#flachdach

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Ask any flat-roof specialist what causes the most construction defects, and they'll tell you the same thing: details. Not big structural failures - small, overlooked connections and transitions that were designed or executed incorrectly. The Attika is one of the most detail-critical zones of any flat-roofed building, and getting it wrong is expensive.

This guide walks through everything you need to know about Attika details - what they are, why they're so important, and how to execute them correctly in 2026.

What Is an "Attika Detail"?

In construction, a detail (Detail) refers to a scaled drawing or specification showing exactly how a particular junction, connection, or transition should be built. An Attika detail shows:

How the roof build-up connects to the Attika wall

How the waterproofing membrane terminates against the Attika

How the Attikaabdeckung (cover plate) sits and drains

Where thermal insulation goes

How drainage and overflow outlets are positioned

Getting these details right is the difference between a dry, energy-efficient building that lasts 50 years and a building with water damage, mold, and expensive remediation bills within 5 years.

The Critical Attika Detail Zones

Zone 1: The Waterproofing Upstand (Abdichtungsanschluss)

This is probably the single most important Attika detail. The flat roof waterproofing membrane must be turned up against the inner face of the Attika wall to a minimum height of 15 cm above the finished roof surface (this is the absolute minimum - 20 cm+ is better practice).

This upstand creates a water-resistant seal that prevents rainwater from working its way behind the membrane and into the wall or structure.

Common mistakes:

Upstand too short (under 15 cm)

Membrane not properly bonded to the Attika face

Membrane termination not protected against UV and mechanical damage

Best practice: The membrane top edge should be terminated with a metal profile (Abschlussprofil) and sealant. It should never be left exposed.

Zone 2: The Attikaabdeckung Connection

The cover plate on top of the Attika (Attikaabdeckung or Attikablech) is the first line of defense against rainwater. The detail here must ensure:

The cover plate slopes away from the building (min. 2%)

The plate overhangs the outer face of the Attika by at least 3–5 cm (Überstand) to throw water clear of the facade

The connection to the Attika wall below is properly sealed

In Germany, the standard overhang (Attikablech Überstand) is specified in DIN standards and local guidelines. Checking the applicable standard for your project is always necessary.

Zone 3: The Inner Attika Face (Innenseite)

The inner face of the Attika (facing the roof area) must be properly integrated with the roof insulation layer and membrane. Cold bridges here can cause condensation and mold on interior surfaces directly below.

With conventional concrete Attikas, significant insulation detailing is required around the base of the Attika to break the thermal bridge. With modern composite systems, this is dramatically simplified.

Zone 4: The Drainage and Overflow Zone

Every flat roof needs at least one emergency overflow (Notüberlauf) per drainage zone. This is typically positioned through or adjacent to the Attika.

The overflow must be:

At least 5–10 cm above the primary drain level but below the waterproofing upstand height

Properly waterproofed where it penetrates the Attika

Sized to handle extreme rainfall events

Forgetting or poorly detailing the Notüberlauf is a common cause of catastrophic roof flooding. In 2026, with extreme weather events becoming more frequent, this detail is more important than ever.

Attika Detail in Timber Construction (Holzbau)

Timber hybrid buildings present specific challenges for Attika detailing. The connection between a timber or CLT wall and the Attika element must:

Allow for timber shrinkage and movement

Prevent moisture from being trapped in the timber structure

Maintain the thermal performance of the timber envelope

Meet fire protection requirements at the roof edge

Prefabricated Attika systems designed for timber construction use specific connection profiles and separation layers to address these challenges. The overtec Attika system includes dedicated details for timber hybrid applications.

How to Read an Attika Detail Drawing

If you've ever looked at a construction detail drawing and felt confused, you're not alone. Here's a quick guide:

Scale - Attika details are usually drawn at 1:10 or 1:5 (ten or five times larger than real life) so small elements are visible.

Layer labeling - Each layer is labeled: roof insulation (Dämmung), waterproofing membrane (Abdichtung), vapor barrier (Dampfsperre), screed (Estrich), structural slab (Decke), etc.

Dimension lines - Look for the waterproofing upstand height (should be ≥15 cm), the Attika wall thickness, and the cover plate overhang.

Connection details - Look at how the membrane terminates, how the cover plate connects, and where the drainage outlet is positioned.

Common Attika Construction Mistakes (And How to Avoid Them)

1. Upstand too low. The membrane doesn't reach 15 cm above the roof surface. Water gets behind the membrane during heavy rain. Fix: always specify and verify upstand height.

2. No thermal break. Concrete Attika conducts heat directly from building interior to exterior. Fix: use insulating materials or composite Attika systems.

3. Incorrect cover plate slope. Water pools on top of the Attika and saturates the wall. Fix: specify minimum 2% slope in every detail.

4. Insufficient overhang. Cover plate flush with facade allows water to run down the building face, causing staining and long-term damage. Fix: minimum 3 cm overhang, 5 cm preferred.

5. No emergency overflow. Primary drain blocks during heavy rain; roof fills with water. Fix: always include Notüberlauf in every drainage zone.

6. Poor joint sealing between Attika elements. Water enters through joints between precast elements. Fix: use proper sealant systems and verify joint details during installation.

Attika Detail With the overtec System

The overtec Attika system comes with a full library of Attika detail drawings for different building types, substrates, and connection scenarios. This includes:

Standard flat roof connections

Timber hybrid (Holzbau) connections

Details for waterproofing integration

Cover plate connection profiles

Emergency overflow integration

All details are based on approved engineering data and the company's European Technical Assessment (ETA22-0221). This is valuable for structural engineers and certifiers who need verified technical backup.

Quick Reference: Attika Detail Checklist

Waterproofing upstand ≥ 15 cm above finished roof surface

Upstand properly bonded and mechanically fixed to Attika face

Upstand top edge protected with metal termination profile

Cover plate slope ≥ 2%

Cover plate overhang ≥ 3–5 cm

Thermal break specified at Attika base

Emergency overflow included and correctly positioned

All element joints sealed

Detail compliant with applicable standards (OIB/DIN)

Overtec

Address: Salzburger Strasse 101 A-4800 Attnang-Puchheim Austria

Email: [email protected]

Website: overtec.com

YouTube: https://www.youtube.com/channel/UCU2H30yAl0CJjyiDbsAxt7Q/videos

LinkedIn: https://www.linkedin.com/company/overtec/

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