Do-it-yourself chimney pipe insulation: instructions for work

Condensation is the main enemy of any chimney. It is formed on the inner surface of the chimney from the moisture contained in the air, as a result of the difference in temperature outside and inside the room. Condensed moisture enters the microcracks and seams of the inner surface of the chimney, when the temperature drops, it freezes, and, expanding, destroys the masonry.

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Metal chimneys also suffer greatly from condensate, because this liquid substance is nothing more than low concentration sulfuric acid. Formed on the inner surface of the metal flue, the condensate gradually renders it unusable. The only way to combat the formation of this rather aggressive liquid is to insulate the chimney pipe. It is this procedure that will eliminate the cause of the appearance of condensate on the inner surface of the chimney.

There are several basic ways to insulate chimneys. The choice of one or another method directly depends on the material from which the gas outlet paths are made. The most common in our country are brick chimneys, as well as widely used by many private developers, steel and asbestos-cement pipes.

Chimney insulation from the outside is far from the most difficult procedure in construction, and therefore such work can always be done independently, without involving professionals.

Important!
With self-insulation of the chimney, safety precautions should be strictly observed, because you will have to work at height. Particular attention should be paid to shoes, which should be comfortable and have non-slip soles.

Brick chimney insulation

There are three simplest ways to insulate a brick chimney that you can do yourself:

1. Plastering. This method consists in applying several layers of a special mortar to the outer surface of the brick chimney. With the advent of modern thermal insulation materials on the construction market, this method is considered the most inefficient and most labor-intensive.
2. Backfill. This technique involves the manufacture of fixed formwork around the chimney. The space between the formwork and the brick pipe is filled with heat-insulating material, which is special granules of various sizes. Most private developers who choose this method of insulation use brick, slag or expanded clay as a heat insulator.
3. Mounting on the chimney of basalt wool or fiberglass insulation, followed by sheathing or the creation of an additional casing. This method is considered the most effective, therefore it is widely used by professionals for the insulation of brick chimneys.

Method of work: plastering

• Previously, a reinforcing mesh is fixed on the pipe, and a plaster mortar is prepared, consisting of sifted slag, cement, lime and water, in a ratio of 3: 1: 2. The amount of water is selected independently. The solution should lie well on the prepared base, not drain or fall off it.
• After all the preparations, the first layer of the solution is applied to the reinforcing mesh, 2-3 cm thick.

Advice.
Subsequent layers of the plaster mixture can be applied only after the previous ones have completely dried.

• After applying the last layer, the surface of the plaster should be leveled for subsequent painting. If, after drying, cracks appear on the surface, then they need to be puttied, and the surface should be carefully rubbed.
• Paint the pipe with chalk or lime mortar.

Insulation of chimneys with glass wool or mineral wool materials

In order to independently carry out work on the insulation of a brick chimney with these materials, you will need: U-shaped profile, vapor barrier, corrugated board. As a heater, it is best to use mats made of basalt fiber or glass wool, 50–100 mm thick.

• First of all, the brick surface should be prepared by cleaning it from protruding cement mortar, repairing cracks, etc.
• After, a frame is assembled from metal profiles. The upper rail should be attached directly to the masonry, and the lower one to the roof.
• The next step will be the fastening of vertical profiles. The vertical racks should be fixed in such a way that the insulation of the required thickness can be easily laid in the resulting crate.
• The joints of the insulation material should be fixed with adhesive tape, and the insulation itself, using special plastic dowels, to the masonry.
• After that, the resulting structure should be wrapped with a vapor barrier film.
• The last stage in the insulation is the sheathing of the resulting structure with corrugated board, fixing it on the crate using self-tapping screws.

The above methods can be combined by fixing insulation on a brick pipe and plastering it with several layers of cement mortar.

Do-it-yourself insulation of the chimney pipe will significantly reduce the heat loss of the house heating system and reliably protect the brick chimney from the formation of condensate on its internal surfaces.

Thermal insulation of asbestos-cement chimneys

Insulating your own chimney from an asbestos-cement pipe will not be difficult for any home master. This will require: pliers, knitting wire, galvanized sheet, rolled basalt insulation or glass wool insulation.

• The protruding part of the asbestos pipe should be wrapped with insulation in several layers, carefully fixing it with wire on the chimney.
• After that, wrap the resulting structure with a sheet of galvanized metal, securing it with wire.
• Fill the space between the metal and the pipe, at the head of the chimney, with a strong cement mortar to prevent moisture from entering the insulation.

This is the simplest and cheapest way to protect an asbestos-cement pipe from weather conditions and prevent condensation from appearing in the chimney.

Thermal insulation of steel chimneys

For independent work, you will need: a pipe of a larger diameter, material for insulation, with good thermal insulation properties and incombustibility indicators. To date, most foreign and domestic companies producing heaters offer a special material made in the form of semi-cylinders. Such a heater is ideal for thermal insulation of steel chimneys of circular cross section.

• First of all, you should choose a metal pipe of a suitable diameter so that the distance between its inner wall and the chimney is at least 5 cm.
• After that, you should put on a section of a pipe of a larger diameter on the gas outlet, and tightly fill the space between them with a heater.

Advice.
For the convenience of performing work, this procedure should be performed step by step, connecting the prepared sections of the chimney to each other.

All the methods of chimney insulation presented above are quite simple, but if you feel it is difficult to perform this or that method of insulation, then do not risk it and contact professionals who will do this work quickly and efficiently.