Waterproofing manholes: means and methods

One of the most common ways of devices Private home sewer system is the construction of a concrete septic tank. In this case, not everyone asks its tightness.

And in vain, because the correct waterproofing manholes not only prolong their life, but will prevent the soil from pollution. Let's see why you need to seal the drains and how to do it.

Why seal the cesspit?

Serious mistake made by those who believe that we can neglect the work associated with sealing the manhole.

At best, there will be severe pollution of groundwater, and at worst - septic tank of concrete rings collapse in a few years.

There are several reasons because of which can not be neglected waterproofing well, this:

1. Corrosion of the reinforcing component w / w rings. As a result, the formation of rust lesions on the reinforcement elements is significantly reduced load bearing capacity of the well shaft, which is constantly subjected to pressure accommodating its soil.
2. The weakening of the concrete walls of the mine. Sewage and Groundwater contain chemically aggressive substances, negatively influencing the concrete structure. Over time, under the influence of their shells are formed and cracks that lead to the destruction of concrete.
3. The probability of wastewater infiltration. The walls of the concrete shaft with cavities and cracks will not prevent sewage infiltration into the surrounding soil. Which will eventually lead to critical changes in the ecological balance.
4. Depressurization joints. concrete absorbed water on a freezing period will be slightly increased in size. Visually imperceptible "progress" concrete rings will become a serious threat to the assembled joints are mine.
5. destruction of concrete. Freezing binder component of concrete blocks at subzero temperatures, especially in seasonal freezing of soil zone causes rapid disruption of communications in a monolithic array. For this reason, the well will last two to three times less than the due date.

If a protective waterproofing properties, everything is clear, there is another important reason for sealing manhole. We are talking about floods and groundwater, the level of which in the period of active snowmelt and heavy rains it becomes significantly higher.

Flood and ground water can cause premature filling of the well because waterproofing concrete without water is able to pass. As a result, it will have to pump with the use of specialized equipment.

Work on the insulation of sewage wells can be divided into two main types:

• Internal waterproofing;
• Exterior waterproofing.

To simultaneously perform internal and external waterproofing, which will maximally protect the well walls from erosion, and soil and groundwater - pollution.

on the outer insulation work

The main objective of such waterproofing is reduced to minimize or eliminate contact with the outer walls of the septic tank by groundwater.

It is best to carry out the work on the stage of the construction of the well. If this is not done in time, then you have to perform a significant amount of earthworks.

Waterproofing bituminous materials

For outdoor use waterproofing bituminous mastics and asphalt roll materials:

1. On the cleaned and prepared surface must be applied to the composition of 3 parts gasoline to 1 part of bitumen. Apply the mixture to be via the compressor by spraying, but can confine and conventional brush.
2. For maximum sealing seams should be glue-bentonite rubber tape.
3. After drying of the primer layer is necessary to perform the preparation of concrete rings - chipped and repaired potholes to form a flat surface. To fill the shells is best to use a mixture of PVAc with a cement-sand mortar in a ratio of 1 to 5, but can confine and conventional cement slurry.
4. After drying of cement necessary to put another 1 undercoat layer of bitumen-gasoline mixture, but in the proportion of 1 to 1.
5. The next step is the application of mastic, it is better to use gudronovuyu mastic, since bitumen is easily peeled off. It is also possible to apply the bituminous mastic obmazochnye with polymer additives.
6. It remains to apply 3-4 coats of roll materials (roofing material), carefully prokleivaya joints.
7. Upon completion of the work necessary to make the backfill soil, arrange the clay lock and concrete blind area, if necessary.

The main advantage of waterproofing bituminous materials well are simplicity and low cost of work material. In this implementation technology works should adhere well, because the proportion of a violation bitumen-gasoline mixture can cause premature failure of the protective layer.

The use of penetrating impregnation

Waterproofing of penetrate action is a good alternative to bituminous materials. However, for its use requires a careful preparation of the concrete surface with the elimination of irregularities and grinding.

In this case, polishing is best done by sandblasting method, which will reveal the most pores of the concrete.

After polishing the concrete coating is not performed. Before applying the deep penetration of the waterproofing should be well to moisten the surface.

It is best to give preference to proven primer "Penetron", "Kalmatron", "KtTron," but we can restrict more and cheaper alternatives such as "Elakor-PU."

Waterproofing must be applied with a sponge or a brush with a stiff brush. the composition of the drying time is three days. In this case, the drying process must be done to avoid moisture surface cracking, and in hot weather need to perform humidification every 3-4 hours.

After drying the first layer should be applied to another layer of waterproofing. Smears can be performed with a brush or spatula, they should be directed perpendicular to the previous strokes. It is important to make sure that during the solidification of the surface is not subjected to mechanical damage and drying out.

Plaster under pressure

When gunning cement surface of concrete rings requires no preparation. Using cement-gun, providing a minimum pressure of 4 atmospheres, a layer 5-10 mm thick cement. A high pressure provides maximum sealing cement and a decrease in its porosity.

The cement coating needs periodic wetting (3-4 hours in hot weather and 10-12 hours under normal conditions). After 10-12 days spraying should be repeated and apply another layer of cement.

Construction of clay castle

If you are unable to hold the upper insulation rings manhole costly means fit the usual pug. The principle of concrete walls to protect the device is similar to the arrangement of drinking water wells clay castles.

Only a layer of clay is placed in a narrow trench around the mine, because it drains to protect from rain and flood water is not necessary.

Clay Castle is best done in spring in warm dry weather. You can use the clay that was extracted when the device well. Thus it is necessary to remove impurities and residues of sand stones.

The first step is to release the area around the ring thickness of 20-25 cm to a depth of about 2 m. Initially necessary to fill the resulting gap wet and oily clay carefully tamping it.

Next, remove the layer of soil 30 cm thick in a radius of 1.2 m from the ring wall. The resulting space is necessary to fill in the clay layers, stacking its layers of 8-10 cm. Each of the stacked layers should be well compacted. The resulting clay locking minimizes contact with the external walls of the well floodwater and precipitation.

A few years later, when the soil compacted and maximum prosyadet, you can begin installation of concrete blind area. This will require formwork to produce backfill cement-gravel mixture in a ratio of 1 to 10.

The thickness of the filling should be 0.1-0.15 m, it should be well sealed. It remains to be prepared to make concrete and fill.

Internal waterproofing well

The following materials can be used for interior waterproofing:

• cement plaster;
• bitumen petrol mastic or molten bitumen;
• cement-polymer composition;
• bitumen-polymer mixture;
• polymer waterproofing.

Inner waterproofing manhole can be produced shortly before his operation.

Before carrying out waterproofing work well must be dried. The concrete surface should be cleaned of dirt and dust, if necessary - to make grinding.

Cracks and crevices joints must be expanded to 20-30 mm, with a brush to clean metal and seal the cement-polymer mixture.

Waterproofing cement mixture

For waterproofing septic best applied finished mixture, which sufficiently dissolve water in accordance with the instruction. The resulting formulation must be applied with a spatula for 2-3 times so as to form a layer 6-8 mm thick.

After applying the last layer of the surface is necessary to moisten and well close the lid. Depending on the temperature of the drying of the waterproofing layer may be 4-5 days.

In the open pit and wet the inner surface during this time need 3-4 times a day. The service life of the cement of insulation up to 15 years.

In most cases, the cement mixture is applied to the insulation before applying the finishing joints waterproofing.

The use of bitumen-painted gasoline

Works are performed in the same way as in the apparatus similar exterior waterproofing. The mixture was applied in three layers, during solidification of each layer is about 12 hours. This type of waterproofing is not durable, useful life not exceeding 10 years.

If, instead of bitumen and gasoline paint two coats of bitumen mastic and roll insulation overlap, the service life can be increased threefold. It should work as carefully and ensure that ventilation well as surfacing inside associated with certain risks.

Waterproofing cement-polymer composition

Cement-penetrating polymer mixtures - one of the most modern and effective methods of waterproofing. It is best proven mixture of the Greek company ISOMAT. They are environmentally friendly and durable.

Since septic tank environmental purity is not as important as in the well, the internal waterproofing can be done cheaper and coating of penetrating "Penetron Admix" or "Penekrit". The mixture must be applied in 3 layers with a spatula. Cement-polymer waterproofing will last at least 40 years.

If used as a two-component mixture CeresitCR insulation 166, it is possible to extend the life of the waterproofing layer to 60 years. The prepared mixture should be applied to damp concrete surface without efflorescence using hand-ceiling brushes.

At first, not yet frozen layer, it is necessary to lay the reinforcing mesh and second coat mixture. CeresitCR two-component 166 has high elasticity, which reduces the risk of fracture in the sealing rings result of a small displacement or deformation.

Use of polymer mixtures

This material is the most expensive, but at the same time the most effective. Use of polymer mixtures, would be justified under unstable septic tanks, which ring strain is observed. Maximum efficiency is ensured by high elasticity is achieved by installing the membrane for special mastic.

The best thing has proved to film polymer membrane. First concrete rings must be treated with a special mastic and leave for 24 hours. The film has an adhesive basis, roll expand enough to press the film to smooth the surface and to remove air bubbles. Insulation life of the polymer membrane is 50 years old.

Use of plastic inserts

One of the most reliable and easiest ways manhole waterproofing is to use multilayer polymeric or plastic insert. It has the shape of a cylinder equipped with bottom, lid and spout. insertion height of 4.5 m, and the diameter may be 90 cm, 140 cm, 190 cm.

The thickness of the wall of the insert ranges between 8-25 mm depending on the manufacturer. To prevent deformation of the insert are amplified stiffeners. Installation is very simple, just omit plastic insert into the well and to fill the space between the insert and the walls of the concrete ring a dry sand-cement mixture.

Sealing joints between concrete rings

Whichever way have not been performed waterproofing septic tank made of concrete rings, it can not provide a complete seal without compulsory treatment of joints between the rings. Even at the stage of assembling works between the rings should pave the waterproofing, and the cushioning.

It is best to use bentonite-rubber gasket. Granules bentonite clay present in its structure, in contact with water are able to increase its volume by 3-4 times. Such a reaction clay maximizes to fill cracks and voids present between concrete manhole rings.

Bentonite-rubber gasket has a high level of ductility. This quality allows you to preserve the integrity of the septic tank, even in the case of a small displacement of concrete rings. Spend sealing seams should not only between the rings, but also for mounting the first ring on a concrete base.

You can do simple and instead of expensive bentonite-rubber gaskets to put ordinary hemp, jute or flax rope. By themselves, the rope will not provide seam sealing, so they must impregnate fibrorezinoy. Stack rope to be polymer-cement mixture, which can be replaced with a mixture of cement with PVA glue.

Conclusions and useful videos on the topic

Set the lower rings on the stove, a one-component composition treated Raber:

The device lock clay concrete around the trunk:

Installation of the plastic insert into the shaft manhole:

Whichever method is chosen for sealing manholeAll work must be performed with the maximum quality. The slightest defect can result in the destruction of the insulating layer and will inevitably lead to the necessity of re-waterproofing.

If you have already carried out work on the manhole waterproofing on your own site, tell us which method you choose, and what came of it. Perhaps you know some nuances that need to be taken into account when carrying out waterproofing work? Leave, please, comment, share tips, ask questions in a section block.