For a streak-free result, use a cleaning method approved for your glazing, keep cloths and tools clean, remove the cleaning solution evenly and finish the edges. Dirt on the tools or residue left behind can undermine an otherwise careful clean.
Check the glass and frame requirements
Before selecting a product, check whether the glazing has a special coating, film or manufacturer-specific care instructions.
Frames, seals and fittings may need different care from the glass. Do not assume that a product suitable for one material is appropriate for the whole window.
Andersen’s care guidance recommends suitable cleaning solutions and removal with a squeegee or clean lint-free cloth, while discouraging harsh abrasive cleaners.
Reference: Andersen window care guidance.
Choose manageable conditions
Avoid cleaning hot glass in direct sunlight where possible. Working on cooler glass gives you more control over the cleaning and drying process.
Prepare separate clean cloths for glass and dirtier frame areas. A cloth used on a dusty sill should not become your finishing cloth.
Reference: Andersen glass-care instructions.
Work through each window methodically
- Inspect the window for damage and identify any special care requirements.
- Remove loose dirt from accessible frames using a suitable method.
- Apply the approved glass-cleaning solution as directed.
- Work across a manageable area with a clean tool.
- Remove the solution evenly using a suitable squeegee or lint-free cloth.
- Finish the accessible edges and inspect from another angle.
Avoid letting dirty water collect on finishes that may be sensitive to moisture.
Why streaks keep appearing
Check the simple things before using a stronger product:
- Is the finishing cloth already damp or dirty?
- Is the squeegee blade worn or carrying debris?
- Are you using more product than the instructions require?
- Is the solution drying before you remove it?
- Is water running back from the frame onto finished glass?
Changing the tool or technique may be more useful than repeating the same process.
Cleaning outside and upstairs windows
Only work where you have safe access. Do not lean out of upstairs windows or improvise a platform to reach difficult glass.
For high or awkward windows, arrange a service able to assess suitable access and equipment.
Image brief: the same genuine job, with matching framing and similar lighting.
What cleaning may not resolve
Marks on the surface differ from scratches, damaged coatings or misting between panes.
If cloudiness appears inside a sealed glazing unit, further surface cleaning may not address it. Ask a glazing professional to assess the issue.
For business premises, visit our commercial window cleaning page.
Common questions
Can I use the same method on every window?
No. Coatings, films, frame materials and manufacturer instructions can change what is suitable.
Should frames be included in a window-cleaning booking?
Confirm whether the quotation covers glass, frames, sills and other details rather than assuming.