Tight window installation – why do SIGA tapes, EPDM, and milled foundations make a difference?

4.1.2026

High-quality windows will not fulfill their role without proper installation. It is the tight installation that determines the durability of the joinery, thermal comfort, and real energy savings. At Vindue, we use system solutions: SIGA tapes, EPDM insulation, and milled foundations for specific profiles, because only this approach allows us to offer a 20-year warranty.

What is airtight window installation?

Airtight installation is a window installation technology that:

  • eliminates thermal bridges,
  • protects the insulation layer from moisture,
  • provides controlled water vapor flow,
  • increases the durability of the entire structure.

Unlike "foam-only" installation, airtight installation is based on three protective layers:

  1. outer layer – vapor-permeable,
  2. middle layer – insulating,
  3. inner layer – vapor-proof.

SIGA vapor-proof and vapor-permeable tapes – moisture control

At Vindue, we use tapes from the renowned SIGA brand, which ensure long-lasting tightness of the connections between the window and the wall.

Why are tapes more important than foam itself?

  • Assembly foam insulates but does not protect against moisture.
  • without tapes, foam loses its properties,
  • Moisture leads to cooling, mold, and degradation of the assembly.

What are the benefits of SIGA tapes?

  • air tightness,
  • durability measured in decades,
  • stability of thermal insulation parameters,
  • structural safety.

EPDM – effective insulation of the critical zone

The bottom part of the window is the most vulnerable to:

  • rainwater,
  • snow,
  • dampness.

Why is EPDM important?

EPDM insulation:

  • are resistant to weather conditions,
  • do not lose their flexibility,
  • effectively protect the lower part of the assembly.

At Vindue, we use EPDM as a complement to our airtight installation system, not as an optional extra.

Milled foundations for profiles – the basis for permanent installation

We do not use universal solutions. Each foundation is milled to a specific window profile, which ensures:

  • perfect fit,
  • stable load transfer,
  • elimination of thermal bridges,
  • better tightness of the entire connection.

Why is it better than standard foundations?

  • no assembly clearance,
  • window not working in time,
  • longer service life of woodwork.

Why is it important to have your own installation team?

A tight installation requires:

  • experiences,
  • precision,
  • knowledge of systems.

In Vindue:

  • we do not use subcontractors,
  • we work according to a single standard,
  • we are responsible for the entire implementation.

That's why we can offer a 20-year warranty.

Summary – airtight installation is an investment, not a cost

Tight installation using:

  • SIGA tapes,
  • EPDM insulation,
  • milled foundation beams,

these are real benefits:

  • lower heating bills,
  • no moisture problems,
  • durability for years,
  • investment security.


Are you planning to replace or install windows?

Contact us and learn about Vindue's airtight installation standard.

Back to news