Welche Aufgabe hat eine Unterspannbahn?

Eine Unterspannbahn hat die Aufgabe, Dein Dach vor Feuchtigkeit und Wind zu schützen. Sie wird zwischen der Dacheindeckung und der Wärmedämmung verlegt. So verhindert sie, dass Regen, Schnee oder Staub in die Dämmung eindringen und Schäden verursachen. Gleichzeitig lässt sie aber Wasserdampf aus dem Inneren des Hauses entweichen, um Schimmelbildung zu vermeiden. Eine gute Unterspannbahn sorgt also dafür, dass Dein Dach langlebig und energieeffizient bleibt.

Wo wird die Unterspannbahn befestigt?

Die Unterspannbahn wird direkt auf den Sparren befestigt. Dabei wird sie meist von oben nach unten in Bahnen verlegt. Wichtig ist, dass sie straff gespannt wird, um das Eindringen von Feuchtigkeit zu verhindern. Die Befestigung erfolgt oft mit speziellen Tackerklammern oder Nägeln. Achte darauf, dass die Überlappungen zwischen den Bahnen ausreichend sind, um einen guten Schutz zu bieten.

Was tun bei defekter Unterspannbahn?

Wenn Deine Unterspannbahn defekt ist, solltest Du schnell handeln, um Schäden am Dach zu vermeiden. Zuerst musst Du die schadhafte Stelle finden und dann überlegen, ob eine Reparatur möglich ist oder ob ein Austausch nötig wäre. Bei kleineren Rissen kann oft spezielles Reparaturband helfen. Wenn größere Schäden vorliegen oder die Unterdeckbahn schon älter ist, ist ein Austausch ratsam.

ProLine 150 Roof and facade membrane

Quantity	Unit price	Base price
To 4	€142.60	€1.90 / 1 m²
To 8	€135.80	€1.81 / 1 m²
From 9	€129.00	€1.72 / 1 m²

Prices incl. VAT

20 Reviews

Driving rain proof
Open to diffusion
Integrated self-adhesive seam

Execution

1.5m x 10m

1.5m x 25m

1.5m x 50m

Total:

Roll

Product number: SW10001.2

Available variants

Preview	Product number	Execution	Content	Unit price	Buy

Driving rain proof
Open to diffusion
Integrated self-adhesive seam

Product advantages

UV-resistant

Long-term protection

Open to diffusion

Prevents mold growth

Driving rain proof

Waterproof, protection from rain

✓

EASY TO INSTALL

With a surface weight of 150g/m² and double self-adhesive strips (SK), ProLine 150 is safe and quick to install.

✓

EXTREMELY OPEN TO DIFFUSION

The water vapor-permeable special membrane allows the insulation to dry out optimally and prevents mold growth.

✓

VARIABLY APPLICABLE

The ALMO underlay can also be used as a façade membrane for closed facades.

✓

APPLICABLE FROM ROOF PITCH > 10°

The ProLine 150 is versatile and can be used for roof pitches from 10°.

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VERY TEAR RESISTANT

The three-layer construction with 2 nonwovens on the outside and a special membrane makes the ProLine 150 very tear-resistant.

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A-CLASSIFICATION

The ALMO ProLine 150 complies with the ZVDH classification UDB-A / USB-A.

Technical data

Application	Underlayment
Features	Self-adhesive seam, open to diffusion
Carrier system	Polypropylene fleece
Functional layer	Microporous functional film
Grammage	150 g/m²
Roll dimensions	50m x 1,5m
Diffusion-equivalent air layer thickness (sd value)	0,02 m
Roof pitch	10°
Maximum tensile force longitudinal / transverse in N / 50mm	315/225
m² per roll	75
UV resistance	3 months
Suitability as temporary covering	4 Weeks
Temperature resistance	-40 °C to +80 °C
Fire classification	Class E (according to EN 13501-1)
Resistance to water penetration	W1 (according to DIN 1928)

Installation instructions for ProLine roof & facade membranes

Step 1: Align and prepare the roof membrane

The ALMO ProLine sarking and underlay membrane should be laid starting at the lower part of the roof pitch and parallel to the eaves. The printed side is the upper side and faces the installer during installation. The membrane is rolled out directly onto the rafters or onto the fully sheathed roof. The underlay should protrude slightly after positioning.

Step 2: Fastening in the eaves area

In the eaves area, the roofing membrane must be fastened under the counter battens on the eaves sheet or above the eaves batten on the gutter lashing. At the same time, water pockets and counterfalls should be avoided. Fasten the underlays to the rafters with nails or staples.

Step 3: Nail sealing tape and counter battens

To keep the rafters watertight, we recommend using a strip of our Nail sealing tape 60 under the counter battens. After spreading the membrane, counter battens and battens should be attached. The counter battens create a gap between the membrane and the battens. Make sure that all points where nails or staples pass through the membrane are sealed with nail sealing tape and are located under the counter battens.

Step 4: Overlap and bond the roofing membranes

Another strip of membrane should be applied with a 10-15 cm overlap. To make the installation of the roofing membrane efficient, avoid draughts and keep the overlaps watertight, use the adhesive strips integrated with the membrane, which are glued together.

Step 5: Ridge sealing

For non-ventilated roof constructions, the membrane goes over the ridge to seal it against snow and rain. For ventilated roof constructions, the roof membrane should be approx. 5 cm from the highest ridge point. This ventilation opening should also be secured with a strip of roofing membrane fixed over a counter batten so that the membrane overlaps the roof surface by approx. 20 cm.

Step 6: Sealing for eaves

In the case of roof projections such as chimneys, the sheets should be cut, pulled out and fixed with the ALMO Versa Uni Tape be sealed. Separate strips of membrane are bonded to the surface and at the corners. An inclined foil gutter can be installed above penetrating building components. To form a temporary covering, connections to rising building components must be additionally bonded and secured to prevent them from running behind.

Step 7: Seal overlaps windproof

The resulting overlaps must be bonded laterally and transversely if wind-tightness is required. For a replacement overlap, the membrane strip of a foil gutter is extended to below the next ridge-side height overlap and taped all the way around. The open joints at the corners are taped to make them rainproof. Roof windows are integrated into the opening and fixed in place. If counter battens or the resulting frame are further away from the window, separate strips of membrane can be attached.

Step 1: Aligning the facade membrane

The smooth side of the Volcano® UV facade membrane should face outwards and the ProLine with the lettering should face the installer. It should be attached directly to the insulation using a stapler above the adhesive seam.

Step 2: Overlapping the facade membranes

The second facade sheet should be installed over the first facade sheet, with an overlap of around 10 cm. The self-adhesive strips of the two façade membranes should then be detached and glued closely together to ensure a tight facade seal.

Step 3: Sealing with Volcano® UV adhesive tape

The facade membranes should be overlapped using the UV-stabilized and diffusion-open Volcano® UV Facade adhesive tape for an optimal, wind-tight seal.

Step 4: Installing the counter battens

After the facade sheets have been bonded, the counter battens should be mounted directly onto the supporting structure in the direction of the supporting structure.

Step 5: Fastening the timber cladding

The timber cladding is then mounted directly onto the counter battens. It is important to fasten the timber cladding evenly and securely in order to create a stable base for the facade cladding.

Carrier system:	Polypropylen-Vlies
Application:	Underlayment / sarking membrane
Characteristics:	Self-adhesive seam, Diffusion open
Functional layer:	Microporous functional film
Weight per unit area:	150 g/m²
Diffusion-equivalent air layer thickness (sd value):	0,02m
Maximum tensile force longitudinal / transverse in N / 50mm:	315/225
Roll length:	50m
Width:	1,5m
m² per roll:	75
Suitability as a makeshift cover:	4 Weeks
UV-resistance:	3 months
Temperature resistance:	-40 °C to +80 °C
Fire behavior:	Class E (according to EN 13501-1)
Widerstand gegen Wasserdurchgang:	W1 (nach DIN 1928)

Downloads

Data sheet_ProLine 150

Use for this

Use with

ALMO TwinTape double-sided adhesive tape

Airtight installation without stapling
Double-sided strong adhesive
Tear-resistant liner

Product advantages

Gluing instead of stapling

Airtight installation without staple cracks

Tear-resistant liner

Time saving

Double-sided extreme adhesive strength

Quick & easy installation

✓

THE PERFECT ALTERNATIVE TO STAPLING

Thanks to its double-sided adhesive surface, ALMO TwinTape provides a strong, airtight seal that replaces conventional stapling and ensures even, clean installation without damaging the vapor barriers or connections.

✓

HIGH ADHESIVE STRENGTH FOR RELIABLE SEALING

Thanks to the high-performance adhesive, the double-sided adhesive tape guarantees permanent and secure fixing of vapor retarders and connections.

✓

EASY HANDLING THANKS TO TIGHT LINER

The tear-resistant plastic liner enables uncomplicated and precise processing of the tape, even with difficult joints.

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EXTREMELY RESISTANT TO AGEING

The high-performance adhesive does not dry out and remains stable for a long time without becoming brittle.

✓

TEMPERATURE-RESISTANT AND DURABLE

The double-sided adhesive tape is designed for extreme conditions - it remains fully functional even at temperatures from -40°C to +100°C and retains its adhesive strength permanently.

Technical data

Adhesive	Modified dispersion acrylate
Carrier system	Grid-reinforced LDPE foil
Coverage	Tear-resistant plastic liner
Roll length	50m
Width	20mm
Temperature resistance	-40 °C to +100 °C
Processing temperature	-5 °C to +40 °C

(4)

Content: 2 RL (€15.77 / 1 RL)

From €12.85

Buy now

ALMO Eco Tape 50 adhesive tape

Extreme adhesive strength
Stretchable
For the interior

Product advantages

For indoor use

Airtight bonding & sealing

Simple installation

Time saving

Strong adhesive strength

High quality

✓

EXTREME ADHESIVE STRENGTH AND FLEXIBILITY

Permanent airtight sealing of vapor retarders, roof and façade membranes for indoor use. Ideal for overlaps, connections and repairs.

✓

HIGH AGEING RESISTANCE

The high-quality acrylic adhesive ensures that the high-performance tape is securely anchored over a long service life. Moisture-resistant and durable.

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FREE FROM RESIDENTIAL TOXINS

Our ALMO Eco Tape 50 is free from solvents, chlorine and formaldehyde.

Technical data

Carrier system	Grid-reinforced LDPE film
Adhesive	Modified dispersion acrylate
Coverage	Silicone paper
Roll length	25m
Width	50mm
Temperature resistance	-40 °C to +100 °C
Processing temperature	-5 °C to +40 °C

(7)

Content: 2 RL (€15.77 / 1 RL)

From €11.50

Buy now

Topseller

Versa® Black Uni Tape 60

Extreme adhesive strength
Extremely UV-stable
Flexible and stretchable

Product advantages

UV-resistant

Long-term protection

Tear-resistant liner

Time saving

High adhesive strength in cold & heat

High quality

✓

EXTREMELY UV-STABLE AND WATERPROOF

Our ALMO adhesive tape is specially UV-stabilized to provide long-lasting protection and remains completely waterproof even under extreme weather conditions.

✓

STRETCHABLE AND STRONG ADHESION

Developed to adhere strongly even at temperatures from -40°C to +100°C. The high elongation and flexibility enable a windtight seal outdoors, ideal for all climatic conditions.

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QUICK AND EASY INSTALLATION

Thanks to the unique, tear-resistant cover liner, the tape is easy to work with, perfect for demanding overlaps and overhead work.

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HIGH PERFORMANCE WITH A LONG SERVICE LIFE

The high-quality acrylic adhesive guarantees permanent anchoring and resistance to ageing, ensuring reliable use for years to come. The adhesive tape is also moisture-resistant.

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MADE IN GERMANY – QUALITY GUARANTEE

Manufactured to the strictest German quality standards, our ALMO Versa Black UV adhesive tape comes with a 10-year guarantee that promises the highest quality and reliability.

Technical Data

Application	Adheres to wood materials, plasterboard materials, metal, roof and façade membranes
Features	Tear-resistant liner
Carrier system	Grid-reinforced LDPE film
Adhesive	Modified dispersion acrylate
Coverage	Tear-resistant plastic liner
Roll length	25m
Width	60mm
Temperature resistance	-40 °C to +100 °C
Processing temperature	-5 °C to +40 °C

(14)

Content: 2 RL (€20.59 / 1 RL)

From €21.10

Buy now

Versa® Uni Tape 100 50/50 adhesive tape

Extreme adhesive strength
Tear-resistant, slit separating strip
For inside and outside

Product advantages

For inside and outside

Versatile application

Tear-resistant liner

Time saving

High adhesive strength in cold & heat

High quality

✓

EXTREME ADHESIVE STRENGTH AND FLEXIBILITY

Durable airtight and windproof sealing of vapor retarders, roof and façade membranes for interior and exterior use. Ideal for overlaps, connections and repairs.

✓