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© 2026 cohaga AG · All Rights Reserved · St. Gallen, Switzerland · Imprint745,701 companies indexed · Last updated: today
DirectoryCrafts & TradesRoofingLangnau Am AlbisProof GmbH
Proof GmbH Logo
Verified· 3 sourcesTrust Score
Summary

About the company

The core activity of Proof GmbH is roofing and sheet metal work, particularly in the overall renovation and renovation of roofs, including those of historical significance and under home or monument protection, as well as in the new construction of roofs. This also includes specific work such as sheet metal work, roofing work, liquid sealing, pitched roofs, flat roofs, green roofs, metal, shingle or natural stone facades, renovations and lightning protection systems.

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Offering

Products & services

Industry:RoofingSheet Metal Work
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Proof GmbH

✓ Offered12
Comprehensive roof renovation and restoration
Comprehensive roof renovations for historic and new buildings, from dismantling through new construction to ancillary work; also restorations and energy-efficient roof refurbishments.
Sheet-metal work
Gutters, downpipes, copper cladding, standing-seam roofs, sheet-metal façades, chimney flashings, lightning protection systems and custom-made solutions for new builds and listed properties.
Roofing work
Roofing work for pitched and flat roofs, from the timber frame up to the finished roof, including new builds, renovations and maintenance work.
Flat roof renovations
Renovations of flat roofs, including projects with green roof systems and terrace refurbishments, carried out professionally and on schedule.
Pitched roof renovations
Renovations of pitched roofs with thermal insulation, new roof coverings and refurbishments of historic or newer buildings.
New roof construction
Design and construction of new roofs, including execution of roofing and sheet-metal work for new builds.
Liquid waterproofing and cold-applied plastics
Liquid waterproofing membranes and cold-applied plastics for renovations of balconies, terraces and roofs as an alternative waterproofing method.
Façade renovations
Renovations of façades with sheet metal, shingles or natural stone, complemented by sheet-metal façades and timber shingle façades.
Lightning protection work
Lightning protection systems according to standard, including installation and work related to roofing and sheet-metal projects.
Work at height without scaffolding
Work at height on roofs, façade components and windows with a height worker diploma, including at hard-to-reach locations without scaffolding.
Roof maintenance and repairs
General roof maintenance as well as roof service and repairs with or without scaffolding.
Solar systems and photovoltaic installations
Design and installation of photovoltaic, solar and solar thermal systems together with sister company Solproof GmbH.
Trust & reputation

ranQ Trust Score of Proof GmbH: 4.4 out of 5.0

Trust Score4.4/ 5.0

Very high

x

Data basis 96% · As of October 2026

Proof GmbH scores 86.2 out of 100 points in the Reputation area of the ranQ Trust Score. This area carries 42% of the weighting.
x
CriterionValueWeight
  • Review quality: The average rating across all connected sources, smoothed against the industry mean. So 5.0 stars from three reviews do not outrank 4.7 from three hundred.88.724%
  • Review volume: The number of reviews across all sources. The scale is logarithmic: the first reviews count the most, and the maximum is reached at 50 reviews.78.610%
  • Review recency: The age of the most recent review. Two-year-old reviews deliberately sit in the middle, because that is normal for Swiss SMEs. Only after three years without a new voice does the value drop markedly.88.08%
Proof GmbH scores 83.0 out of 100 points in the Substance area of the ranQ Trust Score. This area carries 28% of the weighting.
x
CriterionValueWeight
  • Establishment: Years since founding or brand launch, logarithmic. The maximum is reached at 15 years.100.012%
  • Company size: The headcount band, researched by ranQ or stated by the company. It is scored in steps rather than by head count, because the data only provides bands.55.07%
Proof GmbH scores 83.3 out of 100 points in the Identity area of the ranQ Trust Score. This area carries 22% of the weighting.
x
CriterionValueWeight
  • Verification: Official register entry (commercial register with UID or professional-body record, 55 points), confirmed domain (20 points) and confirmed ranQ profile (up to 25 points, depending on completeness).83.322%
Proof GmbH scores 17.1 out of 100 points in the Visibility area of the ranQ Trust Score. This area carries 8% of the weighting.
x
CriterionValueWeight
  • Website authority: Ahrefs' Domain Rating measures, on a scale of 0 to 100, how strongly a website is linked from other websites. For Swiss SMEs the range up to 40 is typical; the maximum is reached at 35.17.14%
  • Media authority: No data point — the criterion is taken out of the weighting and does not lower the score.—4%
Qualifications+0.00

Proof GmbH reaches a ranQ Trust Score of 4.4 out of 5.0 — rated «Very high». The rating draws, among other things, on 5.0 out of 5 stars from 21 customer reviews. The data basis is 96%, so the score is backed by part of the criteria. As of October 2026.

The Trust Score cannot be bought and is calculated from publicly verifiable data.

Reviews

Aggregated rating

Aggregated rating
5
of 5

Aggregated from 21 reviews across all connected sources

Sources
GGoogle521
★TrustpilotSoon
PProvenExpertSoon

Further sources are added continuously and factored into the ranQ Rating.

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Location

Hier entsteht die Karte
Spinnereistrasse 12 a
8135 Langnau Am Albis
Opening hours
Mon
07:00 - 17:00
Tue
07:00 - 17:00
Wed
07:00 - 17:00
Thu
07:00 - 17:00
Fri
07:00 - 16:00
Sat
Closed
Sun
Closed

At a glance

Legal form
Limited Liability Company
UID
CHE-112.850.655
Founded
2006 · 20 years
Last commercial register change
October 3, 2011
Employees
1 to 10
Legal form: Graded by liability and disclosure. The weight is kept small: a sole proprietorship is not a dubious company, it is just liable differently.
88.0
6%
  • Branch offices: Branch offices linked in the commercial register. Having none is normal and costs no points.70.03%
    • Full methodology

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