Cast iron sewer: installation methods, pipe size, service life

The appearance of a cast-iron sewer is not very attractive. As a rule, such structures were installed in the bathrooms of typical houses of the Soviet Union. Many have associations with just such houses. But do not underestimate the sewerage of this type. Yes, she is not very attractive, but very reliable. And this is not one plus. Of course, it also has drawbacks, and sometimes they turn out to be significant. Let's try to understand as much as possible with all the nuances of sewage from cast-iron pipes.

Main characteristics

Sewerage is a system of pipes that are made of cast iron or any other material. Moreover, there can be both an external and an internal network. It also happens that certain types are used only for the manufacture of a small part of the system, for example, a riser. In a cast-iron sewer, pipes are made of gray metal. In its manufacture, the centrifugal casting technique is used. In order to protect these pipes from corrosion, they are coated with bitumen mastic on both sides.

The advantages of cast iron pipes

Of course, these pipes are very much inferior to plastic. But they have positive characteristics, among which:

1. Compared to other metals, cast iron pipes are less susceptible to corrosion.
2. The material is not combustible, heat resistant.
3. Product resource for more than 50 years. With sparing operation, pipes can last 80 years or more.
4. Very high sound insulation.
5. They can withstand any temperature without any problems.

What about the flaws?

But there are also disadvantages that affect the popularity of this type of sewage system:

1. Pretty high cost.
2. Due to the large weight, the installation of sewer pipes is complicated.
3. Cast iron is a rather fragile material, therefore, when working with it, it is extremely important to observe all safety measures. One careless movement - and the pipe will become worthless.

Types of cast iron pipes

In total, two types of cast-iron pipes can be distinguished, which differ from each other by the connection method. Firstly, these are bell-type pipes that are most familiar to us. At one end they have a bell, that is, a small extension. There are no protrusions at the second end. Due to this design, the smooth edge of one pipe is easily installed in the socket of the second without problems. This connection looks beautiful, but its maintenance is much more difficult.

Secondly, it is socketless pipes that are connected using special clamps. If an internal cast-iron sewage is carried out using them, it is necessary to mask the joints. But most importantly, the maintenance and repair of such a system is much easier to do, even with your own hands.

It is necessary to pay attention to the fact that regardless of the type of connection of sewer pipes, the junction is the most dangerous, since blockages and other malfunctions usually appear in it. For this reason, hatches should be made next to such sections on the pipeline for auditing. In the case of external sewer networks, the functions of the inspection hole go to the inspection wells.

Connection types

In addition to the fact that there are differences in the connection of pipes, they still differ in diameter. For use in residential buildings, 3 standard sizes are usually used:

1. Diameter 150 mm, wall thickness 5 mm. Such are used if they are subjected to high load.
2. Cast iron pipe 100 mm, wall thickness 4 mm. These are usually used to make risers that come from the toilet.
3. Diameter 50 mm, wall thickness 4 mm. Usually installed in order to divert drains from sinks and wash basins, as well as other sources.

When selecting pipes, it is extremely important to consider both the size and the connection method. Check product quality. Be sure to pay attention to such points:

1. On the inner and outer surfaces should not be sinks, holes, other defects.
2. Look at the section of the pipeline, from it you can understand what kind of granularity the material has. It should be uniform and shallow.
3. The wall thickness should be even - this is one of the most important indicators by which you can determine a quality pipe.

How to install pipes

In fact, pipes made of cast iron are currently extremely rarely installed in country houses, since they have many shortcomings. We talked about them above. In particular, if you decide to install the sewer system yourself, it is simply unreasonable to use cast-iron pipes. First of all, you need a wealth of work experience. Secondly, it is much more difficult to lift and mount pipes yourself, you will have to seek help.

The installation of cast iron pipes is not much different from the installation of plastic or asbestos. It is necessary to make markings in the places where it is planned to install pipes. If you are screeding, leave a place under the tee extending from the riser. This must be done in order to subsequently avoid the violation of the integrity of this tee during draft. It is also necessary to determine how the pipe will be fixed on the wall.

The easiest option is clamps that need to be installed on the pipeline below the pipe junction. It is necessary to remove adjacent fixtures from each other by 1-2 m, if the riser is vertical. If the pipes are horizontally located, then the distance should correspond to ten times the diameter.

Using clamps, both rigid and non-rigid joints can be made. In the first case, metal clamps must be tightened as tight as possible. Between it and the pipe you need to install a rubber gasket. In the second case, the gasket is not used, and the clamp is not tightened completely. In both cases, you will avoid creating excessive stress in the pipes.

It is extremely important to maintain the distance from the riser to the wall - it should be about 40 cm. But there is another technique for fixing the pipe, while they are hidden inside the walls. It is necessary to make in the walls for marking the strobes. These are channels whose width is slightly larger than the diameter of the pipe. In this case, you can avoid the appearance of excessive stress in the walls of the pipes. Immediately before laying in this groove, it is necessary to wrap the entire surface with soft material.

If necessary, the pipes are wrapped with a heat insulator. Now it is allowed to apply plaster on the wall to mask the strobes. In this case, you will hide the sewer from prying eyes. After choosing the mounting method, you can proceed with the installation. At the first step, it is necessary to prepare the entire system, fix the clamps or do the strobes. In the second step, you need to collect the entire pipeline. The connection method directly depends on whether pipes with or without sockets are used.

How to connect the pipes? Key Options

In order to perform a socket connection, you must adhere to the following sequence:

1. Twist an 80 mm resin tape into a bundle. With it, it is necessary to wrap the smooth edge of the pipe.
2. Then, with the previously wrapped end, it is necessary to install the pipe in the other bell.
3. Using a wooden narrow spatula and a hammer, you need to hammer the tourniquet into the socket so that this seal occupies at least 2/3 of the connection.
4. Make sure that the gap is the same between the bell and the pipe installed in it.
5. From above it is necessary to fill in a sealant - it can be both sulfur, and cement, asbestos cement.

The last two solutions are used if you need to make the most rigid connection. It is worth noting that it is highly desirable that winding does not get into the pipe. This will immediately lead to clogging.

As for the socketless pipe, the differences are only in the type of connection, it is carried out using a strong steel clamp. Cuffs are inserted on its inner surface. Pipes must be joined to each other, and the joint is fixed with this clamp. Today, plastic pipes are most often used to make a system in homes; it is much easier to install them. But only in old houses, cast-iron sewage is still used. Therefore, if you decide to install plastic, you must first dismantle it.

How to cut cast iron pipes

Sometimes you have to cut cast iron pipes. To do this during repair or installation, you will need to adhere to a certain algorithm. To do all the work as accurately as possible, you need to get safety glasses, a marker, a hacksaw and blades, or a saw with a chain clip. The cutting procedure is as follows:

1. First, let's see how cutting is done with a chain saw. First mark with a marker or chalk a cut line. It is imperative that all lines are flat.
2. Wrap the pipe with a chain. Try to do it evenly. It is necessary that the maximum number of disks be located on the surface of the pipe.
3. Now you need to press the handles so that the saw wheels cut into the surface of the pipe. Please note that you will most likely have to do this more than once to completely cut the pipe. It may also be necessary to rotate it a bit.
4. Similarly, perform cutting in all places that have been previously marked.

You can use a hacksaw machine. For this:

1. Place the blade (long) in the unit and fix it. Typically, blades have carbide or diamond inclusions that make it easy to cut hard metals.
2. Indicate the places where you need to cut the pipe. Make the lines straight and firmly fix the pipe in place. Ask someone to support her during cutting.
3. Cut with a hacksaw. If it is a cast-iron pipe of 100 mm, then it will be easy to saw it. After all, her wall thickness is only 4 mm (the 150th has 1 mm more, so she will have to make a lot of effort).

What are the nuances to consider when connecting bell-shaped cast-iron pipes

Very often, when installing the sewer, pipes are used that have a bell at one end. If you decide to apply them, then you will need to do the following manipulations:

1. First clean the bell and edge of the second smooth pipe so that there is no contamination. Pay attention to the pipe for defects and other foreign objects.
2. Install the end (smooth) of one pipe into the socket of the second.
3. Now you need to increase the tightness of the connection. To do this, you will need to hammer the tow inside the bell. Try to keep material out of the pipe. But this is not the end of the cast iron sewer connection procedure.
4. Next, you need to fill the rest of the space with a cement mortar. It is recommended to use exclusively brands M300 or M400. Cement is bred in water in a ratio of 9 to 1.
5. The solution is poured into the bell, after which the joint is covered with matter (preferably wet). Please note that it is not possible to use cement, but silicone-based sealant, and it is also allowed to use bituminous mastics.

The nuances of connecting smooth pipes

As we noted earlier, they are connected using special couplings, crosspieces, bends. Such cast iron fittings can be found on sale. The connection method depends on many parameters, including the diameter. But still the most popular option is a coupling, which can be of several types:

1. Cylindrical. This is used if the pipes are of the same diameter. There is a thread inside the coupling.
2. The foot is used for heating systems, in fact, it is the same cylinder, but it also has an external thread.
3. Two cylinders - this type of connection is used if it is necessary to join pipes of different diameters. The cylinders also have an internal thread.

If necessary, a cast-iron tee for sewage is installed. It allows you to connect several sources of sewage to the riser.

The joining process is not very complicated, you will first have to outline at what distance the pipes will enter the coupling. Please note that the joint should be clearly in the middle of the coupling. After that, you can install the pipes. To improve the tightness, you can use silicone or bitumen compositions. There are also other devices for connection - these are saddles, tees, crosses, various cast-iron fittings. So, it’s easy to choose the right option.

How to connect plastic and cast iron pipes

Very often during repair there is a need to join a plastic pipe and a cast-iron one. Of course, you can simply insert one into the other, and pour the compound with cement. But at the same time, the plastic will begin to deform. This will cause a leak to appear. It is imperative that the docking site be carefully patched up. After all, various materials are used, they expand differently with increasing temperature. Therefore, depressurization will appear, and after it - a leak. Because of this, the service life of cast-iron sewer is reduced. In some cases, the system even has to be completely redone.

In total, two methods of joining cast-iron and plastic pipes can be distinguished. The choice depends on whether there is a bell or not. Suppose you have a bell in your sewer system, so it’s enough to purchase a special adapter. You can easily install it in the bell. Adapters have diameters similar to standard sewer pipes. If necessary, you can even buy custom adapters. It is installed in a pre-cleaned bell; it is advisable to coat it with silicone sealant. And then this adapter needs to be put in a plastic sewer pipe.

If there is no socket in the sewer system, then you will have to use two adapters of different diameters. An adapter made of rubber is worn on a cast-iron pipe. The surface of the pipe must be thoroughly cleaned and contaminated. A plastic adapter is put on top of the rubber adapter. The sewer must be installed just in it. But do not forget that all joints must be treated with sealant. This will prevent the appearance of not only a leak, but also an unpleasant odor.

That's all, the pipe docking is complete. By the way, such a connection is very easy to disassemble if necessary. As you can see, the installation of cast-iron sewer pipes is quite simple, but you will have to do work as a team.