Almost all residential buildings are equipped with one or another air purification system during construction or reconstruction. And whatever type of ventilation, passage through the roof is an important stage in its construction. For each type of roofing material, the device of the passage nodes should be carried out according to its own scheme. In order for the system to serve without fail for more than one year, all installation activities should be carried out competently. Familiarize yourself with the methods of installing the ventilation pipe on the roof, and this information will help you in your work.
Discharge of exhaust air from the house
If you are starting the construction of the cottage from scratch, then be sure to provide for the construction of ventilation ducts in the brick walls of the interior. Natural ventilation will not require expensive equipment and will constantly provide premises in your home with fresh air.
If necessary, you can supplement the system with a fan for forced extraction. But the extra costs will not be needed if you wisely conclude that the ventilation on the roof.
The higher the ventilation pipe on the roof of the apartment building, the stronger the draft will be in it.
Often, designers pay insufficient attention to the construction of risers and the height of the ventilation shafts above the roof of the building. Due to their shortcomings, a number of unpleasant phenomena can occur:
- smells penetrate from the bathroom and from the kitchen into the living rooms due to the unlawful combination of ventilation ducts into one common duct for ventilation on the roof;
- the effect of the hood is negligible due to insufficient pipe length;
- the hood operates in the reverse mode due to an incorrect choice of location for installing the ventilation pipe on the roof slope;
- ducts and ventilation pipes on a cold roof freeze without thorough insulation.
The cause of problems when installing ventilation pipes on the roof is often the complex structure of a modern roof, which is called a “roofing cake” for its multi-layer structure.
In case of improper installation of the ventilation pipe on such a roof, the rafters and the crate can be damaged. There may also be gaps in those places where the vent cover is installed, and rainwater will leak through them. Therefore, in order to maintain the tightness of the roof, it is recommended to use passage elements specially designed for this.
Ventilation passage planning
To begin to equip the ventilation system properly, you should think through and draw up a ventilation concept for your entire home.
Let's take an example of this situation: according to the plan for the reconstruction of a residential building, the roof will have to be replaced. Through the new roof you need to remove the hoods from the rooms, from the bathroom, the ventilation duct from the basement and the kitchen hood. The question arises, what will happen if you do not four passes, but bring all the channels together and put only one ventilation pipe on the roof?
Knowledgeable people argue that nothing good will come of such savings. Nevertheless, it is desirable that there is a separate ventilation passage through the roof for each of the ducts.Otherwise, if all of them are combined, an unpleasant odor can spread throughout the house when weather conditions will provoke the occurrence of backdraft.
When installing a new roof, you can plan the location of the ventilation pipes on the roof in advance and make passages for them, if the location is known exactly.
Purpose and types of roofing penetrations
Passages through the roof are arranged to output various types of ventilation:
- internal premises of the building;
- sewer riser pipe;
- attic roof space.
In addition, it may be necessary to equip the exits of chimneys and television antennas.
The final upper element of the duct system is a specially made pipe section called the ventilation outlet. Mounted in accordance with all the rules, the ventilation pipe on the roof provides air exhaust from the premises and prevents water leakage under the roof. In those places where you need to arrange the passage of ventilation through the roof, install passage elements corresponding to a certain type of roofing materials.
Homeowners have the opportunity to purchase ready-made sets of various ventilation outlets for installation on roofs made of hard and soft materials. With their help, it is easy to carry out the output of the ventilation strut on the roof so that the roof does not leak and does not lose its aesthetic appearance. Such devices also protect the ventilation ducts from ingress of dirt and precipitation.
Depending on the design of the roof of your house and the type of venting, the passage through the roof may be of different heights and shapes. In addition to exhaust pipes of circular cross section, rectangular ducts for ventilation to the roof are also used.
In order for the ventilation pipes on the roof not to cause a violation of the tightness of the roof, the places of their passage should be equipped with special care.
Venting unit assembly
The design of the simplest nodes of the passage of the ventilation pipe through the roof is a metal pipe, which is inserted into the hole and fixed on a reinforced concrete or steel cup. The roofing aisle can be equipped with a closing valve and a ring for collecting condensate. From below, a discharge duct is connected to the pipe through a flange. From above, this unit can be equipped with a deflector or a simple protective umbrella. There is an option with insulation, which is used as mineral wool.
Products for roof ventilation of a new level of quality are considered more relevant to the technical and aesthetic requirements of the modern era. The principles of the arrangement of such ventilation outputs are almost the same regardless of the manufacturer, they are distinguished only by small differences. Of a number of similar products, the most popular are ventilation exits to the roof, ventilation covers and ventilation fungi to the roof of the Vilpe Vent brand.
Their advantages:
- the inner pipe is made of galvanized steel, and the outer one is made of durable and lightweight polypropylene;
- the outputs are fastened to a reliable passage element of the corresponding form;
- pipe height varies in different versions from 400 to 700 mm;
- the lower part of the pipe is equipped with a sealant and can be inserted into the duct to a depth of 300 mm;
- the inner diameter of the pipe ventilation outlets is from 110 to 250 mm;
- the vent outlet pipe is thermally insulated to prevent condensation and ice plugs;
- it is possible to put an electric fan on the ventilation output;
- a hood with a deflector protects the pipe from precipitation and enhances traction.
In some cases, the feed-through element is not included in the package and must be purchased separately.Choose it taking into account that the form of the lining of the passage element matches the type and profile of the roofing.
Feed-through elements provide the versatility of installing a ventilation pipe on any roof. Their installation can be carried out both simultaneously with the construction of the roofing, and on the finished roof. With these products you can have no doubt in the stability and tightness of the ventilation outlets.
The importance of roofing aerators
In winter, condensation forms inside the roof structures and in attics. In order to protect the roof from dampness, the formation of fungus and mold, you will need to provide ventilation of the space under the roof.
The roof ventilation unit is extremely simple in design. The air should naturally move from bottom to top under the roof. Holes in the ledge will serve for its entry, and it will exit through aerators with a vent cover, arranged in the roof closer to the ridge.
To cover the hole from precipitation, use a cover for ventilation of various configurations, including a ventilation fungus on the roof, which is actually a decorative cap.
Roof ventilation outlets
Experts advise making the location of the ventilation pipes on the roof exactly above the corresponding riser. In this case, without bending the channel, the efficiency of the air flow will be maximum. If this is not possible, then you will have to use corrugated adapters to connect. On pitched roofs, it is rational to arrange a roofing closer to the ridge. The advantages of this option are that the long inner part of the pipe will remain warm under the roof, and the shorter upper element will be much more stable under the blows of the wind.
The height of the ventilation shafts above the roof of the building also matters. With a low location, the draft will be weak, and a pipe that is too long will have to be fixed with braces. Guided by building codes, you should mount the ventilation pipe on a sloping roof to a height of 50 cm above the roof. If the roof is flat, the height of the chimney can reach 30 cm. In the case where recreational areas are located on the flat roof or it is operated in another way, then the height of the ventilation outlet must be at least 2 meters.
Whichever option you choose for the location of the ventilation pipes on the roof, the main thing is that their ends are above the so-called wind backwater zone. Otherwise, a strong wind can block the air flow and even direct it back.
Correct installation of air duct penetrations
Consider an example of how to install a ventilation pipe on a roof made of metal. The device of a roof ventilation installation will be similar for other types of roofs, with only some differences.
The sequence of steps for installing a ventilation outlet on the roof:
- Determine the installation location on the roof of the bushing.
- Outside, on the top wave of the metal tile, draw the contours of the hole according to the template supplied with the product.
- Cut a hole in the tile with a chisel and scissors for metal to exit the ventilation pipe to the roof.
- Cut the corresponding holes in the lower waterproofing layers of the roof.
- Mark according to the template and drill a series of holes for self-tapping screws.
- To clear a surface of a metal tile around an opening of moisture and dust.
- Apply a layer of sealant to the bottom surface of the gasket.
- Lay the gasket in the intended place.
- Install the feed-through element on the gasket and secure it with self-tapping screws.
- Insert the exhaust outlet pipe into the bushing and check for verticality.
- Secure the pipe with screws in the correct position.
- Ensure that the ventilation outlet for the metal tile to the roof from the attic side is tight.
At the end of the installation of ventilation on the roof, the base of the passage element should be so tightly pressed to the roof that excess sealant extrudes from under the gasket.
In the video below, you can familiarize yourself with the process of installing the ventilation pipe on the roof from corrugated board. In the same uncomplicated way, you can install a ventilation outlet on the metal roof of your house.
Time to take stock
You could make sure that there are no special difficulties in the process of installing ventilation on the roof and installing the pipe, which we examined. Your ventilation system will certainly be effective if you calculate in advance the height of the ventilation shafts that rise above the roof of the building. And the service life of the roof, disturbed by the passage of the ventilation outlet through it, will not be reduced at all if you responsibly regard the quality of installation work.
