Deventer Profielen — 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 mild soap. Keep solution away from the rubber compression seal perimeter - solution that sits against the seal during the wash phase degrades the seal surface over repeated applications.
• ✓Squeegee solution away from the seal line where possible. Direct the squeegee bead toward the drainage slot, not toward the seal.
• ✓After squeegeeing, wipe the glass edge near the glazing gasket with a barely damp cloth. Do not push moisture into the junction between the glass edge and the gasket.
• ✓No solvent-based glass cleaners. No ammonia-based cleaners. Both attack EPDM and TPE seal materials.

Frames

• ✓Wipe frame faces with damp cloth and pH-neutral cleaner. Rinse thoroughly - residue left on the frame near the seal groove attracts grime that sits against the seal between cleans.
• ✓On the seal itself, wipe gently with a barely damp cloth if the seal surface is visibly dirty. Do not scrub. Do not apply cleaning product directly to the seal.
• ✓Check the seal groove at the frame perimeter - particularly at the corners where the seal is most likely to have lifted or pulled away. A seal that is not seated fully in the groove needs to be pressed back in - do this by hand, not with a tool.
• ✓No bleach, chlorine, or solvent products on or near any seal. The most common source of seal damage on PVC installations is bleach used on the frame surface dripping onto the adjacent compression seal.

Hardware

• ✓Hardware maintenance is separate from seal maintenance but related - stiff or poorly adjusted hardware causes the sash to compress unevenly against the perimeter seal, loading some seal sections more than others. Keep hardware lubricated to ensure even sash compression.
• ✓On doors with Deventer automatic drop seals, clean the threshold contact surface - the floor or threshold bar that the drop seal compresses against - at every visit. Grit on the contact surface wears the seal lip faster than normal operation.
• ✓Check that the drop seal on entrance doors extends and retracts smoothly. Grit or debris in the seal mechanism prevents full extension and leaves a gap at the door bottom when closed.

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 Deventer Profielen 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 Deventer Profielen 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 Deventer Profielen 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 Deventer Profielen 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

• ★ The most useful tool for EPDM seal maintenance is a dedicated seal conditioner applied once per year after cleaning. It restores flexibility and significantly extends service life beyond what cleaning alone achieves.
• ★ Compression seals that are flat at the corners but still functional in the straight sections have usually been over-compressed by a sash that is adjusted too tight - flag this as a hardware adjustment issue, not a seal replacement issue.
• ★ On aluminium windows with exposed EPDM seals on the sash front face, the seal is the most visible maintenance indicator on the whole window. A grey, chalky EPDM surface is a sign of UV degradation or solvent exposure - not dirty glass.
• ★ Deventer drop seals on entrance doors are adjustable - the descent depth can be set to match floor level. If a drop seal is leaving a gap at the door bottom, it may need adjustment rather than replacement.
• ★ On PVC installations where the compression seal is recessed in the frame groove, it is easy to miss during cleaning. Run a finger along the seal groove after the frame wipe to feel for grit or residue that was not removed by the cloth.
• ★ In cold weather, EPDM seals become stiffer and less compressible - windows that seemed to close properly in summer may admit a draught in winter. This is a hardware adjustment issue, not a seal failure.
• ★ Keep a note of seal condition at each visit. A seal that changes condition significantly between two visits - faster than normal weathering would explain - indicates that something is attacking it between cleans.

What NOT To Do

Bundle Kits and Tool Recommendations

Cleaning Frequency

Glass: 2x per year minimum (Spring and autumn. The seal inspection at each glass clean is as important as the glass cleaning itself.). Seal inspection: Every clean (Visual check of all compression seals, glazing gaskets, and door seals at every visit.). Seal conditioning: Once per year (EPDM-compatible conditioner applied after the annual autumn clean.). Drop seal adjustment: As needed (Check drop seal descent depth annually or when a draught is reported at the door bottom.)

Frequently Asked Questions

Field Notes

“The most useful observation a professional cleaner can make on a Deventer-sealed window is seal condition at the corners - corners are where seals lift first, and lifted corner seals are invisible to the owner but obvious to a trained eye. On Dutch and Belgian residential windows, Deventer seals are ubiquitous - if you work in the Benelux market, you are working with Deventer seals on most of your jobs whether you know it or not. Automatic drop seal maintenance on premium entrance doors is a professional service almost never included in a standard cleaning contract - it takes five minutes and saves seal replacement costs.”

Justin Orloff