How to carry out the entire complex of roofing work around a chimney correctly

Maintaining the integrity of your roof and avoiding leaks during roofing work requires careful attention to detail in the area surrounding your chimney. There are a few crucial steps in this task that must be carefully completed in order to guarantee that everything is sealed correctly and operates as it should.

First and foremost, it’s critical to look for any indications of wear or damage to the chimney and the surrounding roof area. By taking care of these problems early on, you can avoid later, more expensive repairs. Water seeping into your home can be avoided with proper flashing installation around the chimney.

Next, you’ll have to be very mindful of the supplies you utilize. High-grade, weather-resistant materials should be used to create the flashing. For a barrier to be seamless and functional, it’s also critical to ensure that the shingles or other roofing materials are installed correctly.

Finally, to guarantee that the area surrounding your chimney stays in good condition, routine maintenance and inspection are essential. You can identify possible issues with this section of your roof before they become serious ones by keeping an eye on it.

Step	Description
1. Inspect the Chimney	Check for any damage or wear around the chimney. Ensure the area is clean and free of debris.
2. Remove Old Flashing	Carefully take out any old flashing and roofing materials around the chimney.
3. Install New Flashing	Place new flashing around the chimney, making sure it fits snugly and seals well.
4. Apply Roofing Material	Apply roofing material (shingles, tiles, etc.) around the chimney, ensuring proper overlap and alignment with the flashing.
5. Seal Joints	Use a high-quality sealant to seal all joints between the flashing and roofing material to prevent leaks.
6. Inspect the Work	Check the completed work for any gaps or issues, and make any necessary adjustments.

Sealing a pipe on the roof

When sealing a roof-mounted chimney, consideration is given to the pipe’s shape and the roofing’s relief:

-A metal apron works well for designs that are square and rectangular;

-Elastic rubber or polymer penetrations are frequently utilized for round outlets;

-Sandwich-style pipes have a steel apron with a metal cone attached at an angle;

-The Master Flash system or lead abutment strips are installed on slate or metal tiles.

Places where pipes pass through the roof

There is a pattern: it will take more work to waterproof the joint between the chimney and the roof the lower the pipe is positioned along the roof slope.

Corrugated sheet roofs have pipes installed in the following locations:

– Close to the ridge. Placing the device close to the ridge will lessen the chance of snow pockets and condensation forming, per SNiP 41-01-2003.

-Adding insulation to the slope-facing chimney. Maintaining the integrity of the rafter structure and lowering the chance of leaks are achieved by placing the chimney passage 500–700 mm from the roof ridge. Additional apron components or elastic penetrations will aid in joint protection.

STRUCTURAL ELEMENTS OF THE ROOF CONNECTION TO THE CHIMNEY

Start with a wooden box if you intend to create a chimney passageway through the roof using your hands.

1. Measure the length of the bars, increasing the pipe’s size by 15–25 cm, and choose bars that match the floor beams’ minimum thickness of 5–10 cm.

2. Join the boards to create a structure that is square or rectangular and attaches to both the vertical and horizontal floor beams, matching the shape of the chimney.

3. Prepare the following extra materials: sealant, tie (a long, smooth sheet with a flange to drain rainwater), and top and bottom aprons.

4. The top, bottom, and sides of the abutment strips that make up the apron are put in place. To drain water, an internal apron is positioned beneath the roofing material. Underneath it is a tie tied the same length as the lower apron from the cornice. In addition to serving as ornamental elements, external junction strips keep moisture out of the space where the chimney enters the roof.

5. The hole around the pipe and floor beams will be sealed with the aid of basalt wool. The space between the brick and concrete chimney and the rafter system’s components is 13 cm. A 13 cm heat-insulating layer sits between them, and there is a 25 cm gap from the ceramic, non-insulated pipe.

6. Sheet metal is used to cover the space between the pipe and the combustible material. A unique film, the edges of which are fastened to the outside of the pipe or wooden box and cut through with an envelope, ensures the roof’s tightness.

It is sufficient to choose an elastic seal when organizing a round pipe’s output; extra waterproofing protection around the penetration is not necessary.

SKATE CUTTING

Water can be drained away from the smoke system passing through the ridge with the help of a decorative seal made of slate or corrugated board and a smooth metal apron.

1. Place a tin sheet (tie) beneath the roofing close to the pipe.

2.Abutment strips on the bottom, side, and top should be fixed first.

3. Use silicone-based sealant to fill the joints next to the pipe.

4. Apply pressure using the apron’s upper strips.

ROAD WALKING

Make sure the drainage gutter is fixed on the roof slope when building a small penetration.

It will be necessary to create a slope on the roof in order to cut pipes wider than 80 centimeters so that water from above can drain into the chimney’s center.

On top, two small valleys, or grooves, form. In order to prevent water from entering the under-roof space, the lower valley strip is installed at the joints of negative angles. It is positioned prior to the corrugated sheeting being laid. The upper bar serves only aesthetic purposes.

BYPASSING THE RAFTER SYSTEM

If the sheathing is rigid enough to distribute the load evenly, a high-quality abutment of the roof to the chimney pipe can be achieved. Installing the chimney comes before fortifying the rafter system most of the time.

If the output is completed later, it is crucial to leave more than 20 cm between the rafters; if not, the sheathing will need to be taken apart, which will weaken the system as a whole.

1. Install support posts beneath the rafter frame components, remove the floors, and use horizontal crossbars to join them to the entire rafter.

2. Place a sturdy frame that is securely fastened to the roofing sheathing and rafter system around the smoke outlet.

Chimney passage through a roof made of metal tiles

The following supplies and tools must be ready in order to waterproof a chimney on a metal tile roof:

-a marker or construction pencil;

-a drill and a drill set;

-grinder featuring a 2 mm disc;

-aluminum clamps and cassettes;

-a lengthy tape measure or ruler;

-hammer and pliers.

When a metal tile roof is bypassed, two protective layers must be created. They are constructed as follows:

1. Installed on the sheathing is an interior apron that covers the chimney and roof.

2. Prepare the lower apron and the external decorative strips that cover the roofing material.

The edge of the upper strip is inserted beneath the ridge element if the smoke system is situated close to the ridge.

The riser’s lower wall is where the internal apron is arranged first.

1. Each element rises vertically along the ventilation structure to a height of 150 mm, covering the slope by 200 mm.

2. The side strips extend 20 centimeters past the pipe and pass beneath the metal tile’s ridge to completely cover the apron’s lower element.

3. Self-tapping screws are used to securely fasten all components.

4. Measure 15 cm on the pipe and carve a 15 mm deep groove with a grinder.

5. The lower junction bar is then fixed after silicone sealant has been poured into the ditch.

Crucial! The apron’s upper portion should slide snugly into the sealant-filled groove.

All that’s left to do is install the roofing material, use self-tapping screws to secure the top strips to the chimney, and apply waterproofing mastic to the sealing line.

Cutting for round pipes: metal penetration

An inclined truncated cone covered by a prefabricated apron-cap, which is symbolized by a metal sheet with a hole, will aid in sealing a circular chimney.

1. After the pipe is threaded through a cap and the upper portion of the cap is pressed against the chimney using a steel clamp and a heat-resistant gasket, the sheet is fastened to the sheathing.

2. Using pliers and a hammer, a bead is made along the sheet’s edge in an attempt to direct the water’s flow downward.

That’s interesting to know! A round chimney apron is constructed from black steel that has a thickness of 1-3 mm. Heat-resistant enamel, capable of withstanding temperatures as high as 600 degrees, is applied to the metal. Stainless steel components with a maximum thickness of 2 mm can also be produced.

Master Flashes are elastomeric penetrations with a soft lead or aluminum base that resemble a stepped pyramid. The design is easily adjustable to the steepness of the roof and can withstand an operating temperature range of 50°C (+ 130°C).

The following procedure is followed when installing the elastic assembly of the roof-through passage:

1. Pick a seal ring whose gap is 20% smaller than the ventilation system’s diameter.

2. The seal is pulled over the pipe after it has been wet with a soap solution beforehand.

3. Sealant and screws fitted with rubber or neoprene gaskets hold the cap in place. 35 mm is the pitch.

Crucial point Flexible lead or aluminum rings used in elastic penetrations have an adhesive layer hidden beneath a protective film. Add more adhesive to improve the fixation process.

ALUMINUM AND LEAD TAPES

Waterproofing the chimney with self-adhesive aluminum/lead tape made of modified polymers or bitumen is an alternative to pre-made penetrations. It makes it possible to seal the joints where the pipe and roof meet.

Self-adhesive tape can be used to waterproof a pipe in multiple steps:

1. After cleaning the area to be taped, firmly press the film.

2. Use sections to cover the chimney’s vertical portion while also covering the roof’s horizontal portion.

3. Use a metal strip to clamp the tape, and then use heat-resistant dowels to secure it.

Sealing rectangular and square pipes

When it comes to valleys and junctions, a metal tie (junction strips) placed 150–200 mm below the covering will help guarantee the stability of the roof.

Roofing sealant is used to seal the intersection of the apron and the corrugated sheet surrounding the chimney. To direct the flow of precipitation onto the roof slope, eaves outlets are placed at the bottom and sides of the structure.

It is essential to use a membrane to seal the riser passage before covering it with corrugated sheet.

1. Cut the material into a cross shape and adhere it to the chimney walls at a height greater than 5 cm with glue.

2. Under the upper abutment bar, a self-adhesive tape known as "Vakaflex" is affixed from below, the side, and above.

At times, the chimney is installed in a completed roof, leaving a 1.5–2 cm gap in the corrugated sheet. This is accomplished by bending the metal sheet at the intersection of the rectangular pipe, adhering a waterproofing membrane, and installing the lower sheathing first, followed by the upper sheathing, pressing firmly against the chimney and roofing cake.

Plastering the pipe

You should be aware of the correct methods for properly insulating the pipes to prevent the buildup of a thick layer of plaster:

1. First, use cement mortar to seal all of the pipe’s current imperfections;

2. Next, install reinforcing mesh on the walls;

3. Plastering is the last step.

Crucial! Bring the mixture of lime, cement, and slag chips (or sand) to the consistency of sour cream before adding the first layer, and then sprinkle without leveling. Denser in nature, the second coating is applied with a trowel and rubbed until a smooth surface is achieved.

Strengthening the pipe with asbestos cement

It is necessary to apply a cement-lime mixture to the slabs’ surfaces in order to line a chimney with asbestos cement.

1. The first layer of solution is sprayed on after the chimney is strengthened with mesh.

2. The insulating sections receive a fresh layer of mixture that is applied and adhered to the chimney’s surface.

Experts advise against using asbestos in residential areas because it contains dangerous carcinogens.

Sheet iron cladding

You should keep flammable materials 60 centimeters away from the chimney when insulating a metal pipe.

1. A 5 cm thick layer of mineral wool is wrapped around the structure, overlapped, and clamped with steel wire. Cover the top with a sheet of metal.

2. The pre-made holes are filled with rivets, and a special tool is used to close the clamps’ heads.

QUESTION: WHAT IS THE GOAL?

The precise location of the pipe coming from the furnace must be included when creating drawings.

-The chimney’s outer wall’s maximum heating temperature shouldn’t go above 50 degrees.

You can adhere to regulations by waterproofing a brick chimney on the roof. Metal components will need more insulation to keep condensation from forming.

It is sufficient to install millite silica, thermal insulation wool MKRR-130, or rolled felt MKRF-100 after installing the pipe.

Although doing roofing work near a chimney may seem difficult, it can be simple if you take the proper approach. You can stop leaks and prolong the life of your roof by paying attention to appropriate sealing and making sure the right materials are used. To keep water out, make sure that all joints and gaps surrounding the chimney are properly sealed.

The secret to preventing possible problems is routine maintenance and inspection. Periodically inspect the flashing and other roofing elements surrounding the chimney to look for early signs of wear. Maintaining these areas properly will help you steer clear of future, more expensive repairs.

In conclusion, a well-done roofing job surrounding your chimney adds to the overall durability of your house in addition to improving safety. You can make sure your roof stays in great shape for many years to come by being meticulous and doing regular inspections.

To avoid leaks and damage, it’s imperative to take a precise and cautious approach when doing roofing work near a chimney. To properly secure the area around the chimney, this process entails installing flashing correctly, using the right sealing methods, and aligning the flashing precisely. By taking these precautions, you can protect your home from potential water damage and structural problems while also extending the lifespan of your roof.

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