The protective function for the pipe is performed by a cap. This is an element made of metal, which is placed in the upper part of the chimney. It protects the pipe from destruction by precipitation, from the ingress of debris or birds, and also performs a decorative function. The need to install such a device is still debated. To choose the right pipe cap, you should familiarize yourself with their varieties. You can also make a protective device yourself.
The main functions of the hood
A special metal product called a cap on the chimney pipe is designed to protect the outlet from the negative effects of atmospheric conditions. It should not interfere with traction, distort the conditions of movement of air masses. The presence or absence of such an element is foreseen at the initial stages of the heating system design. Installation is carried out in accordance with GOST and industry documents.
The hood performs the following functions:
- Closing the outlet against wind blowing. The direction of the air masses is constantly changing, therefore, to prevent the appearance of reverse thrust, a protective visor is installed.
- Protection from rain and snow, mechanical pollution, birds. The visor itself protects from precipitation. To prevent the birds from getting inside, a net is placed. Over time, frozen condensation can form on it, which reduces the thrust. In addition, icicles form on the net in winter. It is necessary to pre-select a material on which moisture will not form.
- Increased head life. Since the cap protects the pipe from debris and dirt, its inner part will not be damaged. This will extend the operating time.
- Decor. Original hoods can enhance the appearance of the house and emphasize the style of the building.
When installing the hood, it is important to think over the system in such a way that the element does not interfere with the free exit of smoke. Otherwise, from the decorative visor there will only be harm and a threat to fire safety.
Despite all the functions of the hood, some specialists are against their installation. This is due to the fact that the fungus interferes with the release of combustion products. The pipe umbrella in this case reduces traction. Also, during combustion, water vapor is released, which settles on the metal. In cold weather, icicles form, which overlap the chimney section. As a result, waste can go into the house and poison the residents.
Modern round-shaped chimneys do not have a place for birds to nest. On such models, the installation of a protective copper mesh is not required. Correctly constructed chimney ducts have a condensate collector at the bottom. It receives precipitation in the form of water, which can then be removed.
Caps design
On sale you can find a large number of different models that differ in functionality, size, type of material used, external data. But they all have required elements in their design.
- The umbrella or the cap itself. In fact, this is the roof of the chimney, which performs a protective function.
- Dropper apron. Such an element is present in brick chimneys. Required to drain condensate away from the pipe. Keeps the structure dry for a long time.
- Bracket.It is necessary for lifting and holding the hood over the chimney. The number of clamps depends on the size of the shelter, its weight and design.
- Stingrays. They are installed only on complex structures. They allow you to increase the size of the product and complement its appearance.
All caps differ in appearance. Each specialist can design the design of the visor for the pipe himself, but it is recommended to start manufacturing with the creation of the simplest design. Only after calculating all the parameters and performance characteristics can you make changes to the finished device.
Varieties of protective elements
Along the cross-section of the pipe, there are:
- round;
- rectangular;
- square.
The most common designs include:
- Models in the form of houses. They have a hipped roof.
- Houses with gable roof.
- Chimneys with a semicircular and conical roof.
- Flat umbrellas.
Additional elements can be attached to the chimney cap. It can be a spark arrester, weather vane, ornaments, figurines (skates, birds) and other decorative details.
Selection recommendations
The main function of the hood is to protect the chimney, therefore, the appearance and shape can be of any kind. It is important that the product fits the pipe in size. The fungus should not interfere with ventilation and smoke removal from the room.
Usually, heads with four slopes are installed on brick pipes. It is better to put chimneys with a cone on round chimneys.
The overhangs of the umbrella should protrude a few centimeters on each side of the pipe. This will additionally protect the chimney from rain and foliage. For protection from birds, a net is placed under the umbrella. Its functions can be performed by openwork forging, which will decorate the appearance.
If your home uses a wood-burning stove, it is best not to opt for a painted chimney. The paint from it quickly fade under the influence of smoke. It is better to take the heads with a sealed double cover. Heads with a hinged lid are installed for ease of cleaning. When installing a gas boiler in the house, you can put painted caps.
Basic materials
Different metals are used to create protection for the pipe. They must be reliable, strong, not react to external influences of the environment and not reduce the pulling force. These materials include galvanized steel, stainless steel and copper.
Protection made of galvanized steel is well tolerated by aggressive environmental influences and is distinguished by its practicality. Galvanized steel does not lose color when exposed to direct sunlight. It can additionally be coated with a colored polymer - polyester. If a thin galvanized steel cap is installed, it can burn out after 3-5 years of constant use. High temperature gases destroy it, therefore it is recommended to install a reflector made of stainless steel. The cost of the device will be higher, but the service life will increase by several decades.
Higher grade materials include stainless steel. It is distinguished by its durability and high strength. Its cost is higher than that of galvanized steel. It can be used as an additional protective element of the hood.
Copper caps are considered to be the most beneficial. They have a long service life of up to 100 years. Copper combines well with gutters and other elements, and also does not lose its attractive appearance over time. It is easier and more convenient to make a hood for a chimney from copper sheets. For work, a copper sheet with a thickness of 0.5 mm is selected. It is harder to work with them than with thin ones, but the stability of the assembled structure will be higher.
Self-creation of the cap
Then you can start creating a drawing, cutting out parts and final assembly. But before you make an umbrella on a pipe with your own hands, you should calculate the size and diameter of the chimney.
Preparation of parts
First of all, it is necessary to measure the head on which the visor will be attached. The dimensions of the product should be 10 cm larger than the pipe diameter. There should be a 50 mm projection on all sides. The slope of the slopes varies from 30 ° to 45 °. The minimum height from the cut to the canopy must be 100 mm.
After measuring the dimensions, you can start creating a sketch. It must be drawn on a piece of paper. It is better to take the simplest base model and make linear adjustments to it.
Further, the details of the visor for the chimney are transferred to the copper sheet. When transferring contours, you need to leave 0.5 cm for the looping. For the convenience of work, the copper sheet can be cut into several parts and on each one you can draw your own details. You can draw on copper with a special felt-tip pen or awl. It is better to use the second option, since the lines in this case will be thinner and you will not have to remove the traces of the marker.
The marked details are easy to cut with metal scissors. If you have special equipment, you can perform cutting with plasma cutting.
Bending of parts and assembly of the cap
To bend the parts correctly, it is recommended to practice on unnecessary sheets of metal. If you have experience and skills, it is not necessary to perform training, you can immediately assemble the hood on the chimney.
Bending of parts begins with a ringing of the edges. This can be done manually or using special equipment. The quality on the machine will be better, the speed of execution is higher, but not everyone has the opportunity to buy professional tools.
After looping, the first part of the base is made. Additional bottom bend will provide high strength. The corners must be bent according to the dimensions indicated in the drawing and controlled with a protractor. If the job is done on the machine, specific templates can be selected. In this case, the bending technology will not affect the work algorithm. On the base, rolling should be done, which will add stability to the structure.
Next, the base of the cap is assembled onto a brick pipe. For work, you need special pliers. With their help, you need to separate the fastening parts in different directions and assemble the elements into a single structure.
Sliced and folded workpieces should be laid out on a flat surface. All dimensions, folds and angles must be rechecked. With the help of pliers, it is necessary to bend the limit switches and collect all the parts. It is important to carry out the work carefully, without damaging the face. The locks do not need to be closed yet, they should only be prepared.
After a thorough check, you can close the locks with the blows of a mallet. This completes the assembly of the base, you can start creating an umbrella for the chimney.
Manufacturing the roof of the hood for the chimney
The algorithm for creating a hood roof is similar to work on a base stock. In the same way, all parts from the template are transferred to the metal. It is imperative that each element has an end for a hem. Its length is chosen based on convenience. It is important to remember that the length of the top hem should be twice the length of the bottom hem. The dimensions must be selected in such a way that as little metal as possible goes to scrap. Recommended outlets on triangular slopes are 30 mm, on trapezoidal slopes 15 mm.
Blanks are cut with metal scissors. For small elements, depending on the side of the fold, a different tool is selected - left or right.
After cutting, the parts are bent. When they are ready to join, lay out the elements on the table and double-check the dimensions and angles. Stiffeners should be rolled in the middle of the plane of the copper profiled sheet and bend in the lower part. It will improve the strength and stability of the hood.
Next, the final assembly of the umbrella is performed. All connecting elements must be aligned with each other along the lines. On trapezoidal slopes, triangular are installed and connected to a rebate. Bending should be done with maximum effort so that the elements do not move after installation. Next, you need to make and attach the legs. They can be made from leftover copper sheets.
The width of the legs should be approximately 110-150 mm, 25 mm are left for looping. Dimensions may vary depending on the parameters of the lines. The marked parts are cut and folded. Holes need to be drilled for rivets to be made through two layers of copper.
The roof, base and legs are brought together. If protection from birds is provided, a copper net should be installed. It is fixed on special corners. The roof is riveted.
