No matter how hard roofers try to lay the roofing material as tightly as possible to the pipe, leaks still form in these places. If you leave them unsealed, then water will leak through them into the under-roof space. Therefore, all cracks in the places where the roof adjoins the pipes and various protrusions must be closed.
There are several ways to seal cracks depending on the type roofing material and the size of the gap.
1. Small gaps can be closed with silicone sealant. You just need to choose a brand that can be used at high temperatures. This is especially important when sealing the gap around chimney.
2. On tiled roof an “otter” made of cement-sand mortar is installed around the pipe:
This work must be done with great care, otherwise the structure will crack and leak over time.
If the pipe runs next to the ridge, then the gap is sealed quite simply:
This method perfectly protects the roof from rain, but snow gets into the gap between the slate and the pipe.
To make the joint between the pipe and the slate airtight, you need to do the following:
When installing a soft roof, cutting is carried out around the pipes (apron, framing using Wakaflex, etc.). The cuttings are pressed with a case made of a pipe whose diameter exceeds the diameter of the ventilation pipe. The gap between the pipe and the casing is filled with bitumen mastic.
Note: “Vakaflex” is a roofing tape, the purpose of which is to seal cracks where the roof meets pipes and walls. It is a self-adhesive rubber-based tape. The tape is reinforced with aluminum mesh. Elastic, easily takes any shape.
Before pouring, wide cracks are caulked with rope or flaxseed, impregnated with oil paint. After this, the gap is filled with mastic and coated with a cement-sand (greasy) solution on top.
As you can see. There are many ways to seal the gap between the pipe and the roof. They have one thing in common: all work must be done efficiently. This is the only way you will achieve reliable protection of the roof from moisture.
The service life of a fireplace or stove largely depends on how and with what exactly the chimney is sealed using stainless steel or other materials.
Correct installation does not guarantee the absence of problems with combustion products entering the room. Over time, pipe materials are subject to thermal deformation, which leads to ruptures and cracks in the structure.
This leads to a decrease in draft, as a result of which a large volume of combustible material is required to heat the house, and because of this, soot intensively settles on the inner surface of the pipe. The latter is especially dangerous, as it not only leads to the formation of condensation, but can also cause a pipe fire.
For this reason, for the stable functioning of a chimney made of stainless steel or any other materials, it must be regularly inspected and any deficiencies that may arise must be promptly corrected. To avoid problems in the future, it is better to seal all cracks and joints to avoid defects.
On construction market a wide range is presented. The entire wealth of choice is conventionally divided into heat-resistant and heat-resistant sealing agents, although, of course, there are many more varieties.
By sealing the cracks of stove or fireplace pipes, combustion products will not enter the room through them. Reliable insulation makes using a stove, fireplace or boiler as safe as possible.
Watch video - high-temperature products for stainless steel and other materials
As the name suggests, one-component sealants consist of one component and do not require mixing of ingredients before the sealing procedure. This makes them easy to use and popular with home owners who appreciate the ease of use of the insulation product.
Two-component However, before starting work you need to mix it, strictly observing the proportions specified in the instructions. In this case, the finished product should be used within several hours after mixing. This option is not suitable for sealing joints with your own hands; professional builders usually use two-component insulation.
In addition to chimney insulation, sealing compounds are also used to insulate structural seams heating system based on an electric boiler when eliminating pipe leaks.
Wondering how to seal a chimney from of stainless steel, glass, plastic or ceramics, you should pay attention to fireproof silicone. This material promotes close contact of structural parts with each other and reliable insulation. The main advantages of silicone composition:
Silicone sealants come in two types:
An additional advantage of silicone-based products is that as a result of heating, the iron oxide contained in it turns brown, which makes the insulation more invisible against the background of a roof or brickwork.
According to their temperature characteristics, insulation products are divided into heat-resistant and heat-resistant. They are used to seal joints between different sections of a structure, as they can withstand different temperatures. If heat resistant are only suitable for external surfaces, then heat-resistant ones can seal the cracks of a high-temperature chimney, where especially high temperatures.
This type of insulation is suitable for working with external walls fireplace, stove, and joint processing brickwork and roofs.
It should not be used for stainless steel pipes, as it has a rather low heating temperature - only 350°C.
Heat-resistant sealant is made from silicone. The temperature range at which a product can be used is affected by the additional components present in the product and their percentages. The most common additional component is iron oxide, which gives insulation brown tint.
The main characteristics of this type are as follows:
Silicone has few disadvantages, but they still exist:
Curing speed of heat resistant insulating material depends on the temperature at which the work takes place. At low temperatures and high humidity, the composition will take longer than indicated on the package. In dry air and high temperature it will harden faster. The insulation also adheres better to a dry surface.
Heat resistant insulation agent – the best option How to seal the joints of a metal and stainless steel chimney. This is explained by the fact that silicate, which is the main component in the refractory composition, perfectly withstands high temperatures up to 1200-1300°C, and under short-term load – up to 1600°C.
Watch the video – stainless steel versus galvanization
The silicate composition is suitable for sealing cracks in fireplaces and stoves where there is direct contact with fire. Typically, high temperature insulation material is gray or black.
The main advantages of fire-resistant silicate:
Although all silicate heat sealants can withstand high temperatures, in order to seal areas that will come into contact with flames, it is better to use only non-flammable sealants labeled “fire-resistant”.
You should not apply silicate sealant in several layers to increase its wear resistance: this way it will not be able to dry out and will become covered with cracks. The required width and depth of application are indicated in the instructions. The silicate product adheres better to a damp surface, so before starting work it is better to slightly moisten the area where you plan to apply it.
Another way to seal joints and cracks is with heat-resistant adhesive and sealant. Adhesive composition for insulation it can be made on the basis of materials such as acrylic, silicone or polyurethane. The composition allows not only to seal seams, but also to reliably glue the surfaces of materials together. The adhesive has excellent waterproofing properties and has good adhesion to natural materials and concrete.
Most often, difficulties are caused by the heat and waterproofing of the fireplace, or more precisely, by leading the stainless steel pipe through the roof and sealing the joints between them. This is important not only for high-quality pipe insulation, but also to ensure that the roof does not leak.
The place where the pipe connects to the roof is called the chimney outlet. This is a key part of the entire structure that must be carefully sealed. The durability of the roof and the quality of the heating system depend on its reliability.
Most modern roofing materials, in addition to the main elements, have special parts made of non-flammable compounds, with which you can surround the chimney as tightly as possible with a coating and prevent heating of the roof from a hot chimney and possible fire. Thus, insulation also performs fire protection functions.
Even if the house does not have a fireplace or stove, and it is heated using a boiler, there is still a need to purchase a sealant for the boiler to ensure good draft and stable operation of the heating device.
Most sealing compounds are packaged in cartridges or tubes with a sharp tip, which must be cut at an angle of 45° before starting work. It is important to make a hole of the same diameter as the future seam.
Squeeze out the sealant using a standard construction gun, applying it evenly to required areas chimney. If a collapsible stainless steel chimney pipe is being treated, then the composition is applied only to the joints, so that in the future it can be easily cleaned and the elements can be disassembled for cleaning.
There are several simple rules for working with sealants:
The sealing compound should be used as follows:
Next, the cracks, crevices and joints are sealed: the work must be done strictly with gloves, observing the thickness and width of the seam specified in the instructions. It is important to ensure air access to the place where the composition is applied: this is necessary for its proper hardening.
If for modern finishing materials There are sealants made of silicone and silicate, so to seal a slate roof, a method known to our grandfathers is suitable - a mixture based on asbestos and cement.
The chimney is sealed with cement as follows:
When choosing suitable remedy for hydro- and thermal insulation, they are guided by the conditions under which the stove, fireplace or heating boiler will be used. It is also important to consider where exactly the product will be applied: inside the pipe, outside or at the junction of the chimney and roof. The choice of sealant is also influenced by the heating temperature of the surface that is planned to be treated.
Watch the video - a stainless steel pipe after 2 years of operation (external galvanized and internal stainless steel)
You shouldn’t skimp on chimney sealant, because forced regular cleanings, as well as the need to re-disassemble the structure, will bring much more costs, and you won’t be able to save money. In addition, poor-quality sealant can lead to soot getting into living spaces, the formation of plaque on the walls, poisoning of residents, or even a fire.
Bringing a pipe or ventilation shaft through the roof involves making a hole in it. When a pipe passes through, there always remains a gap, which, even at its lowest value, will allow moisture to pass through. Today we’ll look at how to achieve perfect tightness at the junction of the pipe and the roof and how to seal the resulting gap between the pipe and the roof.
In this article
When venting a chimney, a hole is always made in the roof with a slightly larger diameter than the chimney itself. This is due to the need for convenient and trouble-free pipe installation and safety rules. If the pipe gets very hot and the roofing pie is formed from flammable materials, then the gap between the pipe and the roof reaches 15 cm.
Poorly sealed joints are fraught with a number of unpleasant consequences:
Competent and thorough sealing of the gap is a guarantee of long and reliable service for the roof and the entire house. Let's take a closer look at how to seal the gap between the pipe and the roof on various types roofs.
Closing the cracks is carried out using a number of available materials, which can be schematically divided into two categories:
For different types roofing ratio and the choice of these materials will be different. Let's consider this issue in more detail.
On tiled roofs It is more convenient to use a solution of cement and sand. For this type of roof this is the best and convenient solution sealing gaps.
Let's imagine step by step how to seal a pipe on a tile roof:
How to seal a pipe on a slate roof? The answer is simple: asbestos-cement mixture. 
The work order will be as follows:
On the roofs of flexible tiles cutting is done. The gap must be closed with a special apron element. It is framed with flexible adhesive tape such as “Vakaflex” based on rubber.
The tape is placed on the chimney and base and carefully glued using its own adhesive layer. Next, the groove is pressed against the pipe casing and all gaps are filled with bitumen mastic. If the gaps between the chimney and bitumen shingles
If they are large enough in size, they are initially filled with tow or rope, which are impregnated with bitumen or oil paint.
Roof made of corrugated sheets The question of how to seal a gap between a pipe and a roof made of corrugated sheets is easily solved with the help of ready-made pipe cuttings, which allow you to quickly and efficiently seal all the gaps. Finished pipe cuts represent the connection of the apron and cap in a single piece. They are made from various materials and are designed for wide range
temperature fluctuations.
Repair of leaking pipework
Sealing the gaps between the pipe and the roof is a simple but responsible task. Even a novice builder can handle it. To carry out this work correctly it is necessary to take into account:
The modern market offers a wide selection of not only various sealants, but also ready-made cuttings for organizing a high-quality connection between the pipe and the roof. We advise you to pay attention to them when arranging a chimney with your own hands.
Installing a chimney is usually not a difficult process, however, in some places, such as floor crossings, some difficulties may arise. An important point is to ensure proper waterproofing. We will talk about this and other nuances related to how to seal a chimney pipe in this article.
Even if the pipe is placed as tightly as possible on the roof, minor gaps will still remain. When it rains through them in attic space moisture will constantly enter, which will lead to deterioration over time roofing structures. This is why roof pipe sealing is so important.
The easiest way to solve the problem of how to seal the gap between the pipe and the roof is to install an apron on top. You can do it yourself, in which case you will need to provide strips for connection to the pipe in advance. There is an easier way - to buy a ready-made stainless steel roof passage. Often, passages are made for the chimney round shape, and they are made of stainless steel; a galvanized chimney pipe is also used, most often. The passage is placed on the pipe, and the joint is fixed with a steel clamp.
If you need to cover up minor gaps formed between the pipe and the roof, then for these purposes you can use silicone sealant(read: " "). You can find a huge variety of them on sale, but we need a heat-resistant type.
The process of how to seal the roof around round pipe, will be slightly different depending on the type roofing, that is, in addition to the basic recommendations, there are also algorithms that will differ somewhat.
Sometimes the question arises of how to seal the gap between the pipe and the slate.
The technology provides the following sequence:
On a tile roof, it is best to seal the cracks with a solution of sand and cement, which will best protect the inside of the building from moisture and precipitation.
To achieve the best moisture insulation, you will need:
Among the options for covering a pipe on the roof if it rises above a bitumen roof, the most optimal is to use self-adhesive tape Wakaflex.
You can perform isolation in this way:
In essence, Master Flash is an apron cap made of silicone or rubber, placed on an aluminum base.
As for operating temperatures, silicone version products it is significantly wider - in the range from -50 to 130 ℃.
The process of sealing cracks on a profile roof includes the following manipulations:
Often the described manipulations do not provide sufficient tightness on the profile roof, so that during rainfall water leaks into the cracks. In such cases the best option is the use of self-adhesive tape, aluminum reinforced. It is very convenient to use such material, since it does not require pre-heating before use.
Thus, the fact how well a corrugated roof will be sealed at the exit point of the chimney depends largely on the choice of material and the quality of the work performed. However, we are confident that by following our instructions exactly and working responsibly, you will be able to protect your home from any surprises associated with roof leaks.
Despite all the efforts of roofers to lay the roofing material closer to the pipe, it still adjoins it loosely, with gaps. If they are not sealed, water will seep under the roof through such joints. Therefore, all gaps between the roof and the perimeter of the chimney must be sealed.
How to seal the roof around a pipe on a roof made of metal tiles, seam roofing or corrugated sheeting?
Let's consider a sealing method for a rectangular brick pipe.
Externally, Master Flash looks like a stepped pyramid. The materials for its production are silicone or rubber, the base is made of aluminum. It should be remembered that the operating temperature range of the rubber Master Flash is – 50°С–(+ 130°С). He will tell you more about the chimney.
The silicone model operates in the temperature range – 70°С–(+ 250°С) and can be used on any roof and in any climate.
The described material is easy to install and has a long service life.
On such a roof, a so-called roof is installed around the pipe. “otter” from cement-sand mortar in the following sequence:
This work must be carried out with all possible care to prevent cracking.
When the pipe is located close to the ridge, it is sealed in the following sequence:
To ensure that the pipe and slate are joined hermetically, do the following:
Around brick pipes on soft roof cutting is carried out in the form of an apron from ready-made joints made of soft roofing material (for example, ondulin). The junctions are attached to the sheathing with nails, and to the pipe walls with Wakaflex or Onduflesh-super roofing tape. The joints of the junctions with the sheathing are also glued with the same tape.
Round pipes on a soft crawl are sealed using ready-made aprons-caps. The joints of the base sheets of the aprons with the roof are also taped with roofing tapes.
As you can see, there are quite a few ways to seal a roof pipe. They have one thing in common: all this work must be done efficiently. Only in this way will you receive reliable protection roofs from leaking.
