Vaillant EPP pitched roof flashing, black, 25°-50° - recoVAIR /4

Product detailed description

Vaillant EPP transition piece for pitched roofs 25°-50°, black - for the recoVAIR /4 system

The pitched roof transition piece is an original roof component from the Vaillant recoVAIR /4 product range, which solves the passage of the main EPP (expanded polypropylene) ventilation ducting through the pitched roof of a family house to the outside, or conversely brings fresh air from the exterior to the central heat recovery unit. It is a universal black collar (sleeve) supplied in a single version covering the common roof pitch range from 25° to 50°, so that the designer or installer does not need to source a separate part for each specific roof pitch - it is enough to choose this universal transition piece and trim/adjust it on site according to the actual pitch of the roof covering.

The part connects to round EPP ducting with an outer diameter of 210 mm and an inner diameter of 180 mm (commonly denoted as Ø210/180 mm), which forms the main route of supply or exhaust air between the central unit recoVAIR VAR 150/4, VAR 260/4 or VAR 360/4 and the exterior, or the roof outlet. Due to the EPP material, the transition piece is lightweight, rigid, and also has its own thermal insulation capability, which at the point of roof passage (typically a cold, uninsulated part of the structure) significantly reduces the risk of condensation on the surface of the ducting.

Technical characteristics

• Purpose: roof passage for EPP ducting for pitched roofs with a pitch of 25° to 50°
• Colour: black (resistant to UV radiation and weather effects)
• Material: expanded polypropylene (EPP), closed-cell structure
• Connecting duct diameter: Ø210/180 mm (outer/inner diameter)
• Joint type: overlapping slip joint, compatible with other EPP parts of the recoVAIR /4 system
• Own thermal insulation thanks to the EPP structure - reduction of thermal bridges at the point of roof passage
• Resistance to moisture and weather conditions for outdoor installation
• Compatibility with units: recoVAIR VAR 150/4 L, VAR 150/4 R, VAR 260/4, VAR 260/4 E, VAR 360/4, VAR 360/4 E
• Country of origin: Germany (Vaillant Group manufacturing plant)
• Warranty: 2 years from sale to the end customer (extension possible upon system registration according to current manufacturer conditions)

When you need this transition piece

You will use the pitched roof transition piece whenever the central heat recovery unit draws in fresh air or exhausts waste air through the roof structure, and the roof pitch of the house is in the range of 25° - 50° (i.e. the vast majority of common gable, hip or half-hip roofs on family houses). Typically you will encounter it in two scenarios:

• Exhaust of stale air from the unit through the roof to the outside (exhaust port of the unit - EPP ducting Ø210/180 mm - this transition piece - roof covering - chimney cap/exhaust head).
• Intake of fresh outside air through the roof (opposite flow direction, same physical part, since it is a passive passage without a fan).

An alternative to this transition piece is the part for a flat roof (a separate product in our offer) or a side outlet through the facade, which is however solved with completely different components. So if the project is designed with a vertical roof passage and the roof is pitched, this is the correct and only necessary choice of transition piece.

Installation - procedure and recommendations

Installation of the transition piece should be carried out by a trained company experienced in roof passage installations (due to the connection to the waterproofing membrane and roof covering), in cooperation with the ventilation installation company. Basic procedure:

1. Before laying the roof covering or when it is dismantled, the exact location of the passage is determined according to the ventilation project (most often near the ridge or on a suitable area of the roof away from valleys and eaves).
2. An opening corresponding to the diameter of the transition piece is cut into the battens/sheathing, and the EPP part is slid onto the main duct Ø210/180 mm in the direction from the unit.
3. The lower (inner) collar of the transition piece is connected to the diffusion membrane or roof waterproofing membrane so that the airtightness and watertightness of this layer is maintained.
4. The universal collar is oriented and, if necessary, trimmed/adjusted exactly according to the actual pitch of the roof plane (25°- 50°) so that it seats on the covering without gaps.
5. The roof covering (tiles, sheet metal, shingles) is finished around the transition piece; a suitable UV-resistant sealing strip/collar is used at the passage point if the type of covering requires it.
6. The upper part of the transition piece (above the roof) is followed by a finishing piece, or directly a protective grille against insects and birds (depending on whether a separate above-roof component is used in the project).

It is important to maintain the minimum height of the passage above the roof covering according to applicable standards (protection against snow and rain being blown into the ducting) and to ensure that any condensate drains outward from the ducting, not into the unit.

Compatibility with the recoVAIR /4 system

This part is part of the closed accessory system for central units Vaillant recoVAIR /4 and is designed to directly connect to:

• straight sections of EPP ducting Ø210/180 mm (e.g. lengths of 500 mm and 1000 mm),
• fittings and bends of the same diameter,
• low-profile and classic air distributors installed in the ceiling,
• a finishing piece above the roof (a separate product, used for flat roofs or as an additional above-roof part).

Do not use this part in combination with ducting systems from other manufacturers with a different diameter or port profile - the joint might not be airtight, and you would lose the warranty claim for the functionality of the entire system.

Maintenance and care

As a passive structural part, the transition piece does not require any regular maintenance in terms of replacing components. It is recommended to:

• once a year (e.g. during a roof or chimney inspection) visually check the tightness of the connection to the covering and the condition of the sealing strip,
• during ventilation system inspection, check whether there is any leakage or ice formation at the passage point during winter,
• in case of mechanical damage (e.g. from falling branches or roof work), replace the transition piece immediately to avoid compromising the airtightness and watertightness of the roof structure.

Why choose an original Vaillant part

Even though it is "only" a roof transition piece, its dimensional and material compatibility with the entire recoVAIR /4 system is crucial for the correct function of ventilation with heat recovery. A non-original or dimensionally imprecise part can cause leaks, increased air flow noise, moisture condensation in the ducting, or reduced heat recovery efficiency of the entire unit. By ordering the original part directly from an authorized Vaillant partner, you have the guarantee of dimensional and material compatibility and the preservation of the warranty conditions for the entire ventilation ducting.

Why the roof passage is a critical point of the entire ventilation system

In controlled ventilation with heat recovery, it is precisely the roof passage that is one of the most stressed points of the entire ducting - it combines the thermal gradient between the heated interior and the exterior, mechanical stress from snow, wind and the thermal expansion of the covering, and at the same time it must remain perfectly airtight and watertight at the same time. A leaky or incorrectly sized passage manifests itself in practice as one of these problems:

• Increased pressure losses and noise - if the collar does not seat exactly on the ducting, turbulence and an audible whistle occur at the joint, especially at higher fan speeds of the unit.
• Condensation and leakage - warm humid air passing through the cold roof shell condenses on cold surfaces if sufficient thermal insulation of the ducting and tightness of the passage is not ensured.
• Water ingress into the roof structure - if the transition piece is incorrectly connected to the waterproofing membrane, rainwater can flow under the covering into the roof truss structure.
• Freezing of condensate in winter - during prolonged low temperatures, condensed moisture at a leaky point can freeze and gradually damage the material of the transition piece and the surrounding covering.

By using an original part, dimensionally and materially identical, directly from the manufacturer of the recoVAIR /4 system, all these risks are prevented in advance, because the part is designed exactly for the given duct diameter, the given connection method and the declared roof pitch range.

Common installation mistakes and how to avoid them

Based on the experience of installation companies, the most common mistakes when installing roof transition pieces for mechanical ventilation with heat recovery systems concern mainly these points:

1. Incorrect placement relative to eaves and valleys - a transition piece placed too close to a valley is exposed to increased rainwater flow across the roof. The solution is to place it on a "clean" area of the roof plane according to the covering manufacturer's recommendations.
2. Underestimating the height of the chimney cap/finishing piece above the roof - insufficient height risks snow being blown directly into the intake/exhaust ducting in winter.
3. Missing or incorrectly applied sealing strip - for sheet metal or tile coverings, the sealing system recommended by the manufacturer of the specific covering must be used; the universal EPP transition piece collar alone does not replace the roof waterproofing.
4. Not considering the direction of air flow during design - the intake and exhaust passages should be sufficiently far apart to avoid re-intake of already used air (so-called short-circuit flow).

Controlled ventilation with heat recovery - broader context

Vaillant recoVAIR /4 central units operate on the principle of balanced ventilation - they simultaneously extract stale air from "wet" rooms (bathroom, toilet, kitchen) and supply fresh filtered air to living rooms (bedrooms, living room, children's rooms). A highly efficient cross-flow or counter-flow heat exchanger in the unit transfers heat from the outgoing air to the supply air with an efficiency that, in high-quality units, can reach around 90-98%, significantly reducing heat losses caused by conventional window ventilation. This is precisely why the quality and tightness of the entire ducting - including roof passages - is one of the decisive factors of the actual operating efficiency of the system in a real building, not just in the catalogue parameters of the unit itself.

Frequently Asked Questions

Shipping and packaging

Due to the dimensions and shape of the roof collar, this product, given its bulkiness and fragility, is not shipped via parcel lockers/pickup boxes - it is delivered exclusively by courier directly to the address, in order to prevent damage to the shape of the sleeve during transport and handling.