How to cut porcelain stoneware tiles at home

porcelain, stoneware, tiles, home

How to Cut Porcelain and Ceramic Floor Tiles. Tile Mountain

Combined disc models

Angle grinder discs for tile cutting got a similar name due to their ability to work both dry and wet. This is an intermediate option between segmented wheels and dry cutters:

  • cuts better than segment, but worse than solid;
  • works continuously more solid, but less dry-cutting.

Jigsaw

The best way to cut floor tiles is to use the electric version of the diamond wire jigsaw. To do this, after laying, fix the tile on a flat surface of a chair or table. In this case, the area with the drawn line on the front side should be suspended. By running the tool along the mowing line, you can get an even cut line without chips.

Work technology

Glass cutter and stationery knife

The main thing when cutting with these tools is accuracy and clarity of movements. You need to act calmly and consistently:

This option is more suitable for cutting thick tiles.

  • use a flat surface of the floor, table or stool;
  • put a tile on it with the front side up, make the necessary marks and draw a line with a ruler and pencil;
  • apply a ruler to the mowing line until it is completely aligned;
  • make a clear cut along the ruler, pressing firmly on the glass cutter;
  • tap along the notch;
  • under the line of the notch, you can put a drill and, gently pressing on the edges, break the tile. If you place the tiles along the cut groove on the edge of the countertop and gently press down, you will also get a good result;
  • with a good cut of the tile, it will break exactly along the mowing line.

You need to cut with a clerical knife using a similar technology. The only difference is that the cuts must be made several times on the same mowing line to deepen the furrow.

Angle grinder

The angle grinder with a disc-shaped cutting element is considered a universal tool for cutting and processing various types of materials. The choice of a device for working with porcelain stoneware is determined by its turnover. Here, high power will have a positive effect only on cutting speed, but not on the quality and accuracy of the resulting edge.

Discs on stone or concrete will break the edge. Therefore, the cutting wheel is considered only diamond-plated. On trading floors, such equipment is presented in two versions:

Solid for wet cutting. Here, cutting is carried out with periodic wetting of the disc with water or a special compound in order to cool it. The main advantage of such a circle is that cutting of porcelain stoneware without chips occurs (it depends on the nature of porcelain stoneware: thickness, texture, quality).

Solid diamond disc

Segment Diamond Blade Source allegroimg.com

Porcelain stoneware is usually cut with a hand-held angle grinder. For her, equipment up to 2 mm thick is relevant. To obtain a better result, consider discs whose cutting edge is wider than the height of the tile being processed. And also before each cutting it is recommended to check the backlash of the nozzle, which should be minimal.

Work begins with marking the front side. The canvas must be placed on a flat solid base, secured. Before cutting the porcelain stoneware in order to minimize the number of chips, first form a starting groove up to 3 mm away from you. When the cutting requirements are low, it is enough to make a cut to a depth of half the height of the tile and break it.

Sawing ceramics with a grinder

For which tile the glass cutter is not suitable?

The use of a glass cutter is justified only for glazed varieties of tiles, the surface of which resembles glass in structure and appearance. Limitations also apply to the thickness of the tile product. its maximum indicators should not exceed 5 mm.

It is impossible to cut mirror tiles with a glass cutter. Its dimensions and installation scheme are selected in such a way that one-piece elements are used.

Gypsum tiles are not recommended for processing. its rough coating will be difficult to cut, crumble and delaminate. Not the best option would be ceramic tiles of a high class of wear resistance (from two or more). These are durable and tough types of materials such as porcelain stoneware and floor tiles.

Stone discs

Sharpening bits are most often made of stone. They constitute a solid base with a minimum thickness of 6 mm. Thanks to their massive base, stone discs are ideal for sharpening tools that conventional fine bits cannot cope with.

As a rule, stone discs are not suitable for tile cutting due to their great thickness. But they can make the tools at hand sharper without much effort. A stone wheel with glued on sandpaper petals is suitable for grinding materials. It is recommended to clean the tiles with a soft abrasive marked 20, 150, 180.

Tile cutting methods

Tiles can be cut in a variety of ways, from a simple glass cutter to a powerful electric tile cutter. Depending on the equipment used, the following types of tile cutting are distinguished:

using a glass cutter. It can be recommended for cutting a small volume of thin tiles, it has an increased percentage of rejects, not suitable for cutting thick tiles;

You can try to cut thin tiles even with a nail 120. 150 mm long. A deep scratch is scratched on the front side, then the tile breaks. But this method can only be used out of despair, when there is not even a glass cutter at hand.

using a manual tile cutter. The principle of cutting does not differ from a glass cutter, but due to the design of the device, thick tiles can also be cut;

using an angle grinder and cut-off wheels for stone work. The advantages include high productivity, but cutting is accompanied by a strong dusting of the room, the edges of the tiles are sloppy, crumble. It can be recommended for outdoor work with a large work front;

using electric tile cutters. The working body of these mechanisms is a diamond wheel rotating at high speed. In addition to high performance, such mechanisms use water to cool the disk and dedust. Due to this, the cut is perfect, requiring no additional processing. But the use of electric tile cutters is justified only with a large amount of work;

in some cases, it is necessary to make a round through hole in the tile. The use of a manual or electric tile cutter is not possible in this case. For this, it is recommended to use a special ballerina drill bit. You can also try to make such a hole with a glass cutter. You can also cut the tiles with a jigsaw.

The choice of cutting tool also depends on the tile itself. A regular glass cutter is also suitable for thin tiles. But cutting thick porcelain stoneware tiles with a glass cutter or a small manual glass cutter will be extremely problematic. For this material, it is recommended to use an angle grinder or an electric tile cutter.

Why does porcelain stoneware crack when cutting with an angle grinder? Disk selection

Generally speaking, you can cut with any circle. The question is different, how to cut with a given level of quality, with minimal difficulty and cost. The first disc that comes to hand can leave too many chips, break tiles or fail quickly. But in case of extreme need and without claims for quality, you can cut it like this.

Advice! For cutting tiles with an angle grinder, it is recommended to use only diamond-coated steel discs with a thickness of 2 mm or more.

Smaller diamond discs are used in machine tools. When used with hand tools, the likelihood of impacts and jerks increases, which leads to damage to the liner, destruction of the disc.

Diamond-coated discs are available in several types:

  • Segmented. The surface of the disc is divided into equal segments. Diamond plated on the cutting edge. In the process of work, thanks to the slots, the disc is partially cooled. Note! Such cooling only increases the period of continuous operation (up to a maximum of 1.5 minutes). Then you need to take the tool back and let the disk cool down (20. 30 seconds at idle speed). The discs are designed for dry cutting;
  • Solid. Full circle with diamond grit applied to the edge. Designed to work with water cooling. It is convenient to use such a disc to process the edge of a cut tile; segmented tiles are not suitable for this. The cut after such a disc turns out to be more accurate. For cooling, you can periodically wet the tiles, use a spray bottle, or cool more often. The speed of work will be noticeably lower;
  • Combined. Universal blades for dry and wet cutting. They lose in terms of cooling segmented, in terms of quality of a cut solid.

Example of diamond cutting discs: segmented, solid, combined.

To reduce chips, it is desirable that the height of the diamond spraying is greater than the thickness of the material that is being cut.

When working, it is important to monitor the condition of the disk. At the slightest damage, the disc changes. Otherwise, working with a defective disc will lead to chips, destruction of tiles or to traumatic destruction of the disc itself. (As a variant of minor defects. the appearance of sparking during cutting. Sparking should not be, sparks mean that the metal base is touched, which means that either diamond dusting is exuded or a metal burr or shavings have formed. You can try to grind the defect on stone, plaster, concrete. If sparking continues. it is recommended to change the disk).

There are a lot of discs of different quality and different purposes. In addition to the types, thickness and height of deposition, the density of the deposition and the size of the deposited diamond particles are important. For cutting tiles with an angle grinder, such details may not have much effect, but when cutting thick floor tiles, dense ceramics, especially porcelain stoneware, the choice of a disc can become critical. In these cases, it is recommended to try several discs on pieces of material and choose the best option.

How to cut 10 mm porcelain stoneware. How to properly cut porcelain stoneware tiles at home

Porcelain stoneware is an excellent finishing material that combines the best qualities of ceramics and natural stone. The material is stronger than granite, wear-resistant and resistant to aggressive environments. The tile is produced by the industry various.

Before you start cutting porcelain stoneware, it is better to first familiarize yourself with its types

  • Technical porcelain stoneware;
  • Glazed;
  • Matte;
  • Polished;
  • Structured or patterned porcelain stoneware;
  • Lapped;
  • Aged;
  • Slim. slim.

You can cut any shapes and configurations from porcelain stoneware tiles at home. Porcelain stoneware tiles are often used in the design of the floor, steps of stairs, porches, walls and plinths of the house. Although the material is very hard, it often leaves unclean chips in place of the cut. Types of cutting porcelain stoneware tiles at home. using an angle grinder with a diamond disc (diamond), tile cutter, glass cutter, jigsaw, waterjet cutting (only industrial cutting on professional equipment).

An angle grinder with a diamond wheel is often the only option for cutting porcelain tiles. But when working with this famous tool, there are some nuances. The fact is that when tiles are cut, this work is associated with the release of a huge amount of harmful dust, an unpleasant burning smell and wild noise. Therefore, when working with an angle grinder, you must protect your eyes with protective goggles, and also wear a respirator.

When cutting tiles, you need to know that the diamond wheel must be kept straight without moving and clearly follow the mowing line, which is held on the back of the tile.

It is necessary to work with the disc carefully, drive the disc along the mowing line, retreating behind the cut line 2-3 mm from the mowing line towards the chips. It is also necessary to press the tool firmly and guide it along the mowing line calmly, with great pressure. If you make a cut in this way, then the cut will be neat, without chips. There is also one more piece of advice when working with porcelain stoneware. The ceramic granite tile must be rigidly fixed, clamped with clamps and screwed to a fixed surface, such as a table. The fact is that this must be done according to safety precautions. after all, when cutting, you must press hard on the tool.

How to cut porcelain stoneware tiles at home.

It is most convenient to cut porcelain stoneware tiles at home with an angle grinder, since it is a universal tool and is available in every home. Special diamond cutting discs are used for stone processing. The thickness of the cutting wheel should be at least 2 mm, and the height of the working edge should be slightly greater than the thickness of the tile.

Any angle grinder will do, but it is more convenient to work with a small device. Power does not matter as it is better to cut at low speed. The tool will cope with tile material of any thickness, it is possible to make both straight and curved cuts. When using an angle grinder, it should be understood that high quality cannot be achieved. Additional sanding is required on the edges. During cutting, a large number of fragments and dust particles are formed, and it is difficult to process a lot of tiles with this unit.

  • marking is applied to the glazed side with a marker;
  • the tile is placed on a flat, level surface (it is recommended to fix it with clamps);
  • carefully make a cut, deepening in 1 pass by no more than 3 mm;
  • they go through the cut several times;
  • the tool should be moved slowly and carefully, there is no need to put additional pressure on it, since the weight of the angle grinder is sufficient;
  • the resulting chips are sanded with a file or sandpaper.

an angle grinder is considered extremely traumatic equipment, therefore, when working with it, you must observe safety precautions and use personal protective equipment (plastic glasses or mask, protective gloves, respirator).

How to cut porcelain stoneware with a jigsaw. Tips for cutting tiles with a jigsaw

To cut holes in a tile, for example, for a power outlet and not chip the tile, you can use a tile jigsaw with a special tungsten thread. To do this, you need to drill a hole in the tile, insert a jigsaw there and start cutting. There is another way. cutting with a jigsaw. A hole is also drilled with a drill, and then a hole is made with a special blade (for example, Bosch Triff).

To cut porcelain stoneware with a jigsaw, you need to stock up on a sufficient number of interchangeable saws (diamond saws for stone) and patience. To solve this problem in large volumes, it is better to use an electric tile cutter.

When tiling walls or floors with ceramic tiles, it is often necessary to cut them. Tile cutting can be done with a jigsaw on tiles. When performing repairs in the bathroom and kitchen, tiles are an irreplaceable material. It can be used to decorate walls or floors, as a wide range of design solutions allows you to achieve an attractive appearance of rooms in this way.

What tools are used

So, how to cut porcelain stoneware tiles at home? Hand tools are ineffective in this case. You should generally forget about the glass cutter. But there is a way out. First of all, it is worth mentioning such a tool, which is available in the arsenal of almost every real owner and craftsman. this is an angle grinder. With its help, you can successfully perform both a straight cut and a curly cut.

Do not use a glass cutter to cut porcelain stoneware tiles.

Another tool is a tile cutter. It is of two types: manual and electric. Since we are talking about porcelain stoneware, it is better to use the electric option. Of course, it will take up more space than an angle grinder or its manual alternative, but the efficiency is impressive.

You can use a device similar to an electric cutter, since you already have nothing suitable. Replace the circular saw blade with a diamond blade and you will get a good tool for working with porcelain stoneware.

How to Cut Porcelain Tile Without Making Mess

For fine work and curly cutting, a jigsaw with a diamond thread is used, it is convenient for them to work, while such a tool will be useful in other areas, not only for laying tiles.

If you intend to cut a large amount of porcelain stoneware, you can ask for help from special firms that provide this kind of service. They have all the necessary equipment for any kind of work. For curly cutting, the method of waterjet cutting is used, but this service is quite decent.

A circular saw

What else can you cut porcelain stoneware tiles with at home? If you are the owner of a summer house or a private house, you probably have your own workshop. One of the most essential tools in this case is a circular saw. It is a toothed disc machine. Since the work is related to the processing of porcelain stoneware, you need to change the attachment to a diamond blade for dry cutting.

After the preparation is completed, the line of the cut is outlined, you can start working. Press the tile against the table and gently push it forward with both hands, taking care of your fingers. This option is suitable for a large amount of work with a straight cut.

Tile cutter

The tile cutter used for adjusting the shapes and sizes of heavy-duty materials is used in the electrical version. It looks like a machine with a diamond disc. In this case, it is recommended to use the wet cutting attachment. On the machine, you can conveniently fix the tile, thus preventing its displacement in the process.

The powerful professional electric cutter will quickly handle large volumes of tiles

How to cut porcelain stoneware tiles with a tile cutter:

  • Fill the drip tray with water. This will ensure cleanliness during operation. In the future, you need to change it often enough so that the accumulated particles do not get on the disk and damage it.
  • Place the tiles on the cutting surface of your tile cutter.
  • Hold the porcelain stoneware with your hands, preferably on both sides, if possible.
  • Press lightly and guide material towards the blade.

From time to time it is necessary to clean off plaque from the disc so as not to reduce the efficiency of the tool.

Material features

Porcelain stoneware gained its popularity due to its unique properties, however, these advantages complicate the process of cutting tiles at home.

The following features of porcelain stoneware should be highlighted:

How to Cut Porcelain Tiles With a Tile Cutter

  • strength;
  • wear resistance;
  • frost resistance;
  • fire resistance;
  • aesthetics;
  • durability;
  • environmental friendliness;
  • hygiene;
  • antistatic.

Due to the almost complete absence of pores in the structure of the material, porcelain stoneware is super strong, it does not scratch, abrade, does not crumble, but that is why it is very difficult to cut it yourself. How to be in such a situation?

We cut porcelain stoneware tiles at home

When working with porcelain stoneware at home, the question often arises. how to cut porcelain stoneware tiles? This material is somewhat very similar to ordinary tiles, but for the most part it has a number of striking differences. In this regard, most of the tools that are successfully used for cutting tiles, in this case, are not at all suitable.

Due to the high strength of the material, not all tools are suitable for cutting porcelain tiles.

angle grinder

The angle grinder is the number one tool that can easily cut porcelain stoneware tiles. To do this, use a diamond-coated nozzle for dry cutting.

The all-round helper for porcelain stoneware tiles. the angle grinder

In order not to mow the cut line and not damage the tile, you must first outline the contours with chalk, pencil or marker. Then fix the porcelain stoneware to a stable surface. The disc is installed in the direction of travel of the angle grinder.

Get to work after checking that the attachment is securely attached. Step back a little from the line mowing line and start working. Move smoothly, slowing down at the edge. The disadvantage of using an angle grinder is a large percentage of the likelihood of chipping, that is, marriage. This is especially true for glazed tiles. Therefore, it is better to consider the option using a tile cutter.

Jigsaw

For complex shape cutting, the best option is to use an electric jigsaw and a diamond saw blade. With its help, you can carry out the finest work even on such a durable material as porcelain stoneware.

A good jigsaw and a special file will allow you to cut high-quality porcelain stoneware

Draw the outline of the cutout. To see where you are going, you can slightly moisten porcelain stoneware with water. Blow off dust as you work so you can see the line and not clog the cutter path.

Work especially carefully on the edges, as these are the places where the risk of chipping is greatest.

When choosing a tool, consider the shape of the tile, the type of coating, as well as the amount of work to be done. Several elements can be trimmed using the tools at hand. But for a large number of tiles, it is better to use a special device. a tile cutter.

Professional advice

Oddly enough, but most of the problems arise not even with the drive or the tool used to process porcelain stoneware, but directly with the diamond disc. The main complaint about the diamond is the rapid loss of cutting ability. As a result, with an increase in feed and force, the edge of the wheel heats up and begins to lose diamond powder. If you try to cut at home in this mode for at least 10-20 seconds, then nothing will remain of an expensive disc.

In this case, before each cut, the edge is cleaned and restored; at home, this can be done on an ordinary red brick by performing several small cuts. This removes soft material adhering to the diamond strip.

Experienced craftsmen, before cutting porcelain stoneware tiles, soak the material in water for 10-15 minutes. Artificial granite absorbs moisture very poorly, but a small amount of water still remains on the edge of the slab. As a result, the first time the cutting edge touches the surface, a beautiful, chip-free entry hole is guaranteed.

How to cut porcelain stoneware with a jigsaw

Quite an unusual way of sawing porcelain stoneware slabs. Using an electric or hand jigsaw to cut very dense and hard material always raises some doubts among beginners. Nevertheless, it is quite possible to cut ceramics and porcelain stoneware with a jigsaw even at home, but only if certain requirements are met:

  • The tool must be prepared for cutting porcelain stoneware. A thin, necessarily soft material is glued to the sole, you can use paper or rubber. This is done in order not to scratch or damage the front surface of the plate;
  • The second step is to turn off the pendulum vibration-movement on the hacksaw blade feed mechanism, otherwise the saw will cut chipped into porcelain stoneware;
  • A special type of diamond-coated hacksaw blade is used for sawing tiles.

In addition, the slab itself must be securely fixed on the countertop with clamps, and a rubber strip must be placed under the porcelain stoneware to reduce vibrations. The method for cutting porcelain stoneware is quite simple and does not require special skills, ideal for use at home. It is valuable that the curly cutting of porcelain stoneware is very easy to perform with a jigsaw.

You can also cut tiles with a hand jigsaw, sometimes at home there is simply no other tool, however, it will take several times longer, but it is possible to get a very accurate and high-quality cut. In this case, the side edges of the hacksaw blade are ground off, and emery powder is fed into the seam during the sawing process.

It is believed that this method is the cleanest of all mechanized options, which is especially important if you have to work at home, without a hood and vacuum cleaner.

How to cut porcelain stoneware with a circular saw

Porcelain stoneware tiles can be cut and cut without any problems using a more powerful cutting tool, such as a hand-held circular saw. Engine speed and power allow you to cut almost everything at home, from wood to metal profiles.

In order to cut porcelain stoneware, the tool must be equipped with:

  • First, a standard carbide-tipped saw blade must be replaced with a diamond disc;
  • Secondly, a bandage ring is placed under the disk fastening, thanks to which it is possible to damp vibrations and uncontrolled bending of a thin and flexible diamond wheel.
porcelain, stoneware, tiles, home

The process of cutting material is not much different from working on an electric tile cutter, the only difference is that the engine power is noticeably higher. Therefore, you need to carefully control the supply of the diamond wheel with minimal effort, otherwise the porcelain stoneware quickly overheats and cracks.

If you need to cut large quantities of porcelain stoneware, then there is no better option than an electric machine.

This method of sawing porcelain stoneware is considered the most productive, but at home it is used for short-term cutting of a small amount of material. You can work only in the yard, in the garage, in the barn, but in no case inside the dwelling. The amount of dust that is generated when cutting even a small amount of material is about an order of magnitude higher than all other cutting methods. The only indisputable advantage of this option is that with the help of a circular and a diamond wheel, you can cut porcelain stoneware at 45 degrees.

Where to cut porcelain stoneware tiles

Oddly enough, but it is the smallest ceramic dust formed when cutting artificial ceramic granite turns into the main problem. At home, it is most convenient to cut the material directly at the place of its laying.

If you plan to cut tiles with a tile cutter, then you can cut out porcelain stoneware in any suitable place for this. The amount of shavings and dust in this case is insignificant, but the performance at home is relatively small.

For curly cutting or cutting sufficiently thick slabs of porcelain stoneware, you will have to use an angle grinder or machine. You will have to work at home either in the courtyard of the house, or you will have to sacrifice a bathroom or a toilet.

How to cut porcelain stoneware tiles at home

In terms of technology, there are two main ways to cut porcelain stoneware. To do this, you can use various tools and devices, but, regardless of the number and type of technical equipment, porcelain stoneware is still cut in two ways:

  • Mechanical sawing of a porcelain stoneware array. In this case, the cutting line is sampled with an abrasive tool;
  • Injection method. On the surface of the porcelain stoneware, a deep scratch is cut along the future mowing line of separation. Further, a bending or shear force must be applied to the porcelain stoneware, and the tile splits exactly according to the markings.

At home, you can use both methods, depending on the tool available, the amount of work and the thickness of the material. In addition, the complexity of the cut line configuration must be taken into account. For example, if you want to cut a tile that is large enough in size at home, which simply does not fit into a tile cutter, then you will need to look for a cutting diamond wheel and an angle grinder. For cutting at home, this is one of the most reliable ways.

Having laid the tiles on a sheet of drywall, you can cut the porcelain stoneware with an angle grinder in almost any trajectory, it is only important to take your time and evenly press the edge of the disc to the surface of the porcelain stoneware. Otherwise, you can easily overheat the tile at the cut point, which will lead to the formation of a pin.

How to cut porcelain stoneware with a glass cutter

The technology for cutting tile material using a manual glass cutter is not much different from the previous method. The only differences are that, instead of a carriage moving along the guides, you have to cut porcelain stoneware with a small tool held in your hand.

In fact, this is ideal if you want to cut material at home. Instead of a frame fixture, a regular table, a metal ruler and the glass cutter itself are used. To cut the porcelain stoneware, it is enough to lay a ruler on the mowing line of the marking and draw a diamond along the mowing line of the cut.

To break the material, the tiles are laid on the table so that the scratch line coincides with the edge of the table top, pressed on top with a board and with a sharp movement break the material into two halves. For home conditions, there is no simpler way, but in order to master the technique, you need to practice cutting on the waste of porcelain stoneware or glass.

The advantage of this method is the simplicity and the minimum amount of equipment required. It is easier to store a manual glass cutter with a diamond at home than a tile cutter. The disadvantage of this method is that it is necessary to learn how to draw a line with a diamond along the markings at a constant speed, and most importantly, to do it continuously, in one motion, while accurately measuring the force applied to the surface of porcelain stoneware.

In addition, it is very difficult to cut material with a glass cutter without chips, therefore, if possible, it is best to use a diamond rather than a carbide roller.

Features of cutting porcelain stoneware

It should be noted that cutting a very dense and hard porcelain stoneware slab is sometimes even easier at home than in the case of ceramic tiles. Those who don’t believe can try to cut overheated ceramics made on old Soviet or Chinese equipment at home. In comparison, cutting porcelain tiles does not look so problematic.

It is quite possible to cut porcelain stoneware without chips, although some masters argue that it is impossible to achieve this in principle. If this were really the case, then most of the walls and steps tiled with porcelain tiles would be with wide seams, curves and unattractive.

It’s not even about the hardness of porcelain stoneware. The technology for the manufacture of artificial granite is such that as a result of pressing and deep firing, material is obtained practically without internal stresses, and this is the guarantee of high quality mowing line sawing.

In order to accurately and accurately cut porcelain stoneware at home, only two conditions must be met:

  • Choose the right cutting mode, ensure constant and uniform pressure with the cutting tool on the line of the cut of porcelain stoneware;
  • Choose the right tool for your specific cutting conditions.

It is clear that at home the possibilities of cutting the material are significantly limited, but even in an apartment it is quite possible to cut porcelain stoneware without a tile cutter, although initially the amount of dust generated when working with electric machines is frightening.

Cutting porcelain stoneware tiles at home

Anyone who prefers to make repairs or do minor work with their own hands must have had to cut porcelain stoneware at home. In the first trials, cutting of porcelain stoneware tiles is more difficult than in the case of cutting tiles. It turns out a lot of scrap, but in general, the process itself is not much different from working with high-quality ceramic tiles.

The cutting line should be marked with an allowance for finishing.