Liquid glass for manhole: waterproofing of concrete rings and sealing of joints

Q: How to dilute liquid glass for waterproofing a well?

Proportions depend on the task. Approximately for the first impregnation layer, the concentrate is diluted with water about 1:3, so that it penetrates deeper into the pores of the concrete, and for the second, more dense layer of the coating — about 1:2. To seal the joints, liquid glass is added to the hardening water of the cement-sand mortar. These are indicative values — check the exact proportions according to the ETIZ instructions and the condition of the concrete.

Concrete well rings eventually begin to pass water: horizontal joints between the rings, microcracks in the concrete body and the places where soil lenses enter the shaft suffer. Surface and melt water, carrying silt, sand and pollution, enters the well, and the water itself becomes turbid. Liquid glass for well — inexpensive and proven material for internal waterproofing: sodium silicate fills the capillaries of concrete, "seals" the pores and turns the porous surface of the rings into a dense water-repellent layer.

What liquid glass is and why it works in a well

Liquid glass is a concentrated aqueous solution of sodium silicate (Na₂O·nSiO₂). Upon contact with air, carbon dioxide and the mineral surface of the concrete, the solution gradually loses water and crystallizes, forming an insoluble silicate gel. It is this gel that gives a waterproofing effect: it grows into the pores of cement stone and physically blocks the path of capillary moisture.

For a well, several properties of sodium liquid glass are important at once:

Waterproofing — fills pores and microcracks, cuts off the capillary suction of groundwater through the walls of the rings.
Strengthening and dedusting of concrete — the surface of the rings becomes denser and less "dusty", crumbles.
Antiseptic effect — silicate inhibits the development of mold, fungus and mucous fouling on wet concrete.
Chemical stability — increased resistance of concrete to aggressive groundwater.

The product of ETHYZ is precisely sodium liquid glass, a universal composition for construction and waterproofing. Sodium liquid glass is standardized according to GOST 13078; the exact values of the silicate module and density are indicated in the passport for a particular batch. Approximately, sodium liquid glass is characterized by a silicate module of the order of 2.6-3.4 and a density of about 1.4 g/cm³, but it is necessary to rely on the data of the ETIZ passport, and not on averaged figures.

Is liquid glass safe for drinking water

This is the main question that is asked before processing the well. By itself, the liquid sodium silicate concentrate has an alkaline reaction, so a fresh, unsettled solution should not get into the water. However, after application and complete polymerization, the silicate turns into an inert mineral glass, close in nature to ordinary silica. Such a solidified coating is chemically stable and does not emit harmful substances into the water.

The practical rule is simple: the treatment is carried out on dried rings, the coating is given to fully gain strength, and then the well is washed several times — the first incoming water is pumped out until it becomes clean and tasteless. Only after that the water is used for drinking. If the well is the only source of drinking water, it is reasonable to take the water for laboratory analysis before commissioning.

Where and how liquid glass is used in the well

Silicate is used in three main scenarios, which are usually combined.

1. Sealing of joints between rings

The joints of the rings are the most vulnerable place. The seam is cut, cleaned of dirt and loose concrete, and then filled with a repair composition based on liquid glass: the cement-sand mixture is closed not with pure water, but with water with the addition of liquid glass. Such a solution quickly sets and creates a waterproof plug in the seam.

2. Membrane waterproofing of walls

The inner surface of the rings is primed with diluted liquid glass, and then, if necessary, a second, more dense layer is applied. The coating fills the pores of the concrete over the entire area and reduces the capillary suction of moisture through the ring body.

3. Additive in concrete and repair mortar

When casting a new bottom slab, installing a screed on the bottom or repairing large chips, liquid glass is introduced into concrete as an additive — this increases water resistance and speeds up the gain of strength. For a drinking well, the dosage is kept moderate so as not to make the concrete excessively brittle.

Proportions and method of application

The exact proportions depend on the task and condition of the concrete, so the figures below are indicative, specify according to the instructions of ETIZ and according to your task.

Purpose	Indicative dilution	Comment
Primer-impregnation of walls (1st layer)	liquid glass : water ≈ 1:3	the liquid composition penetrates deeper into the pores
Membrane waterproofing (2nd layer)	≈ 1:2	a denser layer on top of the impregnation
Suture mortar	liquid glass is added to the hardening water of the cement-sand mixture	work in small portions — quickly grasps
Bottom slab concrete additive	a small fraction of the cement mass	moderately, so as not to lose strength

Well shaft work procedure:

Pump out the water and allow the rings to dry — the treatment is carried out on wet, but not wet concrete.
Clean the walls of sludge, plaque and loose concrete; sew and rinse the joints.
Fill the joints with repair solution with liquid glass, working in small areas.
Apply the first, diluted layer of impregnation with a brush or roller over the entire surface of the rings.
After the initial set, apply a second, denser coat.
Allow the coating to fully gain strength, then rinse the well several times, pumping out the water until clean.

You can choose a sodium liquid glass in a convenient packaging in catalogue of liquid glass ETHYZ: the composition is supplied in cans of 5 l (7 kg) and 10 l (14 kg), which is usually enough to handle a typical well shaft.

Important operating precautions

Liquid glass — material demanding for accuracy:

Quickly grasps. Dilute and apply the composition in small portions, treat in sections, do not immediately prepare a large bucket of solution.
In its pure form, it gives a fragile film. For load-bearing repairs, the silicate is used not "solo", but in conjunction with cement-sand mortar.
Alkaline concentrate. Wear gloves and safety goggles, take care of your eyes and skin; rinse the instrument with water immediately, before solidifying.
Flushing is mandatory. Potable water is taken only after complete polymerization of the coating and several pumping cycles.

And again about the terminology: liquid glass is precisely a silicate liquid, a concentrate for waterproofing and impregnation. It should not be confused with sheet and insulation materials; the well requires a fluid silicate mortar that penetrates the pores of the concrete and seals the joints. For more information about the product and packaging options, see section "Liquid glass" on the ETIZ website.

FAQs

Is the liquid glass safe for drinking water in the well?

Fresh sodium silicate concentrate has an alkaline reaction, so it should not get into the water. But after complete setting, the coating turns into an inert mineral glass, close to silica, and does not emit harmful substances. The treatment is carried out on dried rings, the coating is allowed to gain strength, then the well is washed several times, pumping out the first water to clean. For a single source, water should be analyzed before use.

How to dilute the liquid glass for waterproofing the well?

The proportions depend on the task. Approximately for the first impregnation layer, the concentrate is diluted with water about 1:3, so that it penetrates deeper into the pores of the concrete, and for the second, more dense layer of the coating — about 1:2. To seal the joints, liquid glass is added to the hardening water of the cement-sand mortar. These are approximate values — check the exact proportions according to the ETIZ instruction and the condition of the concrete.

Is it possible to seal the leakage in the joints between the rings with liquid glass?

Yes, this is one of the main applications. The seam is cut, cleaned of dirt and loose concrete, washed, and then filled with cement-sand mortar sealed with water with liquid glass. Such a composition quickly sets and forms a waterproof plug in the joint. You need to work in small areas, because the liquid glass sets very quickly.

How much liquid glass do you need per well?

The flow rate depends on the area of the rings, the porosity of the concrete and the number of layers. For reference: liquid glass ETIZ is supplied in cans of 5 l (7 kg) and 10 l (14 kg), and there is usually enough for processing a typical well shaft, taking into account impregnation in 1–2 layers and sealing of joints. It is better to calculate the exact flow rate according to the surface area and recommendations in the composition data sheet.

How does sodium liquid glass differ from potassium for a well?

ETIZ produces sodium liquid glass — a universal composition for the construction, waterproofing and strengthening of concrete, and it is used for the processing of well rings. Potassium liquid glass is another product that is more often used in paints and flame retardants. To waterproof the concrete shaft of the well, focus on sodium silicate.