Why External Window Tape Is Just as Important as the Window Itself
Windows are one of the biggest sources of heat loss in a home — and not only because glass lets cold through. Problems often start right at the joint between the window and the wall. That's where rain gets in, where moisture accumulates, and where foam eventually starts to break down. And that's exactly where the Alenor external window tape with full-width adhesive coverage comes to the rescue.
What actually happens without external window tape?
The installation joint between the window frame and the wall is usually filled with polyurethane foam. Foam is excellent for thermal insulation — but it has one serious weakness: it's sensitive to moisture and UV radiation. Without additional protection:
Rain and moisture soak into the foam and damage it
Sunlight accelerates foam degradation — it becomes brittle and loses its properties
Wind drives cold air through the unprotected joint
Over the long term, mould, mildew, and cold bridges form
The result? Windows start to "sweat," moisture appears in the apartment, and heating bills climb.
Alenor external window tape: a solution that works
The Alenor external window tape with full adhesive coverage is a professional waterproofing tape designed specifically to solve this problem. It creates a reliable barrier from the outside — protecting the installation joint from rain, moisture, wind, and UV rays.
What the tape does:
Protects the foam from outside moisture — the tape seals the joint airtight, preventing rain and atmospheric moisture from getting in. The foam retains its insulating properties for years.
Lets moisture escape from inside to outside — this is an important nuance. The tape is vapour-permeable, meaning that if moisture from inside the room reaches the joint, it can escape outward. Moisture doesn't accumulate, so there's no mould risk.
Withstands UV radiation — Latvia's sun and temperature swings (-30°C in winter and +35°C in summer) are far from gentle. Alenor's tape is engineered to last for years under these conditions.
Ready to use right away — no special tools required. The full adhesive coverage (across the entire width of the tape) ensures easy, secure application — the tape bonds evenly and reliably.
Technical composition
The tape is made of three layers:
A synthetic non-woven membrane material — a durable base layer
Pressure-sensitive adhesive with permanent bonding properties — ensures a stable bond
A protective film — removed before application
Unlike standard tapes, here the adhesive covers the entire width of the tape — there are no unprotected strips, no weak spots. Technically, this product is classified as a diffusion-permeable window sealing tape — one of the most searched-for categories of window mounting tapes in Latvia, since it combines waterproofing with vapour release.
Available sizes
Width 70 mm, length 25 m — standard window installation Width 100 mm, length 25 m — wider joints and doors Width 150 mm, length 25 m — large windows and passive houses
Passive house standard
If you're building or renovating to the passive house standard, Alenor's external window tape meets this technology's requirements. In passive houses, every bit of heat loss counts — and protecting the installation joint is one of the mandatory steps for reaching energy consumption targets.
Why choose Alenor?
Alenor is a Latvian company specialising in insulation materials and mounting tapes. Products are available both to professionals — builders, window installers, renovation companies — and to private customers who care about quality workmanship.
Using Alenor's external window tape together with the internal window tape gives you a complete three-layer joint protection system: vapour barrier on the inside, foam in the middle, wind and water barrier on the outside.
Summary
Windows are an investment made for 20–30 years. For that investment to pay off, window installation needs to be done correctly — and that includes proper joint protection. Alenor's external window tape is a simple, proven solution that protects your walls, foam, and indoor climate — both today and ten years from now.
Read also: Window mounting tapes — how to properly insulate windows and save on heating bills.
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