Old and bulky cast iron pipelines can still be found in many apartments. But no matter how reliable they may seem, sooner or later their service life comes to an end. Great solution can be complete replacement cast iron to plastic, but, unfortunately, this is not always possible.

Stops someone financial side issue, others fail to come to an agreement with their neighbors. It is in such situations that the need arises to connect plastic and cast iron sewer sections. There are several methods that allow you to carry out such work quickly, efficiently, and without the involvement of professional help.

The entire complex of work can be divided into four stages:

1. Preparing the work site and the necessary tools.
2. Dismantling of the old pipeline.
3. Installation of plastic pipes.
4. Connection of elements.

To make the connection between a plastic pipeline and a cast iron pipeline reliable and durable, you should prepare everything in advance necessary tools and materials:

• A special hammer with a rubber or wooden head. An ordinary iron hammer will not work here, since it can easily damage cast iron, which is so durable in appearance but very sensitive to impacts.
• Cutting tool. This could be a grinder or a hacksaw.
• Adjustable wrenches.
• Depending on the selected connection method, you may need hand press, thread cutter or welding machine.
• Plastic pipes of suitable size. To connect the toilet to the riser, elements with a diameter of 110 mm will be required to lay pipes to the bathtub and sink the best way plastic with a diameter of 50 mm is suitable.
• Necessary adapters, gaskets, couplings, seals, sealing agents.

Note! Installation of a plastic pipeline must include inspection hatches. Neglecting this rule will significantly complicate repair work if the need arises.

Dismantling an old pipe

The cast iron pipeline must be dismantled very carefully to prevent chips or cracks.

When installing a new sewer system in a house old building You definitely have to make the transition from cast iron to 110 mm plastic. There are different reasons. The most common problem is that old cast iron products are unsuitable for further use. But a complete replacement vertical pipes(risers) often encounters resistance from neighbors. This is where you have to join new ones plastic structures with old and rusty cast iron.

How pipes are connected

Old cast iron sewer systems become unusable. They were replaced plastic products(photo no. 1). They compare favorably with cast iron pipes and have a number of advantages:

• the walls of plastic products have less resistance and become clogged much less frequently;
• plastic is lightweight and easy to install;
• you can install it yourself;
• no special equipment is required for installation;
• Putties and sealants in the form of cords are almost never used;
• plastic products are not afraid of corrosion;
• The service life of plastic products is measured at approximately 50 years.

The disadvantages include:

• if you drain for a long time hot water(60°C and above), pipes may warp;
• very low sound insulation ability.

When switching from cast iron to plastic 110 mm, it is recommended to use special adapters and cuffs. They are made of plastic. If the cast iron pipe has a socket, you also need to purchase an adapter. Let's consider the connection process using the example of a riser with sockets of 110 and 50 mm.

First, the sockets are cleaned. You need to remove all dirt and rust from them, lubricate the rubber cuff with sealant (photo No. 2) and connect the pipes. It is advisable to insert a plastic product into the socket to a depth of 3-8 cm. Such a connection can last at least 8 years. You can use it immediately after docking.

The connection of new plastic pipes with old cast iron pipes without a socket occurs somewhat differently:

• the edge of the cast iron product is leveled with a grinder;
• a rubber adapter is put on this place;
• the edge of the pipe and the adapter are lubricated with sealant;
• new and old products are joined.

Adapters and sleeves must exactly match the diameters of the pipes.

The connection can be made by caulking. This method requires linen winding. The operating procedure is as follows:

• the plastic pipe at the junction is wrapped in several layers of plumbing tape;
• use a narrow spatula or screwdriver to hammer the winding into the gap between the pipes;
• the cast iron product is coated with several layers of a polymer-cement composition made of water, cement, and PVA glue;
• You can use the pipeline in a day or two.

Such joints are quite different good quality and high reliability. You can use this method under the bathtub or under the sink (photo No. 3).

Nowadays it is often used new material- sanitary silicone. This is very effective method connections. To connect pipes you need to perform the following operations:

• The joint must be thoroughly dried with a hair dryer;
• pipes are joined to a depth of 3-8 cm;
• silicone is injected into the remaining cracks using a gun;
• The joint should dry well within 3-5 hours.

It is not recommended to use the sewage system during drying.

Sometimes you have to combine several connection methods. If a gap is formed when connecting products, quite large sizes, can be used rubber gaskets along with the caulking. Corrugated plastic products are connected to cast iron using linen winding along with treating the joint with plumbing silicone. When caulking, you can use silicone instead of a cement-polymer composition. It seals the joint quite well.

Conclusion on the topic

Deterioration of sewer systems in old houses is a fairly common phenomenon. Instead of cast iron elements, plastic structures are installed.

It's quite easy to bark. The most difficult thing in this matter is dismantling the cast iron system. When converting cast iron to plastic DN 110 with or without a cuff, it may be necessary to dismantle the riser. You may need a grinder for this job. But most often the riser is not touched, and only the pipes from the bathtub, sink, toilet and washbasin are replaced (photo No. 4). The joints between the pipes are treated with construction silicone. For work, you should purchase cuffs, sealant, press fittings, and plastic adapters. Everything can be done with my own hands. The main thing is not to rush and perform all operations carefully.

Hello! Today I will tell you how to make the transition from a cast iron pipe to a plastic one.

This article will help you independently hammer out a cast iron sewer for repair. After which it will be possible to install a plastic pipe into the cast iron socket.

What are the difficulties in this task:

1. According to the diameter standard, a cast iron pipe is larger than a plastic one.
2. It is impossible to disassemble the connection without knowing the hardware. The joints look like a single whole.
3. A cast iron pipe breaks easily; you must work extremely carefully with a hammer.
4. The cast iron socket is caulked with sulfur or cement. With different coinages - different way dismantling.
5. When minting sulfur, you will need a torch and a gas mask.

Diameter standards

Let's analyze the situation using the example of a cast iron sewer tee to a bathroom. node

The fact is that it is this tee that is most often changed during repairs, even if it is in working order. It takes up much more space than plastic. And this is important, because with plastic tee The toilet can be installed closer to the wall and further from the door. Well, that is, while sitting on the toilet you can read an encyclopedia.

Tool

The minimum we need:

1. Plastic cuff
2. Sealant
3. Lubrication
4. Hammer
5. Flat head screwdriver
6. In case of sulfur, burner and gas mask

Step 1. Chasing

The method of caulking a cast iron pipe depends on how it is assembled:

1. for cement
2. or "sulphur"

1. Cement

You need to take a small chisel or flat-head screwdriver and gradually, slowly, knock out a small piece of cement. We place the screwdriver in the space between the pipe and the socket. We beat in a circle.

Under the cement there is a heel. A heel is a strand of flax impregnated with oil, which prevents the flax from rotting. We pick out the heel as much as possible.

After this we try to move the pipe. In the case of a tee, it is quite simple to move it: we insert some kind of lever into the outlet of the tee: a block or a long key. If the tee still does not move, then knock out the cement further. Don't use a big lever to force it off. There is a high probability of breaking the socket in which they were going to mount new pipe. Be careful. The work is painstaking and cannot be rushed.

2. Sulfur

Warning: fire. First, we need to ensure complete fire safety. You will be working with an open flame, remove anything around that could catch fire. Have water ready in case you do set something on fire. Air. Ensure the room is fully ventilated. Whether it’s winter or the heat of summer, open the window and door so that there is a draft. Otherwise there will be nothing to breathe. I recommend wearing a gas mask or at least a carbon respirator.

I assume that you can heat the bell with a hair dryer. The melting point of sulfur is approximately 450 °C.

After ventilation has been ensured and Fire safety, turn on the burner and begin to heat the bell evenly. I highly recommend not putting the burner in one place and leaving. Uneven heating cast iron bell may burst. At least I try to avoid such experiments.

It is not necessary to wait for the sulfur to flow out. It is enough to simply soften it with heat. Insert the lever into the tee elbow and move the tee. As soon as it moves, turn off the burner and, shaking it back and forth, move it to the side.

In the case of cement caulking, the same thing: as soon as the tee moves, start loosening it.

Before finally removing the tee, Immediately prepare a rag or other plug for the pipe. They can drain water from above, and there’s no point in breathing in the smell of sewerage.

Step 2. Clean and install the cuff

After we have hammered out the cast iron pipe and removed old site, you need to take care of the cleanliness of the bell.

We clean and wipe it dry so that no lumps remain.

Then we coat the cast iron socket with sealant and insert the cuff (sealant is not always needed).

I throw the cuffs into hot water for about 30 seconds. They become soft and easier to place!

I shared vitalix1974, in the comments on YouTube

Apply lubricant to the inside of the cuff.

Step 3. Insert the plastic pipe

And now all that remains is to insert the plastic pipe into the cuff.

It happens that the pipe does not want to pass into the cuff,

in this case, you can lightly tap the plastic socket to force the pipe into our cuff. Use a board or plywood to distribute the load by tapping with a hammer. Don't knock directly on plastic pipe. It can be broken that way.

Good luck with your transitions!

Today, many people want to replace the old ones with plastic ones. Is this necessary, and if so, in what cases is the transition from cast iron with a diameter of 110 mm to plastic carried out?

Why and what is this for?

There are several cases when it is necessary to make replacement of cast iron sewer pipes with a diameter of 110 mm with plastic ones:

• during the construction of a private house, when it is necessary to “cut into” the central pipeline;
• with a complete update of communication systems, if carried out major renovation homes;
• when installing new or replacing old meters.

When they update plumbing or change the sewer system, they often encounter unpleasant surprises. The most common among them is the presence of old cast iron risers, which need to be somehow connected to new plastic pipes.

But before you begin installation, you need to consider that:

• cannot narrow in the direction of movement of the filling medium;
• the presence of protrusions and burrs should not be allowed, as they will cause clogging of the pipe in the future;
• in cases of liquid transition, it is necessary that the plastic is inserted into the cast iron, and not vice versa. Only in such cases will there be an expansion.

Table. Dependence of price on linear parameters of plastic pipes

In everyday life, plastic pipes with diameters of 50 and 110 mm are very popular for laying water supply or sewer systems. A significant advantage of these products is their reasonable price, as can be seen by looking at the table.

		Length, mm	Price 1 piece, USD
50	1,8	500	0,52
50	1,8	1000	0,97
50	1,8	3000	2,68
50	3,2	1000	1,56
50	3,2	2000	2,92
110	2,2	500	1,22
110	2,2	1500	3,45
110	2,2	3000	6,20
110	3,2	1000	2,92
110	3,2	2000	5,52

Characteristics and range of materials plus GOST standards

To form High Quality industrial products introduced standardization. This also applies to polymer communications. Each enterprise engaged in production is guided by GOSTs. These regulatory documents reflect the main requirements for manufactured products and define them specifications and parameters.

Information on quality indicators and scope of application of polypropylene pipes is reflected in regulatory documents, the main of which is, which began operating in 2003.

Important!

The standard regulates not only the quality, but also determines the main parameters of pipes made of various plastic materials. Plus, the document contains the necessary information used in and.

GOST also defines those indicators that directly affect the service life of products:

1. duration of operation;
2. pressure;
3. temperature range of application;
4. safety factor.

Cuff diameter 110 mm

There are several ways to switch from cast iron to plastic with a diameter of 110 mm. The simplest and cheapest is the transition with a cuff. Preparations for work should begin by dismantling unnecessary sections of the old cast iron pipe. The easiest way to do this is with a grinder. To avoid all sorts of negative consequences, before work you should put on goggles and a respirator.

Approximately from the middle of the pipe, then try to rotate it around its axis, if possible. The rest of the pipe may either burst into several pieces, or you can simply pull it out. In any case, it is necessary to clear the space for the new plastic riser. After this, proceed to clean the outer and inner parts of the socket from the possible presence of rust, old sealant, hardened pieces cement mortar. After this, using coarse sandpaper, polish as much as possible the inside of the bell, dry it, remove unnecessary dirt and dust, and degrease it.

Important!

You should remember that cast iron is fragile, so cleaning must be done very carefully so as not to damage the socket. Now you can begin installation.

To do this you need:

1. Apply silicone sealant to the inside of the bell.
2. Cover with sealant outer part rubber cuff.
3. Place the cuff inside the socket, making sure that it fits completely into the hole.
4. Insert a plastic pipe into the socket, securely fix it and secure it with a clamp or other means.

Since now you can purchase a cuff, adapter, seal of any parameters, in this way you can make the transition from cast iron to plastic not only DN 110, but also for other nominal diameters.

For example, when replacing a section external sewerage use a taper or 110x124, providing smooth transition from cast iron to plastic.

The minimum price of this method of connecting cast iron and plastic pipes is the main advantage of this relatively easy technical operation.

Using a coupling

If you want to connect cast iron and plastic of the same diameter, then use it to carry out this procedure. Before installation, it is necessary to thoroughly clean the desired part of the surface of the cast iron pipe from contamination and rust, and then sand it with coarse and fine-grained sandpaper. Then connect the pipes, and for greater security, tighten the edges of the coupling with clamps. If the pipes different diameters, then you can use a taper or a transition coupling.

Transition with and without bell

Let's consider 2 cases of how you can qualitatively connect a plastic pipe to a cast iron one: with a socket and without a socket.

So, we have a pipe with a socket to which we must connect a plastic pipe.

In order to connect “plastic” to it, you need:

• purchase a cuff of the required diameter;
• clean the bell from dirt and remnants of old embossing, after which it should be dried;
• By inner contour Apply silicone to the socket, making sure that even the smallest recesses are tightly filled;
• apply silicone sealant to the outer part of the cuff;
• insert rubber compressor into the bell;
• insert a plastic pipe into the cuff.

After the silicone has dried, you need to check the functioning of the system.

If there is no socket, you should carefully cut the pipe, clean and align the end. In order to carefully insert a cast-iron riser into plastic, an adapter pipe made of plastic with a larger diameter than in a cast-iron product is often used.

The work is carried out in the following sequence:

• clean the old riser from dirt and dry it;
• in the place of future joining, cover the cast iron pipe with sealant and put a cuff on it;
• Slowly, slowly, so as not to damage the product, put a plastic pipe on the other end of the cuff.

Application of a special press fitting

To eliminate problems in the existing sewer system, as well as when combining cast iron pipes with plastic ones, you can use (see photo).

Its advantage: increased service life (within 50 years!) and the ability to withstand high pressure.

Installation should begin by cutting off a part old pipe, regardless of whether there is a bell or not. To remove burrs, clean the cut end well with coarse sandpaper, straighten it with a file, and then spread it with grease or mineral oil.

After this, you need to cut a thread (4-5 cm wide), onto which you wind a special thread for plumbing work. Then take a press fitting (), and without much effort screw it to the ends of the plastic and cast iron pipe. After supplying water to the system, it is necessary to tighten the connecting product again. Simple and reliable.

In order to make the transition from a cast iron pipe to a plastic one without any problems, you need to follow the practical advice and recommendations of experts.

1. Proper preparations should be made for the repair work. This means that you first need to decide on the area that requires replacement and the amount of material needed.
2. Prepare all the necessary tools: an adjustable wrench, gas (pipe) wrenches, an angle grinder, a mallet or rubber hammer, sealant, etc. Depending on which joining method is chosen, other materials and tools may also be needed during the work.
3. Thoroughly clean the bell from dirt, mortar residues or other old sealant, and sand with coarse sandpaper.

It should be remembered that:

• The easiest way to dismantle old cast iron pipes is with a grinder;
• you cannot break off an old cut pipe, since you cannot foresee how it will break off;
• to avoid chipping, strike the pipe with a wooden or rubber hammer;
• it is necessary to equip an inspection hatch;
• to avoid paying twice, do not use cheap, not always high-quality, Chinese fittings;
• You can get rid of cracks using silicone;
• when using silicone, avoid mechanical impact on the joints for 4-6 hours until the polymerization process of the substance is completed;
• Sealing with silicone is possible only if the joints are completely immobile, otherwise the tightness may be broken;
• You can get rid of old sulfur filling using blowtorch or gas burner. Doing it carefully in any other way will not work. Remember that sulfur vapor is toxic, so it is best to wear a gas mask when performing work;
• to prevent damage plumbing fixtures, it is better to disconnect the bathtub, toilet, washbasin from the system. If you also use it to secure the toilet cement base, then it is better to immediately break it and remove it in parts, since it is unlikely that it will be possible to carefully disconnect it;
• During installation, do not forget that there is a big difference in the coefficients of thermal expansion between cast iron and plastic.

Questions and answers (FAQ)

How to properly connect a cast iron pipe to a plastic product?

Old cast iron structures are gradually being replaced modern systems made of plastic. Therefore, the transition from cast iron to plastic is not uncommon.

To properly connect risers from different materials, necessary:

• accurately select parts in diameter and length;
• depending on the gap between the elements being connected, choose the joining method;
• determine the materials needed for sealing;
• maintain the period of time necessary for the final hardening of the sealant, glue, weld;
• adhere to the algorithm for performing pipe connection work.

Before you start pairing cast iron with plastic, you need to stock up necessary tools and materials.

Only when the above conditions are met can the plastic product and the cast iron pipe be properly connected.

How to switch from cast iron to plastic 50

Plastic pipes with a diameter of 50 mm diverge from the risers to the outlet points. In such areas it is often necessary to make a cast iron-plastic transition. This is due to the fact that many apartments and private houses use old cast iron systems, which gradually fail and need to be replaced with new ones. modern designs. This raises the problem of connecting elements.

It can be solved in several ways, among which we can highlight connections using:

1. Press fittings

When switching from cast iron to plastic 50, a press fitting is used in the form of a coupling with the presence internal thread at the socketless end. This connection is quite reliable, since the thread ensures complete sealing of the seam.

Sequence of work:

• trimming the edges of a cast iron product with an angle grinder;
• chamfering around the perimeter metal part, lubricating this part of the riser with grease, lithol or mineral oil;
• cutting threads 40-50 mm long using a die or thread cutter of the appropriate diameter;
• applying a sealing material to the threads (fum tape, plumbing paste or silicone with tow);
• screwing the press fitting. Please note that during this procedure you do not need to apply special effort, since cast iron is a brittle metal.

Important! To ensure reliable connection, it is advisable to re-tighten the threaded connection after 10-15 days.

2. Rubber seals

If, during the process of dismantling the old section of the system, the remaining part of the pipe is smooth and there are no chips or cracks on it, then this joining option is ideal. Main element– a special rubber cuff, the service life of which is 10-12 years.

The pairing process is quite simple. First you need to clean the cast iron part from rust and dirt. After this, the rubber part is inserted into the socket extension, inserted pvc pipe to a depth of 45-75 mm. If there are sinks, they must be sealed with sealant.

If there is no socket, use a plastic adapter. Cleaning the edges with a grinder and removing rust and dirt is done in the same way, after which a rubber seal and adapter are placed on this part. Then the expanded part of the PVC pipe is attached. All operations are accompanied by silicone sealing.

3. Coinage

When switching to a riser with a cross-section of 50 mm, embossing is often used. This method is optimal if the connection is of the “pipe-socket” type.

It is good to caulk the joining place if there is a gap of 4-6 mm. For smaller distances between the riser and the socket, sealants are used. Minting algorithm:

• apply a thick layer of plumbing paste to the edge of the product and wrap tow;
• place a plastic element in the cast-iron socket, inserting it all the way;
• using a chisel or narrow spatula, fill the gap between the cast iron and plastic with flax fibers to 2/3 of the height of the socket;
• Fill the remaining cracks with a water-cement-adhesive solution.

Important! The pipeline will be ready for use in 24 hours. This is exactly how long it will take for the sealing compound to completely harden.

4. Silicone sealant

If the riser is in good condition, and the gap between the joining elements does not exceed 2.0 mm, then they can be connected to each other using sealant. It should be remembered that the connecting parts must be dry and clean at the joint, and the silicone should be applied under pressure, since this method ideally fills possible cavities and voids.

Important! Operation of the connected parts is possible after complete polymerization of the sealing substance, which occurs after 4-5 hours.

You can also find adhesive connections between plastic and cast iron, joining by welding, and other, less popular methods.

How to switch from cast iron to plastic plumbing

When switching from cast iron to plastic in a plumbing structure, they often use in a non-standard way. Its essence is as follows:

A) Heat the end of a regular (without socket) pipe with a hair dryer or over a flame to such an extent that it becomes plastic.

B) Using your hands (wearing gloves), slightly stretch the heated part to form a kind of socket.

C) Place the stretched pipe element onto the cast iron pipe, making sure that the plastic is evenly placed on the riser along the entire circumference.

After cooling, the connection cannot be removed from the cast iron either by hand or with a hammer. Simple, universal, reliable.

Can also be applied traditional ways docking.

How to switch from cast iron to plastic without a socket

If there is no socket, use a plastic adapter. They work according to the scheme:

• level the cast iron edge with a grinder;
• an adapter is placed on the flat end;
• the “dressed” part of the part is coated with silicone sealant;
• A plastic adapter is placed on the pipe surface, having previously been lubricated with a sealing substance.

General view of the plastic adapter

1- PVC pipe socket

2 – rubber seal

3 – adapter element

4 – rubber cuff

5 – second rubber seal in the form of a ring

6 – socketless riser made of cast iron.

How to switch from cast iron to plastic 110 if you can’t get a cast iron pipe

When replacing a metal product, it is best to cut off a section of the old pipe where it transitions into the socket. With this dismantling option, joining the old cast iron product with a new plastic pipe will take the minimum amount of time and use the least amount of effort.

Important! The best way dismantling cast iron risers - cutting individual sections of the system with a grinder. It is forbidden to break products, since cast iron has isotropic properties and the direction of splitting of a given area cannot be predicted.

When it is not possible to get the pipe out of the socket, then you need to use a grinder to make cuts around the entire circumference every 20-25 mm along (not across!!!) the pipe, reaching the expansion. After this procedure, all unnecessary remains of the risers are removed very easily.

If it was not possible to dismantle the old site metal structure(for example, you cannot get it from concrete screed, and its upper part is located at the same level as the concrete), then you can connect the cast iron and plastic riser using special adapter couplings of appropriate diameters. You can purchase them at any plumbing store.

Video

If you plan to install a new sewer system, the transition from cast iron to plastic will be prerequisite. The reasons for replacement can be different, for example, old pipes becoming unusable, rust, and others.

Very often, when it is necessary to replace old pipes with plastic products, disagreements arise with neighbors, so it is necessary to make connections of a new design with cast iron.

How to properly connect a cast iron pipe to a plastic product?

To connect plastic to cast iron, it is advisable to use rubber cuffs and plastic adapters.

Connecting a new plastic pipe with an old cast iron one

If cast iron has a socket, then you only need to purchase a rubber adapter. In another case, you will also need a plastic adapter.

To understand the process of joining parts, consider specific example, when two sockets are removed from the sewer riser, one is intended for the toilet and has a diameter of 110 mm, the second is for apartment sewerage with a diameter of 50 mm.

First you need to clean the bell well, removing dirt and rust, and then lubricate the inside rubber cuff sealant. It is inserted into a cast iron socket, only after this the sewer pipe is inserted into the cuff.

In some cases, the bell is simply missing, and there is only a small section of the old product. If the edges of this segment are not even, then you should trim them using a grinder. A rubber cuff coated with sealant and a plastic adapter are put on top.

The first method of docking using a rubber gasket

If the cast iron pipe is easily removed, and the inside of the socket remaining from the riser is smooth, then you can use the joining method using special seal. In this case, the plastic pipe is inserted into the cast iron section by at least three centimeters, ideally it should be about eight centimeters.

connecting a bathtub drain with an old cast iron pipe

Using this method, you can quickly make a connection, after which you can immediately use sewer system. Based on practice, it is worth saying that this type of connection will last at least 8 years without problems.

Usually sewer riser consists of two outlets: one for a toilet with a diameter of 110 mm, and the second for an apartment sewer with a diameter of 50 mm. In any case, the connection will be carried out according to one algorithm, in which you need:

• remove rust and dirt from the bell;
• install the cuff on top, and apply sealant to its outer transition;
• the rubber adapter is inserted into the cast iron socket;
• on last stage a new plastic sewer pipe is inserted into the cuff.

installation of a plastic riser instead of an old cast iron one

If there is a need to connect a pipe without a socket, then you will need to use a plastic adapter. In such a situation, the sequence of actions is different:

• The edges of the cast iron pipe are leveled using a grinder;
• a rubber adapter is placed over this area;
• the edge of this pipe with the adapter is coated with sealant;
• A plastic adapter is placed over the treated area, which is also lubricated with a sealing compound.

The cuffs and adapters used must match the dimensions of the pipes. The sequence of connecting cast iron and plastic pipes of different diameters using this method is no different.

Connection using caulking with sanitary linen winding

This connection method is mostly used for joining cast iron pipes, but despite this, it can be used for mixed type docking. If you prefer this option, you need to perform a number of steps:

• on a plastic pipe, the joint areas are wrapped in several layers with plumbing tape;
• Using a narrow spatula or a wide screwdriver, this material must be pushed well into the gap formed at the junction of the pipes;
• The transition to a cast iron section must be coated with a polymer-cement composition several times. This composition is prepared on the basis of cement, water and PVA glue;
• Upon completion of such work, it is not recommended to use the sewer system for at least one day.

connecting cast iron and plastic pipes through an adapter

A joint made using this technology will be reliable and good quality. Earlier this method used quite often, even before the advent of silicone-based sealants. Even now it's convenient solution for connecting a plastic pipe to a cast iron pipe under a washbasin or sink. If leaks appear after some time, this has nothing to do with the docking.

Connection method by sealing with sanitary silicone

If small gaps form during pipe installation, then this method of transition from cast iron pipe to plastic sewer will be effective. When carrying out work, you need to pay more attention to sealing the joint in its lower area.

using plumbing sealant to connect pipes

When docking using this method, you need to perform the following actions:

• first you need to dry the joint well; for these purposes it is recommended to use a hair dryer;
• Using a special gun, silicone is injected into the cracks. The deeper its penetration, the more reliable the connection with the plastic pipe will be;
• It is important that the silicone layer dries well; about 3 to 5 hours will be enough for this. If the layer is large, it will take longer.

During the drying time of the silicone composition, it is not recommended to use the sewer system.

A combination of several pipe joining methods

In order to increase the reliability of joining plastic and cast iron pipes, you can use several methods listed above:

• if there is a large gap at the junction, then it is advisable to use rubber gaskets and caulk them. To connect a toilet using corrugated pipe It is recommended to use linen winding, treating the joint area with silicone. Cast iron crosspieces and rubber seals are also coated with this product;
• When caulking, it is also possible to use not a polymer-cement composition, but a silicone sealant.