Oknotherm — Window Cleaning Guide

Quick Facts

Brand at a Glance

Product Range

Why This System

Step 1 of 2: Manufacturer Recommendations

Official Care Guidance

Glass

• ✓Lukewarm water with pH-neutral glass cleaner. Microfibre T-bar and professional squeegee.
• ✓Rinse ground-floor windows with plain water before applying cleaning solution to remove road salt deposits.
• ✓Clean inner face in tilt position, outer face in turn position. Full squeegee strokes top to bottom.
• ✓Check glass unit seal condition at each visit - mid-range units with blocked drainage slots fail earlier than correctly maintained windows.

Frames

• ✓PVC frames: pH-neutral cleaner, damp cloth, no solvents. On colour foil profiles, no solvent-containing products under any circumstances.
• ✓White PVC: mild detergent or PVC-specific cleaner. Persistent staining can be treated with specialist PVC restorer - test first on an inconspicuous area.
• ✓Clear all sash drainage slots at the base of each sash after every clean. Use a soft brush or plastic tool.
• ✓Wipe rubber seals with a damp cloth. Do not use silicone spray on rubber seals - it degrades EPDM rubber over time.

Hardware

• ✓Lubricate all hinge scissors, espagnolette rods, and corner transfer pieces annually with light machine oil or PTFE spray.
• ✓Wipe visible hardware with a damp cloth at every clean. Dry immediately to prevent surface rust on steel components.
• ✓Check that all locking cams engage cleanly with no handle resistance. A stiff handle means dry hardware or sash misalignment.

Step 2 of 2: The Orloffs Protocol

The Orloffs Protocol

Pro Tools

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

Follow these steps in order. Each one builds on the last. This is the same sequence I use on every Oknotherm 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 Oknotherm 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 Oknotherm 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 Oknotherm 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.

Pro Tips

• ★ On colour foil PVC windows, always test any new cleaning product on the inside face in an inconspicuous corner before using it on the exterior - solvent damage shows as a dull patch or foil lift that starts at the edges.
• ★ Road salt on lower window frames does not dissolve in cleaning solution the same way that general dirt does - pre-rinsing with plain water is the only way to properly clear it before the main clean.
• ★ PVC drainage slots in tilt-and-turn sashes often have a small plastic grill insert. These grills can be removed for cleaning - remove them, brush clean, and refit rather than trying to clear the slot around them.
• ★ A PVC frame that has turned grey or beige over time can often be significantly improved with a specialist PVC restorer product. Test on an inconspicuous area first - restorers work well on standard PVC but can lift foil on laminated profiles.
• ★ Czech and central European winters leave a combination of road salt, grit, and anti-freeze product deposits on ground-floor windows. Treat this combination carefully - anti-freeze residue is a mild solvent that can affect foil laminates.
• ★ Handle resistance on a mid-range PVC window increases much faster when the corner transfer piece is dry than when it is regularly oiled. Make the corner piece the first lubrication point on every annual service.
• ★ EPDM rubber seals on PVC windows dry out and crack in 10 to 15 years. A seal that has cracked along its length is no longer weathering the window and needs replacement - no amount of seal conditioner repairs a cracked seal.

What NOT To Do

Bundle Kits and Tool Recommendations

Cleaning Frequency

Glass: 2x per year minimum (Urban and road-facing locations may benefit from quarterly cleaning in winter months when salt deposits are heaviest.). Frames: 2x per year (Same visit as glass. Colour foil frames benefit from more frequent light cleaning to prevent deposit buildup that requires harder cleaning.). Drainage slots: Every clean (The single most important maintenance task on Czech PVC tilt-and-turn windows. Do not skip.). Hardware lubrication: Once per year (Annual service prevents stiff handles and premature mechanism wear.)

Frequently Asked Questions

Field Notes

“Czech mid-range PVC windows represent good value when correctly maintained. The material quality is sufficient for a 25-year window life with regular cleaning and annual hardware service. The foil laminate issue on colour Czech windows is the most common cause of early cosmetic failure. A solvent-contaminated foil edge on a dark-colour window is immediately visible and is not covered by manufacturer warranty if cleaning products were involved. Road salt season in central European cities runs from November through March. Ground-floor windows in this zone need a different pre-clean protocol during these months than at other times of year.”

Justin Orloff