Insulation of the entrance metal door: an overview of effective methods, step by step instructions, photos

The fashion for reinforced steel doors to enter a house or apartment has a downside. Any metal has a high thermal conductivity, so in winter a large amount of heat escapes through the doorway.

What causes heat loss through doors?

This is not to say that manufacturing companies are unaware of the existing problem. Usually, for a metal door, the outer (front) plane is made with an overlap (overlap) on the gap between the leaf and the frame. In addition, the door leaf itself must be made thick in order to put an additional layer of thermal insulation into it. But all this helps only partly.

The main causes of heat loss:

1. The presence of a cold draft in the gaps between the box and the door leaf. Slots always appear during operation, and regardless of the design of suspensions and hinges.
2. Incorrect installation of the door frame in the wall opening. The box is always made of stamped steel without thermal insulation inside the supporting profile.
3. Insufficient insulation layer inside the door leaf.

Most inexpensive metal doors may not have door leaf insulation at all. Internal ribs and a reinforcing profile, the presence of crossbars, a specific scheme for blocking the door leaf inside the box with closed locks can interfere.

Reading: How to properly insulate the front wooden door with your own hands

How to find the place of penetration of cold

Before trying to put insulation on a metal door, you need to determine the location of problem areas. It is best to start with a doorway. If a metal door has been standing for more than 5 years and is actively used, then most likely the first cold bridge is connected with the opening.

Checking the doorway

After 3-5 years of service, the geometry of the doorway changes. The problem with any metal door is that under the weight of a heavy door leaf, the hinges are deformed, as well as partially the box itself. As a result, gaps appear between the box and the canvas. Almost always, the largest of them are located at the top of the doorway.

You can see places with a loose fit if you highlight the metal door with a regular flashlight. In those areas where the insulation fits snugly against the box, it will be dark, there will also be areas with light stripes. In these places, heat leakage occurs due to drafts.

Checking the canvas

The main enemy of the entrance is not only severe frost. If the front door goes directly to the street, then the bridges of cold can be seen with your own eyes at the first severe frost. Ice frost is formed due to freezing water vapor, therefore, in addition to insulation, you need to do a vapor barrier.

The coldest frozen places can be determined visually or by hand. If there is no frost outside, then it is better to use a remote infrared thermometer. Typically, the leakage area is the perimeter of the door leaf, as well as the floor and side posts of the box.

Checking the box

At the metal entrance door, not armored, the door frame is made of a hollow profile. Only in some modifications with increased fire resistance and sound insulation, the profile is filled with foam or glass granules.

But since, according to the instructions, the box of the entrance metal door should be filled after the wall is installed in the opening, then, most likely, they remained empty. Masters usually do not want to backfill.

But, oddly enough, the presence or absence of insulation inside the profile does not affect heat loss in any way. The problem is that the outer parts of the steel profile easily lose heat due to the high thermal conductivity of the metal walls. That is, the profile will lose heat until insulation is laid on the inside or outside of the door.

What heater to choose?

The type of material is selected depending on the method of insulation. If we are talking about improving thermal insulation without dismantling the door leaf, then it is quite possible to use foil polyethylene foam, sheet polystyrene foam, penoplex and even isolon. Often use minvolokno in rolls.

Thermal insulation of the box

The metal frame is assembled by welding at the factory, the thin-walled profile is manually welded by a carbon dioxide semiautomatic device into a box. Moreover, the assembly is carried out in special devices - conductors, thanks to which it is possible to avoid deformation of the box (torsion by the "propeller"). Therefore, the box comes from the factory complete with a metal door. And it is also installed together with the door inside the wall opening.

This means that it is impossible to cut or disassemble the box just to put insulation inside. The metal box after installation must remain in place in any situation.

But up to 25-30% of all escaping heat is lost through the box, so you can’t do without insulation. In this case, a layer of insulation, usually foam or polystyrene, is laid on top of the metal profile of the box.

Warming can be done in two ways:

• fix the foam strips over only the metal box (along the perimeter;
• make complete insulation, that is, lay the thermal insulation simultaneously on the steel profile with an overlap on the wall surface.

The second method is used mainly for concrete walls, as well as metal entrance doors of private houses. For apartments, this scheme is used less frequently, since it is required to cut off part of the wall under the casing. Therefore, the owners are usually limited to insulation using foam, laid on a metal profile under a decorative casing.

We repair the opening

For apartments of high-rise buildings, it is quite rare to restore the opening. Even in severe frosts, the positive temperature and low air humidity remain inside the entrance. Therefore, the walls do not collapse. All that needs to be done is to remove the trim from the side of the landing and blow out all the free space between the box and the wall surface with mounting foam.

For private houses, the situation is completely different. Installing an entrance metal door requires a fairly large opening in the wall. Usually, the width, taking into account the thickness of the door frame, is at least one meter. Plus a height of about 200-210 cm.

The amount of work is huge, the thickness of the walls in the area of ​​​​the entrance group is rarely less than 30-40 cm. In private houses, the opening is laid out of brick according to pre-calibrated dimensions of the future front door.

It is clear that no additional edge insulation is done when installing a metal door frame. The problem is noticed already after the installation of the front door, when the facing brick or wall material begins to crumble due to freezing condensate.

Therefore, before insulating the front door, you need to repair the opening in the wall.

Along the contour of the opening in the wall, a grinder and a perforator cut off a small layer of material up to 20 mm thick. You need to cut the brick from the surface of the opening from the inside and outside;

The door panel will need to be removed. If, after trimming the opening, the walls along the contour of the anchor continue to normally hold the exit door frame, then no additional measures will be required. Otherwise, you will have to replace the anchor bolts (studs) with longer and more massive ones.

Next, you need to disassemble and remove the invoice metal threshold. Usually the entrance metal door is installed on an oak board 40 mm thick. It serves as both shock absorber and insulation. If the tree is in good condition, then it will be necessary to cut a groove 20-30 mm deep in the board, additional insulation in the form of a strip of foam plastic will be laid in it.

But if the entrance metal door was simply placed on a concrete screed lined with fiberglass, then the concrete will need to be cut with a perforator to a depth of at least 80 mm. Under the threshold, a groove (strobe) should be obtained for the entire width of the opening in the wall. The height of the strobe is at least 40 mm, the depth is 80 mm.

Now it will be necessary to lay foam 20 mm thick on the grooved surfaces, 40 mm under the threshold. On the side walls and under the ceiling, insulation is laid on the ends of the opening both from the inside of the room and from the outside. Insulation can be fixed with glue and fungi. Mounting foam, as a rule, squeezes out the insulation, so you still have to fix the foam with mechanical fasteners.

The laid insulation will need to be plastered, otherwise the solar ultraviolet and moisture will destroy the polystyrene foam in a few years.

Insulation of a metal door leaf - instructions

First of all, the front door must be removed from its hinges and laid on a workbench or carpentry table. You can lay the insulation, as they say, on weight without removing the canvas, as in the photo.

But this method can be recommended only for garage doors and entrance groups of utility rooms. The reason is that polystyrene is not the best option for insulating metal doors.

What will be needed?

The set of materials depends on the size and design of the front door. For a standard Chinese door with a metal outer cladding and a plastic inner panel, you will need:

• wooden slats and bars 30x40 mm, 5-8 m long;
• fiberboard or pieces of thick cardboard;
• mounting foam;
• foam plastic 25-40 mm thick, depending on the thickness of the metal door.

If it is planned to insulate the entrance metal door of the “armor” type, then instead of expanded polystyrene or foam plastic, it is better to use rolled mineral wool and foil polyethylene foam up to 5 mm thick.

Step by step instructions

Almost all entrance metal doors of the budget level are arranged in the same way. They are made mainly in Southeast Asia and are offered as entrances to apartments. For a warm climate, perhaps there would be no problems, but in the conditions of the middle lane, the front door does not keep heat at all.

The first thing to do according to the instructions is to remove the door leaf from the hinges and lay it on a workbench (table). The most difficult thing in warming the door leaf is to disassemble it. You have to unscrew the canopies, the lock and a few screws around the perimeter.

After the metal shell was separated and removed, the back panel with paper stiffeners remained on the table.

There is no insulation and sound insulation in simple entrance metal doors. The outer metal cladding provides the main contribution to the rigidity of the door leaf, therefore all those paper ribs are there just to keep the surface of the front door from slamming under load. Therefore, all paper must be removed.

Next, an internal frame is assembled from wooden slats, you can use any tree, but larch is best suited. It is not afraid of moisture and does not rot during prolonged contact with water condensate. You can even sew up the entire canvas with larch. The front door will turn out to be very durable, but in terms of the level of thermal insulation it will become noticeably worse.

The next step is to sew up the base with a fiberboard sheet, not necessarily solid, it is enough to collect scraps and waste for insulation. But the gaps and joints must be adjusted as carefully as possible, otherwise there is a risk of condensation on the insulation layer.

Next is the insulation itself. It must be made from several whole sheets of polystyrene foam. The fewer seams between the insulation sheets, the warmer the door leaf will turn out.

Places where cracks have nevertheless formed should be filled with pieces of polystyrene foam with polyurethane foam. Now it will be necessary to check and align the plane of insulation. After installing the metal cladding, there should be no protruding sections, bumps or "humps".

It is necessary to mount the front door lock and return the metal tabs to which the door canopies were screwed.

The last stage - you need to put on the metal lining of the front door, carefully besiege it around the perimeter, attach the canopies and the padlock bar.

Due to the installed insulation and wooden frame, the weight of the front door has increased by 20%. Therefore, it may be necessary to replace the canopies with more powerful ones. After installing the door leaf on the box, you will need to stick a new seal, it is best to use tubular silicone with an additional comb. On a metal door, it practically does not wear out.

Reinforced metal door insulation

The process of laying insulation on entrance doors with a reinforced metal front panel looks a little more complicated. This is not an armored door, the metal sheet cannot be disassembled without the use of a special tool. Warming of the "armor" is carried out at the assembly stage.

Usually, the internal cavities of the front door are filled with a viscous filler. It works as insulation and soundproofing. In addition, the filler does not make it possible to work with a cutting wheel, high-speed drill or gas burner.

A standard metal door is insulated with polystyrene foam or blown out with mounting foam. Very often, inside the entrance doors, several (up to a dozen) layers of corrugated cardboard treated with water-repellent impregnation are simply laid as insulation. Such doors are mainly used as entrance doors for apartments and offices.

To lay the insulation inside the metal sheet, the door must be removed from the hinges and laid on a workbench. The weight of a metal structure can reach 80-100 kg, so dismantling is best done with one or two assistants.

The next step is to cut off the rivets and remove the back panel, it can be metal or plastic.

Before laying, it is necessary to dismantle the lock, crossbars and the remains of the old thermal insulation.

Next, a layer of foil polyethylene foam is laid on the back side of the front panel. The insulation sheet should overlap on the inner ribs and even on the end surface. This will provide reliable protection against any drafts.

After that, you can assemble the lock and install the bars in place. So that metal moving parts do not come into contact with the insulation, pipe insulation made of foam is put on top.

Now you need to lay the main insulation. Rockwoll stone wool 50 mm thick is best suited for thermal insulation of a metal sheet. Warming, if possible, should be done in one piece. The fewer seams, the lower the likelihood of cold bridges forming inside the metal front door.

Before laying, a sheet of stone wool is cut to fit the niches inside the door leaf. Insulation should be inserted into a niche with a small compressive force. This method will hold the material inside the front door better than any glue.

Now it remains only to lay the back panel of the front door and assemble the entire structure in reverse order.

Advice! Some craftsmen recommend installing the back panel with sealant to avoid the accumulation of water vapor inside the front door.

It will also be useful to put one or two bags of silica gel inside the metal sheet. It will absorb water vapor and protect metal parts from rusting.

Results

Insulating a door with your own hands in a private house is not as difficult as it might seem at first glance. Work requires accuracy when laying thermal insulation. The procedure itself is simple, but cold bridges or gaps inside the door leaf should not be allowed to remain.

For apartment entrance doors, cold spots will form in these places. For the entrance doors of a private house, a cold bridge will lead to intense condensation and rust.

Tell us about your experience with insulating front doors. What material was used for thermal insulation and why? Also save the article to bookmarks and share it on social networks.