not to change the position of the saw and not to get confused with the location of the halves of the plinth, it is necessary to correctly position them in the miter box. The left half is laid face up, with the part adjacent to the ceiling closer to the center, and the second side adjacent to the wall should be pressed against the slotted sidewall. With the right half, everything is different: it must be laid face down in the miter box, and the location of the adjacent parts to the ceiling and wall here will be the same..

The bar placed in the miter box for a smooth cut must be pressed against the sidewall, placing it as close as possible to the slot. Holding the workpiece with your left hand, you need to carefully make a cut and put it aside. The second half of the skirting board should be cut in the same way, remembering to turn it face down.

In the absence of a miter box, you can make a draft of it on paper or cardboard. First, we draw a rectangle, inside which on the longer sides we draw two more parallel lines. On each side, inside the lines, using a protractor, set the desired angle in different directions. Preparation and subsequent cutting of workpieces is exactly the same as using the tool itself.

This method is good in that you can postpone the angle not strictly 45 or 90 degrees, but a little more or less, because the surfaces of the walls in the corners are not always directed towards each other at an angle of 90 degrees, there are errors. Therefore, for a more accurate cut on the miter box depicted on paper, you can draw any angle using a protractor. The degree of the angle is first checked using a protractor, the resulting value is divided by 2. The resulting number will be the exact degree for the correct undercut.

If you wish, you can make a miter box with your own hands. The easiest way is to make a tool out of wood, you just need to take three planks and put together them in the shape of the letter P. Then make marks on the side parts at different degrees, use a hacksaw to make slots. You can also make a miter box from two planks, having previously made slots in them, or use a drawing with the desired angles on paper to accurately determine the slope.

You can even use a table as an improvised tool. The main thing is that he has angles along which he could navigate..

In order to properly cut the outer corners, you can do without any auxiliary tools and drawings on paper at all, you just need to design the future corner in place.

The skirting board of the outer corner always protrudes into the room by an amount equal to its width, therefore, to determine the exact cut, it is necessary to make marks on the right and left halves of the skirting board. You need to set aside the width from the side adjacent to the wall. Then, from the resulting point, lead a line to the upper corner of the half. The resulting triangle must be cut out, and the halves must be joined in place for a preview..


The same methods and tools can be used to join the halves of the skirting board in the inner corner. The location of the halves in the miter box when cutting for the inner corner is identical to the location of the parts used for joining the outer corner. But, you do not need to turn the right half of the plinth for a cut, but only change the slope of the cut (use a different cut). In any case, on the left side of the skirting board, the line will be sloped to the left of the corner point located on the side adjacent to the wall, and on the right side of the skirting board, the line will be sloped to the right of the similarly located point.

For perfectly flat corner surfaces, you can use a regular square instead of a miter box. To do this, you need to press half of the baseboard to the inner corner of the ruler and cut off the unnecessary part at an angle of 45 degrees. This is not difficult to do, since the side of the ruler and part of the plinth form a total of 90 degrees, the notch line divides this angle in half, which means that part of the plinth will be cut at an angle of 45 degrees.

For wooden and plastic skirting boards, it is not possible to make an incision in place, you can only apply a marking on the surface of the skirting board, and then cut the cut along the mark using a hacksaw or a saw.

In order to properly cut and then join the halves of the baseboard for the inner corner, you need to measure in place with a simple pencil. The right workpiece must be applied to the corner from the corresponding side until it stops. Draw a line on the ceiling surface along the half and remove the workpiece to the side. We do the same with the other half..

At the intersection of the two lines, a point has formed with which you need to make marks on each half of the skirting board. To put a point, you need to attach a half to the docking place. From the resulting point, you need to draw a line to the bottom corner of the half, as a result, you get a small triangle, which you need to cut off.

The halves cut in this way must be adjusted to each other, with inaccurately cut edges, the cuts can be leveled with a knife if the material of manufacture is foam.

To eliminate minor blemishes on the cut of wooden or polyurethane skirting boards, you will have to use a file. Only after complete coincidence of the cuts can you start fixing the halves.

Sometimes you can’t get a perfect fit, but there is always a way out.. To eliminate cracks, you can use a putty. The choice of filler depends on the baseboard material. In order to eliminate inaccuracies in trimming the skirting boards, you need to practice using small pieces of the skirting board or cut the planks slightly longer than the intended size. Such a margin will make it possible to make a new undercut in case it was made with the wrong slope or the material at the cut point was deformed.


For a good fit of the ceiling plinth, it is not enough to properly cut and join the halves, you also need to glue them correctly. In order not to later cover up the cracks in the corners or alter the work altogether, you need to adhere to certain recommendations.

  • Before the final installation of the skirting board, it is necessary to properly prepare the surfaces that will come into contact with it. Priming or simply treating parts of the ceiling and wall surfaces will help improve the adhesion between the skirting board and the surfaces..
  • The corners of the room in which the skirting boards are installed should be decorated first. The remaining sections of the perimeter are mounted only after the complete installation of the corner elements.

If there are not only internal, but also external corners in the room, the priority is in the design at the internal corners, since there is a risk of making a mistake with the length of the plinth.

  • In order to fix the ceiling element without gaps, it is necessary to press the plinth quite tightly to both surfaces. It is worth remembering that excessive pressure on some materials can lead to deformation of the element..
  • To avoid getting glue residues on the front surface of the element, you should immediately remove the excess adhesive before it has time to dry..
  • Sealing joints and cracks with a sealant should be carried out only after the glue has completely dried. Compositions with acrylic are most suitable as a sealant..

As an alternative to the time-consuming sawing method, you can opt for the lighter version for cutting corners. Today in hardware stores you can see ready-made corner elements for sale. There is no need to cut the skirting boards at the desired slope, you just need to adjust them in length and then connect them. The finished corner just needs to be glued at the junction of the two halves, and all defects will be hidden. This is very convenient when there is no time to fit or the material of the skirting board is too heavy to work with..

For information on how to cut the ceiling plinth, see the next video..

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