Description
Blue Dolphin breathable seam tape is a specially designed building product developed especially for joining and repairing breathable roofing underlays and other polypropylene-based (PP) nonwoven materials. The key feature of the product is its high vapour permeability (approx. 3000 g/m²/24h), which ensures that any moisture that has got into the structures can evaporate through the taped seam, preventing the risk of moisture damage. This makes it a critical component in modern, energy-efficient construction, where airtightness and breathability of structures at the same time are key.
The backing of the tape is a durable polypropylene nonwoven, black in colour, which blends in visually with most underlay materials. The total thickness of the tape is 0.60 mm (+/- 5%), which makes it firm enough to withstand stresses during installation but flexible enough to conform to unevenness in the substrate. Its tensile strength is over 100 N/25mm, which gives reliable structural integrity at the seams.
The tape uses a high-quality acrylic adhesive. This type of adhesive was chosen for its excellent initial adhesion and long-term durability. Adhesion to steel is over 10 N/25mm, which indicates a strong bond to most building materials. The adhesive is designed to withstand changing weather conditions, including rain, moisture and UV radiation, which makes it a reliable choice for site conditions before the final roofing material is installed.
The product is designed to meet the requirements of professional builders, offering a reliable solution for sealing the building envelope. Its uses range from new construction to renovation projects where the integrity of vapour barriers and underlays must be reliably ensured without compromising the moisture performance of the structure.
Intended use:
Blue Dolphin breathable seam tape is a versatile solution for various sealing needs in construction. Its main uses are listed below:
- Seaming roofing underlays: Used for taping the overlaps of breathable roofing underlays under the roof covering. This ensures the roof is watertight while allowing moisture to escape from the structures.
- Joining vapour barrier fabrics: Suitable for sealing the seams of breathable vapour barriers and air barrier fabrics (which are PP-based) in wall and roof structures.
- Repair work: An excellent solution for quick, durable patching of tears, holes or other damage in roofing underlays or wind barrier fabrics on site.
- Sealing penetrations: Can be used to seal the joints of various penetrations (such as pipes and ventilation ducts) to the roofing underlay or wind barrier, as long as material compatibility has been checked.
Package contents:
The pack contains one roll of black Blue Dolphin breathable seam tape. The roll dimensions are 50 mm (width) x 25 m (length).
Features:
This tape offers a range of technical properties optimised for demanding construction use:
- High vapour permeability: A permeability value of about 3000 g/m²/24h ensures that the tape does not form a vapour-tight barrier, allowing structures to dry out.
- Strong acrylic adhesive: Gives excellent adhesion, especially to nonwoven surfaces, and keeps its properties over a wide temperature range.
- PP nonwoven backing: The material is chemically compatible with most roofing underlays on the market, which guarantees a long-lasting joint.
- Weather resistance: The tape withstands rain, moisture and UV radiation, which allows it to be exposed to the weather during the construction phase.
- Good tensile strength: The construction withstands stretching and stress, which stops seams opening as the structures move.
Technical specifications:
The key technical values of the product are listed below:
- Backing: PP nonwoven (polypropylene)
- Adhesive type: Acrylic
- Colour: Black
- Total thickness: 0.60 mm (+/- 5%)
- Adhesion to steel: > 10 N/25mm
- Tensile strength: > 100 N/25mm
- Vapour permeability: approx. 3000 g/m²/24h
- Application temperature: +5°C … +40°C
Instructions for use:
To achieve the best possible result and make sure the seam holds, follow these installation instructions:
First make sure the surfaces to be taped are completely clean, dry and free of dust, grease or other impurities. Moisture or dirt significantly weakens the adhesion of the adhesive. The optimal application temperature is between +5°C and +40°C. If installation takes place in colder conditions, it may be necessary to warm the surfaces.
Unroll the tape and place it in the centre of the seam or damaged area so that it covers both sides of the joint evenly. Press the tape firmly onto the substrate along its whole length and width. Use a rubber roller or spatula, for example, to make sure the adhesive surface activates and adheres tightly to the surface of the nonwoven, removing any air bubbles. Overlap tape joins sufficiently to guarantee tightness.
Store the tape rolls in their original packaging in a dry, cool place, protected from direct sunlight, so that the properties of the adhesive stay optimal.
Warnings:
Although the tape is UV resistant, it is not intended to be permanently exposed to direct sunlight. The taped surface should be covered with the final building material (e.g. roof covering or cladding) within a reasonable time after installation according to the manufacturer’s instructions. Do not use the tape on surfaces that are constantly under water. Always check the compatibility of the tape with materials that are not PP-based before large-scale use.
Frequently asked questions (FAQ):
What does it mean that the tape is “breathable”?
Breathability means the tape’s ability to let water vapour through. The high vapour permeability value of this tape (3000 g/m²/24h) means that it allows moisture in the structures to evaporate outwards through the tape, which prevents moisture condensing and mould damage, unlike fully airtight tapes.
Can this tape be used for seaming ordinary construction plastic?
This tape is optimised for breathable nonwoven materials. Although it may adhere to ordinary PE construction plastic, its breathable property is wasted on airtight plastic, and adhesion may not be as good as on nonwoven. For ordinary vapour barrier plastic, a dedicated airtight vapour barrier tape is recommended.
How long does the tape withstand the weather before being covered?
The tape is designed to withstand normal site conditions, including UV radiation and rain, during the installation phase. The exact time depends on the conditions, but we recommend covering taped surfaces with the final roof covering or cladding as soon as possible, typically within a few months of installation.
Recycling instructions:
Used tape should be disposed of as mixed waste. The core of the tape roll and any packaging cardboard can be recycled in cardboard collection.
