Best Way to Clean Windows Inside for a Professional Finish

There’s a particular frustration that comes with trying to find the best way to clean your windows inside. You try endless sprays and waste more paper towels than you’d like to admit, only to find yourself staring at a window pane covered in streaks, smears, and what appears to be more marks than you started with.

Sound familiar? Read on for the exact method professional window cleaners (like our team at Stuart’s Cleaning Services) use for getting that spotless, streak-free finish on interior windows.

The Tools That Make the Difference

Before you start cleaning, it’s important to have the right supplies. Here are the four essentials you’ll need to have on hand.

Microfibre Cloth Designed for Glass

In our opinion, the single most important tool for interior window cleaning is a good quality microfibre cloth. Not all microfibre cloths are equal though, and the key is to use one specifically designed for glass, with a tight weave that picks up residue rather than redistributing it across the surface. You can find these in most supermarkets, and they tend to be clearly labelled for glass or polishing use.

It’s important to note that a standard household microfibre cloth used for general cleaning will often leave lint and fibres on the glass, which is exactly what you’re trying to avoid. So it’s worth making an effort to buy the right cloth.

Rubber-Bladed Squeegee

The second tool worth investing in is a small rubber-bladed squeegee. This is the tool professional window cleaners use on interior glass, and it’s the most reliable way to remove cleaning solution from the pane without leaving streaks. A squeegee with a blade width of around 30 to 35 centimetres works well for standard window sizes.

The rubber blade also needs to be clean and in good condition, as a blade with nicks or dried residue on it will leave marks on the glass rather than removing them.

Washing-Up Liquid and Water

For the cleaning solution itself, one of the most effective options for interior windows is washing-up liquid diluted in warm water. And contrary to what many people think, you actually want to use a little more than you’d expect.

The solution needs enough body to cling to the glass properly rather than running straight down the pane before you’ve had a chance to work with it. A good amount of washing-up liquid in a bucket of warm water will help loosen grease, fingerprints, and everyday grime more effectively, while giving you enough time to properly squeegee the glass before the solution dries.

Regular tap water works perfectly well for interior window cleaning and is what we use ourselves for the majority of jobs. Warm water combined with washing-up liquid is usually more than enough to achieve a clear, streak-free finish when used with the right technique and tools.

The Best Way to Clean Windows Inside: 4 Key Steps

The secret to the best way to clean windows inside comes down to working in the right order. Here’s what that process looks like from start to finish.

Step 1: Clean the Frames and Sills First

Frames and sills harbour dust, grime, and spider webs that will transfer directly onto the glass the moment you start cleaning it. That’s why it’s important to use a dry cloth to wipe down the frame and sill first, then follow with a slightly damp cloth if there’s visible grime.

Step 2: Apply the Cleaning Solution

Once the frame is clean and fully dry, apply your cleaning solution to the glass using a damp microfibre cloth or a soft sponge. Work in a consistent pattern, either horizontal strokes or a circular motion, making sure to cover the entire pane.

The goal at this stage is to loosen and lift the dirt from the glass, not to dry it. Don’t worry about streaks at this point because you’re not finished yet.

Step 3: Remove the Solution with a Squeegee

The next step is where most DIY attempts go wrong. Many people try to dry the glass with the same cloth they used to apply the solution, which simply moves the residue around rather than removing it.

Instead, use your squeegee to pull the cleaning solution off the glass in overlapping strokes, wiping the blade clean with a dry cloth between each stroke. Start at the top of the pane and work downward. This is the technique that produces the streak-free finish you’re aiming for.

Step 4: Finish with a Dry Buff

Finally, use a clean, dry microfibre glass cloth to buff any remaining marks from the edges and corners that the squeegee couldn’t reach. Hold the cloth flat against the glass and use a circular motion rather than wiping back and forth, which tends to redistribute residue rather than removing it.

This final step is what takes the glass from clean to properly clear.

The Most Common Mistakes and How to Avoid Them

Even with the right tools and method, a few small mistakes can undo your efforts and leave you with that annoyingly streaky finish. Here are four common mistakes to watch for and how to avoid them.

Cleaning in Direct Sunlight

This is actually one of the most consistent causes of streaky interior windows, but not many people other than the professionals know about it. When sunlight hits the glass while you’re cleaning, it dries the cleaning solution faster than you can remove it, leaving behind residue before you’ve had a chance to squeegee it off.

The best way to clean windows inside is on an overcast day, or in the morning or evening when direct sunlight isn’t hitting the glass. If you can only clean during the day, start with the windows that are in shade and work your way toward those in direct light.

Using Too Much Cleaning Product

Excess cleaning solution is one of the most common causes of smearing on interior glass. The solution leaves a film on the glass as it dries, and the more solution you use, the thicker that film will be.

You’ll want enough washing-up liquid in the water for the solution to cling to the glass properly rather than running straight off the surface. If you’re using a spray bottle, two or three sprays per pane is sufficient. Any more than that and you’ll be fighting the residue for the rest of the clean.

Using the Wrong Cloth

Paper towels, newspaper (an old-school recommendation that has largely been superseded, and standard cotton cloths all leave fibres or residue on glass.

That’s why it’s important to use a dedicated glass microfibre cloth, as it’s designed to lift residue off the surface rather than spread it around. It’s also a good idea to keep your glass cloths separate from your general cleaning cloths so you don’t transfer dust, grease, or cleaning product onto the glass.

Make sure to wash your glass cloths without fabric softener too, as this can leave a residue on the fibres that transfers directly onto the glass.

When to Call a Professional for Interior Window Cleaning in South West London

Even though most interior windows can be cleaned effectively yourself, there are still some situations that call for bringing in the professionals.

We recommend calling a local window cleaner if:

• Your windows haven’t been cleaned in a long time and have built up a heavy film of residue that’s difficult to remove.
• You want a proper reset clean before maintaining them yourself going forward.
• Your property has large panes or floor-to-ceiling glazing that are harder to clean evenly.
• You have windows in awkward or hard-to-reach areas, such as above staircases.
• Safety is a concern, and you’d rather avoid working at height or stretching across difficult angles.

At Stuart’s Cleaning Services, we offer interior and exterior window cleaning across Richmond, Twickenham, and the wider South West London area.

So if you’re based in South West London and your windows need a proper reset, or maybe you’d just rather hand the whole thing over to someone who does this every day, we’d be happy to help.

Get your free instant quote today, and let’s get your windows looking clear again.