Home Improvement

Doing the plumbing in the house

A side-view shot of a man standing in his bathroom looking at his toilet, there is a problem, he is on the phone trying to call a plumber.

Out-of-town homeowners have to think about how to get water to the house. So how do you choose the right materials for the plumbing? Let’s try to figure it out.

So, you have a source of water. It may be a well, a well with drinking water or a technical well on the street, in which there is a utility pipe and is expected to connect yours (tie-in). In any case, the outdoor pipeline for year-round use should be deepened below the frost level, so that the water in it does not freeze even in the most severe and prolonged frosts.

What kind of pipes will be?

Twenty years ago with the pipes everything was simple and clear: they used steel galvanized metal pipes, less often cast iron. Now the range of pipes for water supply has significantly expanded.

Pipes for country plumbing choose based on their technical characteristics, durability, ease of installation and, of course, the cost. The most widespread are pipes made of polymers (polyethylene PE, polypropylene PP, PVC polyvinyl chloride, etc.) and composite materials. The latter include metal-polymer pipes and polymer pipes reinforced with fiberglass.

Choosing the material


Polypropylene pipes have a low price.  Water leak detection in such pipes is not required, because they are very wear-resistant. Polypropylene is rigid enough, the pipes hold their shape well, but they cannot be bent. Connection of PP-pipes and fittings are made by welding. This requires a special tool. The main disadvantage of PP-pipes is the high temperature deformation when heated. Some models of such pipes can not be used for pumping liquids with temperatures above 60 ° C. For example, these are pipes made of random copolymer propylene (designated PP-R). Now manufacturers are moving to thermally stabilized polypropylene (PP-RCT), which is designed for a liquid with a temperature up to 85 ° C, provided that the pipes will be arranged temperature compensators. In their role are the individual bent sections of the pipe or U-shaped inserts.

Low pressure polyethylene (HDPE).

Refers to one of the cheapest types of pipes. Coil of pipes with a diameter of 20 mm and a length of 25 m. HDPE pipes can bear temperatures well below zero and are often used for the installation of outdoor plumbing, but they are not generally suitable for water temperatures above 40 ° C.

Metal plastic 

These are multi-layered pipes in which the outer and inner layers of the pipe wall are made of polymer materials and between them there is a layer of aluminum. MP pipes are designed primarily for heating, as their design eliminates the diffusion of oxygen through their walls. But they are also used for in-house distribution due to a number of design advantages: they are flexible, while holding their shape well and do not give appreciable temperature deformations. In addition, they are easy enough to install using crimped removable fittings. Such advantages have led to the widespread use of MT-pipes, even despite their comparative high price (their price is about 1.5-2 times higher than that of PP, fittings also cost about twice as much). It should be remembered, however, that removable fittings are not the most reliable installation mechanism. Condition of such connections should be checked and inspected every six months to a year. If the connection is loose, it should be tightened. Splice fittings should not be installed in concrete screed or any other method that precludes access and inspection. 

Cross-linked polyethylene

Cross-linked polyethylene is polyethylene that has been treated in a special way (e.g. chemically or with UV-radiation) so that a chain of molecules is connected to each other. Such material is quite strong, chemically very resistant and durable. The pipes can be used for both cold and hot water supply. They are used with fixed crimp fittings and are generally one of the most reliable options. The elasticity of the walls protects them from damage from bending and squeezing. The only restriction is that cross-linked polyethylene must not be exposed to direct sunlight.

Technical markings on pipes

All the necessary information is usually indicated on the pipe. This is, firstly, the type of pipe and the material from which it is made. Also, may specify a diameter and nominal working pressure (marking PN is not currently mandatory, but is often used to indicate the allowable working pressure at a temperature of fluid 20 ° C). For example, PP-R DN32 PN10 is a polypropylene pipe having a diameter of 32 mm and designed for a pressure of 10 bar. Or, for example, PP-R/PP-R GF/PP-RCT (SDR11). It looks scary, but in fact it is a three-layer pipe, the middle layer – fiberglass-reinforced polypropylene, designed for pressure of 20 bar. And the SDR – it is a parameter specified according to European regulations, instead of the outdated PN. Dimensionless value indicates the ratio of the outer diameter of the pipe to the thickness of the polymer wall. The smaller the value, the higher the pressure the pipe can withstand. SDR6 means that the pipe will withstand pressure of 25 atm, SDR11 – 12 atm, SDR26 – 4 atm.

Manufacturers often use color markings: pipes with a red line are designed for hot water, with a blue line – for cold water. In general, with some skill, it is quite possible to learn to understand all these designations. 

What’s new on the market of pipes and fixtures?

Of the innovations, let’s note primarily the various modifications of fittings, which are becoming every year more reliable and convenient. All connection technologies can be divided into two classes – separable and inseparable. The first class includes threaded, threaded clamp and flange connections. A common disadvantage of all detachable joints is their loosening over time and, as a consequence, violation of strength and tightness. Such connections must be periodically tightened. Therefore, according to building regulations, it is prohibited to lay pipes with detachable elements covertly. Non-detachable joints do not require regular maintenance and allow for concealed laying of pipes with them. The axial press connection with slip-on sleeves is considered one of the most versatile and ensures a fully tight connection.