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Müller & Sohn — Window Cleaning Guide

🇩🇪 Germany · Last reviewed by Justin Orloff

Muller und Sohn windows

Brand at a Glance

  • Founded: 1911
  • Generation: 5th generation family business
  • HQ: Germany
  • Primary materials: Wood, wood-aluminium, uPVC, aluminium -- 30+ profile systems
  • Official website: mueller-fensterfabrik.de

Product Range

  • Timber windows
  • Wood-aluminium windows
  • uPVC windows
  • Aluminium windows

Why This System

Five generations of German family manufacturing since 1911 -- craft-level quality across all material types. Over 30 profile systems across four material categories -- one of the broadest ranges of any German window manufacturer. Wood-aluminium combination requires a specific cleaning approach that differs from pure timber or pure aluminium. Long-standing family business with regional reputation -- often found in quality residential new-build and renovation projects.

Mueller und Sohn installations span a wide material range. Correctly identifying the frame material before cleaning is essential -- the cleaning solution suitable for timber is different from what you apply to uPVC or aluminium, and wood-aluminium combination requires the most careful handling of all.

Step 1 of 2: Manufacturer Recommendations

Official Care Guidance

No official guide published. The steps below are based on Justin Orloff's 25 years hands-on experience with this system.

Step 2 of 2: The Orloffs Protocol

The Orloffs Protocol

This is how I clean Müller & Sohn windows. The tools and technique below come from 25 years of daily professional work on the glass. Every step has been tested on real installations and adapted specifically for Müller & Sohn systems.

Pro Tools

My daily tool list. This is what I carry to every job.

1Microfiber T-bar applicator, kept clean and rinsed regularly to prevent grit
2Professional squeegee with a fresh rubber blade
3Extension pole for glass above arm height
4Bucket with at least 10 litres of water and enough soap for cleaning power without excess foam
5100% cotton towelling rags for edge detailing
6Vacuum for sill tracks and base profiles

Follow these steps in order. Each one builds on the last. This is the same sequence I use on every Müller & Sohn installation.

  1. 1

    Preparation -- before any water touches the glass

    Fill the bucket with at least 10 litres of water. Add soap for cleaning power -- enough to cut through environmental deposits, not so much you are fighting foam.

    Before touching the glass, brush down the surface to remove loose dust, spiderwebs, and debris. Any grit left on the glass during the wash phase risks scratching during agitation.

    Check the aluminium frame condition before you start. Confirm which cleaning product is safe for that surface before opening any bottle.

    Cover anything below the windows that cannot be moved.

  2. 2

    Agitation -- apply and work the solution

    Dip the microfiber T-bar completely into the soap water, both sides. Remove excess water with your hand so it does not drip. Apply the solution across the entire glass surface with overlapping passes.

    The goal is to fully dissolve and release every deposit from the glass surface. Anything not released during agitation gets transported across the glass by the squeegee as a smear.

    For stubborn spots -- insect marks, salt residue, environmental deposits -- re-apply soap water and allow it to soak for a full minute before agitating again. Use more soap water, not more pressure.

    For panels above arm reach: attach the T-bar to an extension pole. Work in sections -- top first, then middle, then bottom -- keeping each section wet until you squeegee it.

    Rinse the T-bar cover regularly during the job. A dirty applicator causes microscopic scratches that accumulate over time.

  3. 3

    Detail the frame edge before squeegeeing

    Use your 100% cotton towelling rag, finger pressed into the fabric, to work into every junction and remove pooled soap water before the squeegee pass.

    This prevents drips running down onto already-cleaned areas during squeegeeing and keeps soap water out of drainage channels.

    On Mueller Sohn aluminium frames, pay particular attention to the bottom edge where glass meets the frame sill -- water pooled here runs into drainage openings and leaves residue over time.

  4. 4

    The squeegee

    Tilt the squeegee at a slight angle so soap water spills from one side of the channel only -- not both. If the rubber is jumping or squeaking, either the rubber is not lubricated enough or the glass surface has warmed.

    Cutting in: start with the rubber blade making first contact on a dry edge of the glass.

    Side to side: horizontal passes across the panel. Works well on wide sections. Top to bottom: vertical passes down the panel. Works well on tall narrow sections.

    The J tune: one smooth unbroken motion top to bottom, wrist rotating at each end to reverse without lifting the rubber. The most efficient method on larger panels -- but it requires training before applying it to premium glass.

    Wipe the rubber dry after every pass. Overlap each stroke by 2-3 cm.

  5. 5

    Final edge detailing

    After squeegeeing, there is always a residual line of water along the bottom edge and at the panel sides. Take a dry cotton rag, fold to a clean corner, and detail these edges in one smooth pass.

    On Mueller Sohn frames, the bottom edge where glass meets the sill requires the most careful attention. Water left here runs into drainage and leaves residue that affects the next clean.

    Rotate the rag to a clean section after every pass. If the rag picks up grit at any point, replace it immediately.

  6. 6

    Frame wipe and hardware check

    On Mueller Sohn powder-coated aluminium frames: use pH-neutral cleaner only, never abrasive pads or steel wool. Dry immediately after wiping.

    Check that all drainage openings are clear and unobstructed. Water must be able to flow freely -- a blocked channel leads to accumulation that affects seal performance over time.

    Operate every opening window through its full range. Stiff handles or resistance at locking points indicate hardware that needs lubrication. Flag it to the owner rather than forcing it.

Watch the Window Cleaning Manifesto hereSee these techniques in action. Free, 5 minutes, lifetime access.

What NOT To Do

  • Do not apply timber-specific cleaners to aluminium-clad exterior faces.
  • Do not leave timber frames wet -- dry immediately after cleaning.
  • Do not use solvents on uPVC or aluminium.
  • Do not use abrasives on any surface.
  • Do not clean in direct sunlight.

Bundle Kits and Tool Recommendations

Bundle Kit

Orloffs Squeegee Pro Pack flat lay
Pro KitThe full professional setup. Brass squeegees, T-bar with applicator cover, tool belt, rags, soap, and bucket. Everything from the daily tool list in one box.Shop now
Orloffs Squeegee Pro Pack bundled

Cleaning Frequency

Clean every 4–8 weeks depending on environment.

Frequently Asked Questions

How often should I clean Müller & Sohn windows?
For Müller & Sohn windows, we recommend cleaning twice a year depending on your local environment. Coastal or urban locations may need more frequent cleaning.
What tools do I need for Müller & Sohn windows?
Professional cleaning of Müller & Sohn windows requires my daily tool list of: Microfiber T-bar applicator, kept clean and rinsed regularly to prevent grit, Professional squeegee with a fresh rubber blade, Extension pole for glass above arm height, Bucket with at least 10 litres of water and enough soap for cleaning power without excess foam, 100% cotton towelling rags for edge detailing, Vacuum for sill tracks and base profiles.
What should I avoid on Müller & Sohn windows?
Do not apply timber-specific cleaners to aluminium-clad exterior faces.
Does Müller & Sohn publish an official cleaning guide?
Müller & Sohn has not published an official cleaning guide. The protocol on this page is based on Justin Orloff's 25 years hands-on experience.
Can I use a water-fed pole on Müller & Sohn windows?
Yes, purified water via a water-fed pole is one of the safest methods for Müller & Sohn glass. Ensure TDS is at or near zero before use and avoid directing high-pressure water at seals or gaskets.

Field Notes

Mueller und Sohn products are found in quality German residential and commercial buildings. On wood-aluminium combinations, take care to clean interior and exterior faces with the correct material-appropriate approach -- the junction between the timber inner and aluminium outer is where moisture issues develop if cleaning is sloppy.

Justin Orloff