Grounding a bath in an apartment: why and how to properly ground a bath

Types of baths and features of their grounding

If you think that an acrylic bath is a dielectric and does not need to be grounded, you are mistaken. It, like other similar products, has a metal frame, and it is filled with a liquid that is not a dielectric. By the way, the liquid in the bath is somehow connected with the water in the plumbing and other plumbing fixtures - a kind of circuit is formed along which the static voltage moves, regardless of the material from which the bath is made. That is precisely why it is necessary to ground not only a cast-iron and steel bath, but also an acrylic one.I will say more, according to all the rules, it is necessary to ground even a shower cabin.

Now a little more about how to ground the bath, depending on the material of manufacture.

1. Grounding a cast iron bath. If we are talking about connecting a modern cast-iron bathtub to the ground loop, then everything is simple here - it already has a special eye with a hole made in the factory. The so-called petal just serves to install a bolt with a nut and washers into it, through which the ground wire is connected to the cast-iron bath. Things are a little more complicated with old cast-iron bathrooms - before such a petal was not provided, and you will have to make it yourself. The situation is slightly complicated by the fact that it will not be very correct to connect the ground wire to the legs - there is no proper contact between them and the bath itself. This issue is resolved as follows. In the area where the legs are installed, there are special processes from the bath body, which serve to wedged the legs - here in them it will be possible to drill a hole up to 10 mm deep, cut a thread in it with a tap and screw in a screw with a washer and nut, thus providing a reliable grounding contact directly to the cast-iron bath body. As an alternative, bathtub wings can be considered - they can also be drilled with a hole up to 5mm. In this case, you have to guess with the length of the screw.

Grounding a cast iron bath photo

Grounding of a steel bath. Grounding a modern steel bath does not present any problems at all - as in the case of cast iron, it has a special tab to which a grounding cable is connected.There is, however, one caveat - in order for the grounding to be complete, around the hole into which the crimp screw is installed, it will be necessary to clean off the enamel down to the metal itself.
Grounding an acrylic bath. It has already been mentioned above that acrylic is a dielectric and does not conduct electricity, but like all similar materials, it is capable of generating static voltage itself, which accumulates on the metal frame of this bath - it is this that must be grounded. In most cases, a grounding lug is provided on the frame, but in some designs it is not. This issue is solved, as in all previous cases, with the help of a drill and a drill - a hole is made into which a crimping screw is installed. Do not forget to remove the paint around the hole - it is a dielectric!

This is how the issue of grounding in the bathroom is solved with almost all metal products - a wire, a hole and a bolt with a left-hand thread. Kidding. Most products, especially powerful electrical consumers, are already equipped with terminals or at least holes for connecting the ground loop.

Jacuzzi bath grounding photo

And in conclusion, a few words about the grounding of the hot tub or, as it is now commonly called, a jacuzzi. The question of how to make grounding in a bathroom equipped with such a plumbing fixture should be addressed in the very first place - this is your safety! You should know that you are going to take a bath, which is crammed with all sorts of electrical equipment.

The jacuzzi must be grounded with a separate powerful cable, one end of which is connected directly to the plumbing fixture itself, and the other to the grounding input to the house (usually it is located before the switchboard).

That, in principle, is all you need to know about how the bath is grounded. To summarize all of the above, we can distinguish three main points based on which such work is carried out: a powerful copper cable with a cross section of at least 6 squares, reliable contact and connecting the bath directly to the ground loop to the switchboard. And finally, let me remind you about such a product as an RCD - all electrical wiring in the bathroom must be connected through it without fail.

Grounding bathtubs of different types

How to ground baths of old models:

To ground the old-style bath, make a hole in the leg and pass the wires through.

If the bath is of an old design, then to ground it, drill a hole in any leg through which you can pass a stranded wire. Use a nut, washer and bolt to fasten a grounding jumper or, alternatively, a stranded wire to the foot of the tub.

On the other hand, the grounding jumper is attached to a special distributor. Wires from other metal and electrical appliances in the apartment should also be connected to the same distributor. The electrical distributor can be mounted on any convenient wall, but preferably not in the bathroom. The distributor is required to make a mandatory output to a common grounding shield, which is most often located in the entrance.

How to ground a cast iron bath:

Cast iron bathtubs from the factory already come with a grounding device - a petal.

Cast iron bathtubs, like bathtubs made from other metals, already come with a special grounding device called a petal. To this tab, using a nut, washer and bolt, you need to connect a bare section of a stranded ground wire.

If the bathroom is equipped with a shower with an instant water heater or an electric water heater, which have a sufficiently large capacity, then reliable grounding is definitely required in this case. The ground jumper is carried out in the form of a connection of all metal parts with grounded pipes.

How to ground an acrylic bath:

Bathtubs made of acrylic are especially popular among consumers because they are relatively inexpensive, lightweight and easy to use. Although acrylic is not a metal, and therefore is not a conductor of electric current, grounding an acrylic bath during its installation is simply necessary. Why, then, ground the acrylic bath?

The grounding device is attached to the metal base of the acrylic bath.

First of all, acrylic bathtubs are available both cast and extruded. It is extruded acrylic bathtubs that do not hold their shape well and therefore are always equipped with a metal base, which requires mandatory grounding.

Also, acrylic, as a dielectric, is able to create some kind of static electricity. And if you draw water into a bath of this material, then, depending on the area of ​​\u200b\u200bthe container itself, an appropriate electric charge will accumulate. Therefore, the grounding device is attached directly to the metal base of the acrylic bath.

How to ground a hot tub:

Recently, hot tubs have become popular, the work of which is based on the use of electric current. The hydromassage system of such a bath is connected to a network with a normal voltage of 220V and a frequency of 50 Hz.

Due to the fact that the hot tub is powered by electricity, grounding is a particularly relevant issue.

For such equipment, before grounding, it is necessary to equip a separate grounded socket, which is equipped with a separate plug and wire with two insulating layers. This plug is a direct grounding device. Due to this, water does not fall on the surface of the outlet and a short circuit cannot occur, which is why the outlet is often called waterproof.

It is best to install a moisture-proof socket on the wall before grounding. At the same time, the height of its location from the floor level should be at least 30 cm and from the outer side of the hot tub - at least 50 cm. Such safety measures are observed to prevent possible water from entering the socket. The connection is made with a separate wire with a double insulating layer.

When, as well as a washing machine and an electric water heater, a special 16A machine is required that regulates the voltage of electricity. Such a machine is recommended to be installed in the hallway or in another room, but not in the bathroom.

It is strictly forbidden to use a hot tub in everyday life, the socket of which does not have a special grounding contact.The bath must not be grounded by plumbing, sewer or heating equipment. Do not perform maintenance while the hot tub is running and do not use the hot tub if the grounding is faulty or the power cord is damaged.

What is grounding and why is it needed?

Before starting work, you need to deal with the theoretical part of the issue. What does the very concept of "grounding" mean, is it really so necessary and why is this issue so acute in the bathroom. This knowledge will help you figure out whether you really need to ground the bath in the apartment.

Explanation of the concept of "grounding"

Electric current is a rather dangerous thing, especially when handled ineptly. Needless to say, in combination with water, completely harmless electrical appliances get out of control and become deadly.

From the course of physics we know that the current always moves along the path of least resistance. The task of grounding is to work so that even in the event of an unexpected breakdown of an electrical appliance, the person who is at that moment near it does not suffer.

Earth can play the role of zero potential. This property makes it possible to safely use electricity in everyday life. "Grounding" means to connect the electrical wiring network to the ground with a suitable conductor.

It is often quite difficult to perform such an operation in apartments, especially in high-rise buildings. Use another method - zeroing.

This is a fairly popular method, but there is a significant drawback. The machine doesn't work instantly. That is, between the theoretical shock and the knocking out of the RCD, some time passes, albeit a few fractions of a second.If the voltage is high, and the path of the electric current passes through the heart, even a second can be fatal.

It is much safer to ground, although it is more difficult in terms of implementation. The potentials in the circuit formed at the time of the breakdown (between the phase and the ground) are equalized instantly, and nothing threatens the person.

Why is it necessary to ground the bath in the apartment?

Based on the above, grounding appliances in the bathroom is a common safety measure that should be done by default. Unfortunately, proper grounding is rarely found in modern apartments. Not everyone fully understands what it is and why it is needed in the bathroom.

Previously, when water pipes were exclusively metal, the issue of grounding was not raised at all. Without exception, all the baths were somehow connected to the pipeline, and that, in turn, went underground, thus creating the same grounding.

Steel pipes are now being phased out in favor of plastic pipes. Even if you still have a metal pipe, you cannot be sure that the neighbors below have not changed their part of the riser, thus breaking the chain. Therefore, it is better to play it safe and protect yourself and your family.

In addition, in those days when many apartment buildings were being built, there were practically no electrical appliances in the bathroom. Even an elementary socket was a rarity.

Now in the average bath you can count about 5 permanent electrical appliances:

• electric water heater;
• washing machine;
• heated towel rail;
• hair dryer;
• electric shaver.

Any of these and other devices can cause voltage on its case. The consequences can be dire.It is better not to neglect the grounding device even before dangerous situations arise.

Features of grounding bathtubs from different materials

Steel or cast iron tubs are excellent conductors. It is these models that need to be grounded in the first place. Old-style bowls are connected with a ground wire for a metal leg. To do this, a hole is drilled in the latter and a special plate is installed - a grounding jumper.

More modern models are already equipped with an overlay on the body - a petal - even at the stage of release from the factory.

The acrylic bathtub is made of a polymeric material, which is not a conductor of electric current in itself. However, acrylic tends to accumulate static electricity.

Some models are designed in such a way that the bowl is held by a steel or aluminum frame, which must be grounded.

Hot tubs or whirlpools are equipped with a system of jets through which water is supplied under different pressures. To make the bath work, you need a pump. And it is powered by a 220 V electrical outlet.

In addition to the mandatory rules for connecting this kind of baths, such as the safe installation of sockets in the bathroom (no closer than half a meter from the edge of the bowl and ground level and the presence of protection not lower than IP44), it is imperative to ground the bath itself, just in case.

The need to ground the bath

Let's start with the basics. What is called grounding? This is a protection that takes current from the body of an electrical device and diverts it to the ground. A fairly large number of devices are equipped with metal grooves designed specifically for grounding.

Why is it so necessary to ground the bath? Everything is simple.Water conducts electricity perfectly, which means that in the bathroom there will always be a potential danger of encountering the action of electricity. And given the fact that the bathroom has a lot of metal pipes and various products, combined with high humidity, it is imperative to ensure proper grounding in order to avoid accidents.

Everything that is made of metal, but does not apply to electricity: a battery, pipes, a bath, and others, can play a cruel joke when a fuse is triggered. Once upon a time, the bath was grounded by connecting it to a riser: sewer or water. But now this method cannot be applied! If suddenly your neighbors on the floor below want to replace the metal riser with a plastic one, the grounding effect will disappear. Plus, the area of ​​the capacitor will increase many times, and this leads to even more serious consequences.

Grounding rules

In order to make the grounding of a metal (steel or cast iron) bath in an apartment, in accordance with the requirements of the PUE, it is necessary to make connections according to the attached diagram:

In order to ground all metal parts in the bathroom, you must first install the potential equalization box. You can make it from any terminal or junction box containing a zero bus with the required number of terminals. The box is connected to a PE or PEN bus located in the inlet or floor panel. Next, you should make a connection to the potential equalization box of the following metal parts (essentially ground them):

• body of a metal bath;
• pipelines of hot and cold water supply;
• shielding mesh covering the underfloor heating cable, if any.

Typically, metal bath designs contain special contact elements for attaching a ground wire to them. The cross section of the wire for grounding the bath must be at least 2.5 mm2. For these purposes, you can choose a wire brand PV-1. In the absence of such a contact, you can make it yourself: weld a bolt in the lower part of the body, for subsequent fastening of the grounding conductor under the nut. For this purpose, it is better to use a tide on the body, designed to install a removable leg. The photo below clearly shows how to ground a cast-iron bath in an apartment:

If the bath is acrylic, you can ground it using a metal frame on which the bowl is installed. Despite the fact that acrylic is a dielectric, it is still capable of heating up static electricity, as a result of which it is possible to get an electric shock from the bath. The organization of protection will protect against this.

In addition, electrical outlets located in the bathroom (as in other rooms) must have three pins, with a PE or PEN conductor connection.

Grounding a hot tub is not fundamentally different from grounding a conventional design. Whirlpools are equipped with electrically driven pumps, the case of which must be grounded by connecting it to a protective earth conductor. Hot tub grounding diagram is shown below:

It should be added to the above that, in accordance with paragraph 7.1.48., The installation of electrical outlets in the bathroom in the apartment is allowed subject to one of two conditions:

• the socket is connected to the network through an isolating transformer providing galvanic isolation;
• the socket is protected by a residual current device (RCD), with a differential current setting, not more than 30 mA.

When reading the PUE, a natural question arises: how to properly ground the bath in an apartment located in an old house, for example, in Khrushchev, where there is no protective ground conductor? Is this activity required or not? In this case, it is necessary to bring the grounding system in line with the PUE, that is, switch to the TN system. There can be no other answer to this question.

Home craftsmen should be warned against unskilled actions in this direction. In systems without protective grounding, the bathtub should not be connected to water supply pipes, heating pipes or to self-made grounding

Please note that the system of measures aimed at ensuring safety, in particular in the bathroom, is referred to in the PUE as a "potential equalization system" and not "grounding". This has a deep meaning, expressed in the fact that the goal in itself is not grounding, but the prevention of the possibility of a person falling under the influence of a difference in electrical potentials.

The potential equalization system, as a means of protection, loses its effectiveness after the use (even episodic) of water conduits with plastic pipes. In this situation, a properly installed and sensitively configured residual current device will help protect against an accident. About, how to connect RCD to the network, we told in a separate article.

In the video below, you can also view an expert's opinion on how to organize the grounding of a bath in an apartment or a private house:

That's all we wanted to tell you about how to make a do-it-yourself bath grounding in an apartment. Consider the requirements of the PUE and our recommendations in order to ground the structure correctly and be safe!

You probably don't know:

• Single-phase RCD connection diagrams
• How to make grounding in the bathroom
• How to choose bathroom fixtures

How to Ground a Bath

Bathtubs come in three main types:

With the grounding of cast iron and steel baths, there are no questions. But is it necessary to ground an acrylic bath and why? Earthing opponents claim that acrylic is an insulator and grounding such a bathtub does not make sense. Proponents argue that acrylic is very good at accumulating static electricity, and grounding is necessary to remove static potential.

In fact, static voltage, although it has a high value, is absolutely safe, since it has a very low power. And in rooms with high humidity, static electricity does not accumulate at all. And how to ground a plastic bath? The metal frame of the acrylic bathtub is surrounded on all sides by non-conductive plastic. Therefore, grounding an acrylic bath makes absolutely no sense. And its efficiency is the same as that of a grounded toilet.

The effectiveness of grounding a steel or cast iron bath is high and is mandatory if there is electrical equipment in the room. Modern bathtubs have a special mount for connecting a grounding conductor (fig. below).

Earth connection to steel bath

Old designs did not provide for grounding, so grounding must be done independently. Metal bathtubs can be equipped with single and removable legs for installation on the floor. The legs, made as an integral part of the bath, allow you to attach the grounding directly to them. The easiest way for this purpose is to drill a hole with a diameter of 4 ... 6 mm in one of the legs with a drill. It is necessary to drill a hole in such a place of the leg so that it does not disturb the appearance and does not reduce the strength of the structure, since the cast-iron bathtub is heavy.

Grounding cannot be attached to removable legs, since the contact between the leg and the bath body tends to oxidize from high humidity, and is subject to deformation due to frequent temperature changes.

In a cast-iron bath, you need to find a place where the thickness of the metal is maximum and drill a blind hole there. This is best done near the side of the bath. The hole is threaded.

The main difficulty of this method is that the integrity of the enamel coating is not violated due to the large depth of the hole. At the same time, for reliable fastening of the screw in the through hole, it is necessary that it be screwed in several turns. For a screw with a diameter of 6 mm, the diameter of the hole should be 5 mm, and the depth should be about 5…6 mm. For threading, a tap is used, in which the pointed front part is ground off. This is done in order to cut the thread to the greatest possible depth of the hole.

If the removable legs are attached to the bathtub with bolts, they can also be connected to earth (fig. below).

Ground connected to the foot of the bath

In a steel bath, a hole can be drilled in the side wall of the rim facing the wall.

In all cases, the ground connection point is thoroughly cleaned of dirt and enamel. Fasteners should not have a galvanized coating, since the copper of the conductor and zinc will make up the so-called electrochemical pair, and the junction of these elements will quickly be covered with a film of oxides that conducts electricity poorly.

For the grounding conductor, a copper flexible wire with a cross-sectional area of ​​​​2.5 ... 4 mm 2 is taken. If possible, the wire should be insulated. At the end of the wire stripped of insulation, a ring is made. The ring is attached to the bath through a drilled hole using a bolted connection. To avoid crushing the wire loop with a nut or screw head, a steel washer must be laid between them and the loop. The concrete screed, in which the wire will be embedded, releases aggressive substances when dried, which can damage the ground conductor.

The ground connection to the housing must be covered with bituminous mastic to protect against corrosion.

5 Grounding of bathtubs and other potentially unsafe devices and objects

Each device must have a separate conductor. Grounded devices must not be connected in series to the grounding bus of the shield. As a grounding conductor, copper with a cross section of at least 2.5 mm2 should be taken if it is mechanically protected, and 4 mm2 when there is no such protection. It is also allowed to use aluminum and steel conductors with a cross section of at least 16 mm2. It is advisable to use insulated wire. We clean it both ends, on which we then make a ring for fasteners.Let's start with the usual showers and bathtubs. They are equipped with a special mount - an eyelet. If necessary, we clean it at the place where the fasteners are installed (a suitable bolt with a nut and washers that will protect the wire loop and eyelet from being pressed through) from enamel, dirt or rust to bare metal.

Proper bathroom grounding

In old metal baths, grounding is not provided. If their legs are an integral part of the entire product (not removable), then we drill a hole in one of them with a diameter of 4–6 mm for the corresponding bolt with a nut and washers. It is necessary to drill in such a place that the hole does not reduce the strength of the leg, and the fasteners and the ground wire do not spoil the appearance. Before fastening the conductor, the area around the hole on both sides must be cleaned to bare metal.

It is impossible to ground the removable legs, since the contact between them and the metal bath itself deteriorates significantly over time, or even disappears due to oxidation and even rusting of their adjacent surfaces from high humidity, as well as deformation caused by frequent temperature changes. But if the racks are bolted to the bathroom body, then you can connect the ground to one of them. When there is no such fastening of the legs, proceed as follows.

In a steel bath, we make a through hole at the side on the side facing the wall. In the cast iron on its outer side, we drill a blind hole with a diameter of 5 mm in the place where the maximum thickness of the metal is. Better near the edge. Then we cut the thread for a bolt with a diameter of 6 mm (with a washer). The main thing is not to get a through hole instead of a deaf one and not damage the enamel coating inside the bathroom.But the depth of the hole should also be sufficient - 5–6 mm, in order to establish grounding reliably and with good contact. A tap for threading will need to grind off the pointed nose. This will allow you to cut deeper.

What if the bathtub is acrylic? Made by extrusion, it comes with a metal frame-stand. If it does not have a special ear for grounding, then we drill a hole. If the acrylic bathtub is cast, then it usually should have a special jumper. When it is not there, we act as with a metal bath - we drill a hole. Grounding an acrylic plumbing fixture will also protect against static electricity that accumulates on it when there is relatively little humidity in the bathroom.

This is necessary so as not to receive a “hello” from a neighbor in the form of a current discharge. How this happens was mentioned at the beginning of the first chapter. To do this, you can use steel clamps with holes. All ground connections must be covered with bituminous mastic so that they do not rust. All conductors should be brought into a potential equalization box (PEC) installed in an inconspicuous place in the bathroom. This is a common plastic junction box with 1 common bus. And already from it we pull 1 insulated wire of the same section to the grounding bus of the shield.

How to ground a modern cast iron or steel bath

Grounding modern bathtubs is also a fairly simple and quick process, and hardly anyone will have difficulty. All bathtubs already have special petals for carrying out the necessary work.You just need to tighten the bare end of the wire between the washers and then bring the other end to the ground bus. This option is efficient and effective and guarantees safety.

As for steel baths, everything is also extremely simple and clear. A special "eye" is also present and no drill is required for operation. To begin with, it is worth stripping the enamel coating around the hole directly on the petal, and fix the end of the wire with a crimp screw. Next, it is worth acting by analogy with a cast-iron bath, no problems are guaranteed.

It is worth knowing that in no case should you connect the ground to the steel legs of the bathroom made of steel or cast iron. This is due to the fact that there is no normal contact between the bath and the supporting elements. Over time, the joint between the leg and the pan can rust or oxidize, causing a lack of contact.

Do I need to ground a cast iron, metal or acrylic bath

Do I need to ground the bath? This question worries many people who are going to make repairs in their home. The equipment of modern apartments is distinguished by the presence of all kinds of household appliances and electronics.

For the convenience of connecting them in a house or apartment, sockets are installed everywhere, including the bathroom.

Grounding the bathroom will protect against sudden current discharges, and avoid such a common problem when the faucet in the bathroom is shocked.

Bathroom grounding

The modern bath is one of the most dangerous places in the house. In most cases, they are made of metal, which is a good conductor of electricity.

Often sockets and additional light switches for convenience are installed in close proximity to the bowl body itself. There is a certain risk to human health (electric shock).

Therefore, in order to avoid the sudden appearance of an electrical discharge, it is necessary to ground the bathroom in the apartment.

In our country, the requirements for this procedure are regulated by special rules and regulations. Therefore, it is best to seek help and advice from experienced professionals.

At its core, the grounding of the bath is the connection of the body of the bowl with a wire, which in turn has a connection to the ground (floor).

If it is, then the charge (including the statistical one) that suddenly appeared on the body will “leave” into the floor without causing trouble.

How to ground a bath?

Bathroom ground connection diagram

In the old days, grounding in the bathroom was done in the most primitive way: they stretched the conductor from the bath to the water riser.

Today, the entire water supply system is made of polypropylene (plastic) pipes, so this option is completely meaningless. From the bathroom there must be a special connection to the ground bus, which is located on the distribution board.

How to make grounding in the bathroom correctly? It all depends on the material of the sanitary ware.

Grounding an old-style bath

Bathtubs made during the Soviet period are still found in many apartments. However, not everyone knows how to ground a steel bath produced in these years, and whether it is worth doing it. Each old-style plumbing product has approximately the same design. Therefore, their grounding is carried out according to the standard scheme for them.

A grounding jumper is threaded into the foot of the bath. If the leg is solid, then a through hole is pre-drilled in it. Then the jumper is fixed with a nut and bolt.

Also, for clarity of the process, you can learn how to make the grounding of the bath by referring to the video material:

Grounding a cast iron bath

Grounding a cast iron or metal bath

Do I need to ground a cast iron bath? The answer is obvious - it is necessary. Cast iron is a metal, therefore, like any other material in this category, it is an excellent conductor of electric charge. And at one fine moment, this property can lead to a very unpleasant problem: "the water in the bathroom is electric."

All modern cast iron plumbing already has a special device (petal) for connecting the ground wire. Its fastening initially involves the use of a bolt and nut. In the future, the grounding of the cast-iron bath occurs according to the standard scheme described above.

Note! It is mandatory to install an earthing system if the mixer with shower is connected to an instantaneous water heater, which differs from the storage boiler in greater capacity

How is the grounding of the bath

Grounding is a special protection that, when an electric charge occurs on a certain case, takes the current and leads it to the ground. Modern electrical equipment, as a rule, has special metal grooves for ground wires. And if certain security measures are not taken, a person can be electrocuted, in some cases this can have a rather bad end.

Bath grounding scheme.

As noted above, the bathroom in this regard is the most dangerous place. Since it is there that a large percentage of humidity accumulates in the presence of a variety of metal equipment and electrical appliances. A threat to human life arises because quite often electrical wiring is designed without appropriate safety measures.

It is very important to make the bath grounding and to prevent the appearance of voltage on objects in the bathroom. Other bathroom items that have absolutely nothing to do with electricity, such as plumbing and drain pipes, central water pipes, radiators, bathtubs and sinks, can also lead to a tragic ending if a fuse blows.

In this regard, today many are interested in: why is it necessary to ground the bath and how to prevent the occurrence of dangerous voltage on objects located in the bathroom

Other bathroom items that have absolutely nothing to do with electricity, such as plumbing and drain pipes, central water pipes, radiators, bathtubs and sinks, can also lead to a tragic ending if a fuse blows. In this regard, today many are interested in: why is it necessary to ground the bath and how to prevent the occurrence of dangerous voltage on objects located in the bathroom.

Previously, this problem was solved in this way: the bath body was connected to a water pipe or sewer riser.

But today this method is considered irrelevant, because neighbors living below the floor can at any time within their apartment change a metal water pipe or sewer riser to plastic equipment.