Sealing Tapes for Joints and Seams: How to Choose the Right One and Prevent Moisture Ingress
A building's airtightness is one of the main factors affecting both energy efficiency and durability. Even small gaps at joints — around windows, doors, roof pipes, or façade elements — can, over time, cause significant damage: water ingress, heat loss, mould growth, and rotting structures. That's exactly why sealing tapes are an indispensable material in both new construction and renovation.
In this article, we look at the types of sealing tape available, which situations each is best suited for, and how to ensure a joint lasts for years without needing repeated maintenance.
Why is sealing tape better than sealant?
Sealant is the traditional solution for filling seams, but it has several drawbacks. It requires curing time, is hard to apply in places with limited access, and once cured, it can crack if the structure moves even slightly — which always happens due to temperature changes. Sealing tapes are more flexible, faster to apply, and withstand movement without cracking.
Modern sealing tapes, such as those in Alenor's sealing tape range, are made from materials that provide both moisture and air tightness, while retaining flexibility across a temperature range of -30°C to +80°C and beyond.
Types of sealing tape and their applications
Butyl sealing tapes
Butyl-based sealing tapes are ideal for waterproofing tasks — roof seams, façade element joints, and pipe penetrations. Alenor's K-2 double-sided butyl tape is one of the most effective solutions where two materials need to be joined tightly and durably — for example, roof window frames to roof covering, or profile sheet overlaps.
Butyl sealing cord
Not every location is suited to a flat tape — sometimes a gap is irregularly shaped or hard to reach. In these cases, Alenor's butyl sealing cord is an indispensable helper. It's a soft, mouldable strand of butyl material that's pressed into a gap and seals even irregularly shaped surfaces tightly. It's used for sealing window frames, façade elements, and metal structures.
XLPE acoustic insulation and sealing tape
Floor and wall joints are a source not only of moisture but also of noise and heat loss. Alenor's XLPE acoustic insulation tape performs a double function — it protects against capillary moisture penetration while also absorbing impact noise caused by footsteps on the floor. It's especially useful under flooring and at wall/floor joints.
How to choose the right sealing tape
When choosing a sealing tape, several factors need to be considered:
Location. Outdoors (roof, façade) requires UV- and rain-resistant tapes. Indoors (floor joints, walls), less UV-resistant materials can also be used.
Temperature. Near ventilation and heating, heat-resistant tapes are needed. In cold locations, choose tapes with good flexibility at low temperatures.
Surface material. Some tapes bond well to metal but less well to concrete. Check the product specifications or use a contact primer.
Movement compensation. If the joint is subject to movement (thermal expansion, vibration), choose a flexible butyl- or silicone-based tape.
Common mistakes when using sealing tapes
The first and most common mistake is applying the tape to a damp or dirty surface. Many people assume the tape will "stick anyway," but in practice, moisture trapped under the tape eventually causes condensation, and the tape starts to detach. Always make sure the surface is dry and clean.
The second common mistake is insufficient overlap. Professionals recommend overlapping the tape by at least 50–75 mm on each side at joints. A smaller overlap increases the risk that the edge will lift and the joint will lose its airtightness.
The third mistake is not pressing the tape down properly. Even the best tape won't perform correctly if it isn't firmly pressed onto the surface. Use a pressure roller, or at least press firmly by hand, making sure the entire tape surface is in full contact with the base material.
Conclusion
A properly chosen and applied sealing tape can significantly extend the service life of a building's structures, reduce heat loss, and prevent moisture-related damage. Alenor offers a wide range of sealing tapes for various applications — from roof and façade sealing to indoor floor and wall joints.
Browse Alenor's full range of sealing tapes and choose the right solution for your project. If you're not sure which tape is right for your case, get in touch — we're happy to help!