Skip to content
tostem logo

Asia-Pacific Β· Window Manufacturer

TOSTEM β€” Window Cleaning Guide

πŸ‡―πŸ‡΅ Japan Β· Last reviewed by Justin Orloff

tostem windows

Tostem window systems

Quick Facts

founded

1967

hq

Tokyo, Japan (now LIXIL group)

primaryMaterials

Powder-coated aluminium sash profiles

glazingPartner

AGC, NSG specified per project

marketTier

Mass Market Residential

Brand at a Glance

  • Country: Japan
  • Founded: 1967
  • Parent company: LIXIL Corporation (since 2011)
  • Primary material: Powder-coated aluminium sash
  • Market position: Japan's dominant residential window brand
  • Product types: Sliding sash, casement, fixed, and tilt windows
  • Climate context: Japan - humid summers with mould risk in tracks, cold winters, UV chalking on south/west elevations

Product Range

  • Sliding aluminium sash (引き違いηͺ“)
  • Casement sash (ηΈ¦γ™γΉγ‚Šε‡Ίγ—ηͺ“)
  • Fixed windows (FIXηͺ“)
  • TOSTEM composite windows

Why This System

TOSTEM sliding sash tracks are the primary maintenance point on every Japanese residential job. The two-track aluminium channel collects a specific combination of dust, insect matter, and organic debris at the inner corners. Japan's humid summers cause this accumulation to set hard if not cleared regularly. Hard corner grime requires a brush, not just a wipe. TOSTEM powder coat is durable but not immune to Japan's UV loading. South and west-facing elevations on older TOSTEM sash show chalking - the white residue that indicates UV degradation of the coating's outer layer. This is a cosmetic and protective issue, not a cleaning one. Document it, do not attempt to scrub it off. TOSTEM windows are found across every age of Japanese residential building. Older stock from the 1970s and 1980s uses thinner, simpler powder coat. Post-2000 TOSTEM uses improved coatings. Treat older windows with more caution on abrasion.

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

Since 1999 I've cleaned hundreds, if not thousands, of different window brands and systems. The physics of clean glass don't change from one brand to the next. Follow the steps below and you'll clean your TOSTEM windows to a professional standard β€” guaranteed.

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 TOSTEM 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 TOSTEM 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 TOSTEM 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 TOSTEM 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.

Pro Tips

  • Carry two track brushes on Japanese residential jobs - one for upper tracks, one for lower. Cross-contaminating upper and lower track grime spreads mould spores between channel levels
  • When the TOSTEM sash is removed from its track for cleaning (older buildings with removable sash), clean the track fully before replacing - this is the only chance to reach every corner
  • In apartment buildings with many identical TOSTEM windows, develop a track-cleaning rhythm: brush all tracks dry first across the whole floor, then clean glass and frames. This is faster than finishing each window individually

What NOT To Do

  • Do not wet TOSTEM sliding tracks before brushing - wet grime becomes abrasive paste in the track channels
  • Do not use metal implements to clear weep holes in powder-coated track channels
  • Do not use abrasive pads on powder-coated sash frames
  • Do not attempt to scrub powder coat chalking off older TOSTEM sash - this removes the remaining UV protection
  • Do not pressure wash directly into sash track channels or weep holes
  • Do not use solvent-based products on composite TOSTEM resin profiles

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 β†’
Orloffs Squeegee Pro Pack bundled

Cleaning Frequency

Clean every 4–8 weeks depending on environment.

Frequently Asked Questions

How often should I clean TOSTEM windows?
For TOSTEM 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 TOSTEM windows?
Professional cleaning of TOSTEM 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 TOSTEM windows?
Do not wet TOSTEM sliding tracks before brushing - wet grime becomes abrasive paste in the track channels
Does TOSTEM publish an official cleaning guide?
TOSTEM 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 TOSTEM windows?
Yes, purified water via a water-fed pole is one of the safest methods for TOSTEM glass. Ensure TDS is at or near zero before use and avoid directing high-pressure water at seals or gaskets.

Field Notes

β€œTOSTEM track cleaning is the job within the job on every Japanese residential clean. Budget time for it - the corners of a neglected sliding sash track take five to ten minutes per window to clear properly. Japan's rainy season (tsuyu) runs June to July. After prolonged rain, inspect all weep holes on TOSTEM sash - the combination of rainfall and high humidity blocks drainage faster than in any other season. On older TOSTEM sash from the 1980s and 1990s, inspect the sash rollers when the track is clear. Rollers on this generation of product can be adjusted with a cross-head screwdriver via an access hole at the bottom of the sash. A roller riding on grit debris will show a flat spot. Flag this to the property manager. Powder coat chalking on south and west-facing TOSTEM sash is extremely common across older Japanese housing stock. Document it at first visit and include it in your condition report. Do not attempt to remove it with cleaning products - you are removing what remains of the UV protection.”

Justin Orloff