Polymer sand wells: design, advantages and disadvantages, installation rules

Drainage, water supply, external sewerage and stormwater systems include various well structures.Previously, they were built from wood, then from brick and reinforced concrete. But now polymer and composite materials are being used more and more.

One of these options is a polymer sand well made from prefabricated elements. Why is it so good, is it possible to assemble it with your own hands? It is these questions that we will examine in detail in our article.

We will also consider the components of a polymer sand well, the features of its use, the main pros and cons.

Device and characteristics

Initially, the walls of well shafts were reinforced with frames made of water-resistant wood. Then they began to do this using reinforced concrete rings.

But in the last decade, they have been replaced by composite building materials, which in terms of strength characteristics are not inferior to concrete, and in terms of ease of installation, are significantly superior to it.

Elements of a polymer-sand well are produced from:

• plastic (recyclables in the form of waste from various polymer products);
• fine sand with humidity from 0.1 to 10%;
• multi-colored pigments based on iron oxide.

According to manufacturing technology, the sand filler must be dry and homogeneous. High-quality products are obtained only from alluvial sand.Then no voids will form inside it, leading to a decrease in the strength and water resistance of the well parts.

A polymer sand well is a prefabricated structure of several elements that can be easily and quickly assembled into a single structure of the required depth

Some unscrupulous manufacturers use instead a sifted quarry analogue that has not undergone pre-washing. As a result, after a couple of months, cavities, voids, or simply holes are formed in the polymer sand product - these are lumps of clay rocks falling out of the plastic.

With high humidity of the feedstock, not only the cost of moisture evaporation increases, but also the strength and moisture resistance of the material decreases. It is no longer as durable, frost-resistant and resistant to water.

However, when purchasing, it is almost impossible to identify low-quality products by eye. Here you have to completely rely on the honesty of the manufacturer.

Polymer sand prefabricated wells are used in laying underground communications, used in the construction of inspection wells and septic tanks

Dyes are added to the product at the stage of preparing the mixture and baked with it during the hot pressing process. They become part of the overall molecular structure of the material.

Therefore, even hatches made of polymer sand, which are constantly exposed to the sun, do not fade and do not require touch-up.

Characteristics of polymer-sand products

The sand filler used in the production of the mixture accounts for about 75–80% of the total mass. It is responsible for the rigidity of the product. The rest is a binder polymer and dye. Polymer components bind the sand into a durable, almost waterproof monolith.

As a result of hot pressing, a product is obtained that is quite light, durable, strong and resistant to aggressive environments.

The technical characteristics of polymer-sand well parts are superior to those of concrete analogues in terms of strength and frost resistance

Products made from polymer sand are more durable and water-resistant than concrete competitors. They can easily tolerate temperatures down to minus 70 Celsius. And can withstand up to 500 freeze/thaw cycles.

At the same time, the polymer-sand composite is resistant to chemicals. It is not afraid of the aggressive environment of sewage. And when flushing the well, you can use any detergents for both household and industrial purposes.

Features of operation

Structurally, the well is a vertically buried hydraulic structure.During operation, it is exposed to groundwater and wastewater, as well as temperature changes during the winter seasons of soil freezing and subsequent thawing.

The material used to make it must be highly resistant to these factors, otherwise the tightness of the tank will be called into question.

Polymer sand wells differ in the diameter of the inner rings and hatch. These elements are quite durable, but if holes appear, they will be difficult to repair. The best option in this case is to completely replace the leaky part.

On the one hand, polymer-sand well structures are cheap and easy to assemble, and on the other hand, their individual parts cannot be repaired. If holes appear in the walls, the rings will have to be replaced. And to do this, it will be necessary to dig up the well to the level of damage and re-arrange its elements.

Thanks to the tongue-and-groove system, the rings are connected as tightly as possible, and for reliable sealing it is enough to coat them with silicone

Manufacturers promise up to half a century of operation of products made from polymer sand and perfect tightness of the joints of the rings. Tightness is ensured by a groove along the edge of all elements of the well, which prevent the rings from moving apart when the soil moves.

Another significant advantage of the tongue-and-groove lock at the ends of the rings is that when assembling the well, verticality is spontaneously maintained.

A negative nuance is the flexibility of the polymer base to mechanical influences. If you use hard scrapers when cleaning a well and use excessive diligence, you can damage the polymer walls, and as a result, reduce the water-repellent qualities of the underground structure.

Where are polymer-sand tanks used?

Well structures made of composites can be found on highways, industrial sites and private estates.

They apply:

1. When organizing storm drainage for drainage well installations And manholes for drainage.
2. As septic tanks for storing sewage waste.
3. When constructing wells with industrial water.
4. As sealed walls during construction borehole caisson.

Sealed structures are assembled from individual polymer-sand rings mainly for the accumulation and removal of wastewater.

They perfectly retain sewage waste inside, do not react to the aggressiveness of such an environment, and perfectly prevent the penetration of liquids outside the sewer system.

Construction of a standard well made of polymer-sand composite

The well polymer-sand structure consists of several modules:

1. Bottom (round base part).
2. Rings in the required number of pieces.
3. Neck tapering upward.
4. Luke.

Most often, parts with a diameter of 850, 1000, 1100 mm are found on sale. But everything here depends on the manufacturer and the purpose of the design. There are no strict state standards in this matter yet; all products are produced according to specifications.

You can make a well of almost any depth from polymer sand. It is enough to collect the required number of rings and connect them together. You just need to correctly select the thickness of the walls so that they can withstand the weight of the structure from above.

A prefabricated polymer sand well is a construction set consisting of four types of elements that simply need to be assembled in the required sequence. The depth is set by installing the required number of row rings (click to enlarge)

The base has a thickness of 4.5 - 5 cm, and the ring is available in a height of 20 cm. The hatch and neck in the form of a truncated cone come in different sizes.All parts have a protrusion (“ridge”) and a groove (“groove”), allowing you to quickly and hermetically connect the parts into a monolithic structure.

Polymer sand hatches differ in the type of load:

• Lungs (withstands up to 3 tons). They are used for the construction of inspection and drinking wells in private residential areas, as well as in green areas.
• Average (can withstand up to 5–6 tons). Used in parks, on sidewalks and small parking lots for passenger cars.
• Heavy (withstands up to 12 tons). Designed for roads and residential areas in cities.
• Super heavy (do not collapse even under loads of 25 tons).

The price from different manufacturers and in different regions varies over a fairly wide range. But on average, a ready-made set of polymer-sand well three meters high will cost 25,000–28,000 rubles.

Composite hatches are available without a locking mechanism, with threaded fittings (secret bolt) or a flag or expansion latch.

Polymer-sand prefabricated wells can last about a hundred years. During the specified period, like reinforced concrete structures, they will not lose the tightness of the joints

For private households, the first option is suitable, but in a park or on the sidewalk it is better to close the well with a polymer-sand hatch with a reliable lock, otherwise it may simply be carried away.

It will not be possible to sell a plastic product for metal, but our compatriots are able to adapt any item to their household. It's better to play it safe.

We examined in more detail the features of polymer sewer manholes In this article.

Advantages and disadvantages of such a well

Among the advantages of polymer sand wells it is worth mentioning:

1. Low weight of individual parts and the entire structure.
2. Ease of installation work.
3. Possibility to make structures of any depth.
4. Resistance of the polymer composite to moisture, frost and wastewater.
5. Easy to connect the sewer pipe inlet from the house.
6. Guaranteed service life of 50 years.
7. Environmental safety of the material.
8. Advantage in price among analogues (in terms of total costs for consumables and installation).

Composite material made of plastic and sand is not afraid of salts, acids and alkalis contained in sewage and soil. It can easily withstand continuous exposure to water, soil heaving in winter, and sudden frosts.

Some manufacturers claim a hundred years of operation without major repairs. But who checked this? Too little time has passed since they appeared on sale.

The polymer-sand composite is two times lighter than concrete. Wells are produced in the form of narrow rings weighing up to 60 kg, so when installing the structure there is no need to use construction lifting equipment

A ring made of polymer sand weighs about 50–60 kg, and its diameter is slightly more than a meter. It can be transported in the back of a Gazelle, and even one person can handle loading/unloading.

When installing a polymer sand well, there is no need to use lifting equipment. To install the elements into a dug hole, just a couple of workers and ropes are enough.

The same cannot be said about the reinforced concrete analogue. We recommend that you familiarize yourself with the installation features in more detail. septic tank made of reinforced concrete rings.

The assembly diagram of a polymer-sand well involves sequential laying of the bottom, rings and neck

The only significant drawback of a well structure made from the composite in question is the inability of the material to withstand heavy loads if the cover and thickness of the rings are chosen incorrectly. If you put a truck on a light hatch, the first one will inevitably crack.

The same situation with rings. If you place products with thin walls at the very bottom, and the well itself is made very deep, then it will not last long. The bottom row will simply collapse under the mass above. No tricks in the form of supports and reinforcements will help here.

Standard installation technology

Work can be performed both in summer and in winter. There should be a minimum of difficulties with assembling parts. Only digging in frozen soil can cause problems. The main thing is that the sealant used allows operation at the existing outdoor air temperature.

Installation is carried out in five stages:

1. Unloading composite parts.
2. Digging a pit.
3. Assembling a “constructor” from polymer-sand segments.
4. Pipeline connection.
5. Backfilling of soil.

It’s simple; you can do the job yourself without hiring hired workers. It is important to correctly calculate the required number of rings or carefully follow the project.

Stage #1 - preparation of parts and excavation work

The heaviest element of the well weighs no more than 60 kg. To unload the car, the efforts of a couple of people will be enough. At the same time, the weight of the entire structure will not exceed a couple of tons; one Gazelle will be enough to transport it from the store.

Despite the high strength characteristics, the rings should be covered with boards during transportation and storage. It is better to place the bottom on a pallet or wooden platform.

You will have to dig a hole 120–130 cm wide for a polymer sand well. The outer diameter of the rings does not exceed 110 cm. Ten centimeters on the sides is enough to lower the parts into the dug shaft.

To make drainage, you can not only remove the bottom, but also drill additional holes in the lower rings

If the well is made without a bottom, then a gradual excavation of the earth under the lower ring is possible. But with such digging, the pit will have to be dug wider, otherwise it will be inconvenient to work with a shovel. Whether it is worth doing extra work, removing one and a half to two times more soil, is up to the excavator to decide.

Stage #2 - laying sections and inserting pipes

The assembly of well rings can be done both in the pit itself and next to the subsequent descent down of the whole or part of the structure at once. In any case, you can get by with two people. But when lowering an already assembled well into a pit, you will need a tripod with a winch or a crane.

The bottom or starting ring is placed on a sand cushion 15–20 cm thick, previously poured and compacted at the bottom of the pit.

Next, the groove in them is filled with sealant or bitumen mastic and the next part is inserted into it with a comb. So all the other rings are laid one after another, and the neck is installed on top.

To insert pipes into the rings of a polymer-sand well, it is enough to use a drill with a crown of the required size

Polymer sand is quite easy to process. Holes in it for pipeline entries can be made without the use of powerful tools. An ordinary drill with a regular bit for concrete or ceramics is enough. Plus, after such drilling, the edges do not need to be ground or processed in any other way.

To seal the joint between the pipe and the wall, it will be enough to insert a rubber cuff into the hole.

Stage #3 - connecting pipes and checking leaks

After installing the polymer-sand well in its place in the pit, the sewer pipes are connected. To find out more information on installing external sewer pipes, go to via this link.

Then the tightness of the joints is checked, for which water is poured into the resulting container. If leaks are not noticeable, then all that remains is to fill the gap between the walls of the pit and the well structure.

The need for a layer of insulation depends on the region of residence of the owner. So, in conditions of moderate winter temperatures, it is enough to simply fill the gap between the walls of the pit and the assembled well

The polymer sand well material does not require insulation. But in cold regions, it is still recommended to install a heat insulator in the form of foam plastic, otherwise the liquid inside will freeze. Here you need to be guided by the design of the sewer or stormwater system, of which the assembled structure is a part.

If the polymer-sand type of well is not suitable for you, we suggest that you read the instructions for installation of sewer wells from other materials.

Conclusions and useful video on the topic

Answers to frequently asked questions about such wells:

Nuances of installing a polymer-sand well:

Advantages and disadvantages of polymer composite products:

A prefabricated well, the sections of which are made of a polymer-sand composite, has many advantages over its counterparts made of other materials. It is resistant to various negative factors, durable and quite cheap.

This is an excellent option for forming inspection shafts when laying cable lines and septic tank chambers. But when purchasing polymer sand products for constructing a drinking well, you should look at the certificates. Not all products are applicable in this case.

Have you assembled a well from polymer sand rings at your dacha with your own hands? Tell us, did you need helpers during assembly and installation, or did you cope with all the work alone?

Or maybe you are just planning the construction of this type of well and you still have questions after reading the article? Ask them in the comments block below.