What Grit Sandpaper for Walls? Easy Picks
You only notice sanding when it goes wrong – swirl marks that show through fresh paint, edges cut back to bare plaster, or filler patches that still look like islands. Picking the right grit for walls is what stops that happening. It is less about “the best grit” and more about what you are sanding: paint, filler, plaster, or wallpaper paste, and how rough it is right now.
What grit sandpaper for walls depends on
Grit numbers work backwards to what most people expect. A low number is coarse and cuts fast. A high number is fine and smooths rather than reshapes. On walls, you usually want to remove as little as possible while still getting a flat surface that paint can sit on.
There are three questions that decide your grit choice.
First, are you shaping something (like proud filler) or just keying a surface for paint? Shaping needs a lower grit. Keying is a light scuff so new paint sticks, and that wants a higher grit.
Second, how fragile is the surface? Fresh plaster and soft filler can tear or gouge if you start too coarse. Old gloss paint can clog paper if you go too fine too soon.
Third, what finish are you aiming for? Matt emulsion is forgiving, but silk, satin and any strong side lighting will highlight scratches. If you are painting with a sheen, you need a finer final sand.
The quick answer: the grits most people actually use
For most UK DIY wall jobs, you will keep coming back to three bands.
80-100 grit: for heavy removal only
Use 80 or 100 grit when you genuinely need to flatten something quickly. Think thick filler that is standing proud, drips and nibs in old paint, or a lumpy edge where plaster was repaired. It is effective, but it can also leave visible scratches if you stop there.
On old plaster, 80 grit can be too aggressive unless you have a very uneven patch to level. If you do start at 80, plan to step up afterwards rather than painting straight over it.
120-150 grit: the all-rounder for walls
If you are asking “what grit sandpaper for walls” because you are decorating a room and want a sensible default, 120 to 150 grit is usually it.
This range will smooth most filler, feather the edges of a repair into surrounding paint, and key existing emulsion without shredding it. It is also a good middle step if you began with 80-100 and need to remove the scratch pattern.
180-240 grit: for finishing and between coats
Use 180 to 240 grit when the wall is already in decent shape and you are chasing that final smoothness. It is ideal for a light sand before painting, for de-nibbing between coats (once the paint is fully dry), and for minimising visible scratches under satin or silk finishes.
If you are working under a bright lamp or you have lots of natural light hitting the wall, finishing at 180 or 240 can make the difference between “fine” and “professionally tidy”.
Matching grit to the job (common scenarios)
Walls rarely present as one neat category. Here is how to choose grit based on what you are standing in front of.
Previously painted emulsion walls
If the paint is sound and you are just refreshing the colour, you usually do not need to strip anything back. You want a key.
Start with 150 grit for a quick scuff sand, then dust off properly. If the wall already feels smooth and you only have the odd nib, go straight to 180 or 240 and keep it light. You are not trying to remove the colour, just to take away shine and knock down roughness.
Gloss or satin paint on walls (or shiny patches)
Hard, glossy surfaces can be awkward because they are designed to resist wear. A slightly coarser key helps.
Use 120 grit to break the shine, then step up to 150 or 180 for a more even scratch pattern. If you sand gloss with very fine paper only, you can spend ages and still not properly key it.
Filler patches and repaired holes
Filler is where most sanding marks come from. The trick is to shape with a grit that cuts, then finish with a grit that hides.
If the filler is proud, begin at 120. If it is very proud or you have lots to knock back, start at 80 or 100 but keep the sanding block flat so you do not create a dip. Once the patch is level, switch to 150, then finish at 180 or 240 to blend the edges into the surrounding wall.
A common mistake is using a coarse grit right up to the feathered edge. That is how you end up with a visible halo under paint.
Bare plaster (new or newly skimmed)
Fresh plaster does not want heavy sanding. Often it only needs a light pass to remove the odd trowel mark, and plenty of dusting.
Start at 180 grit and be gentle. If there are raised lines you can feel, drop to 150 for those spots, then return to 180. Avoid 80-100 on fresh plaster unless you are dealing with a specific high ridge and you know you can keep the surface flat.
Removing wallpaper paste residue or rough backing
If you are sanding paste residue, you may clog paper quickly. It can help to wash and scrape first, then sand.
Once the wall is dry, use 120 or 150 to knock back roughness, then finish with 180. If you go too fine too soon, you can just polish the residue rather than level it.
Paper type matters as much as grit
Not all sandpaper behaves the same on a wall.
Aluminium oxide paper is the usual choice for general sanding and is fine for most decorating. For very dusty jobs like plaster and filler, look for sheets labelled for plaster or drywall, or a mesh abrasive. Mesh tends to resist clogging and keeps cutting for longer, especially if you are sanding larger areas.
Whatever you choose, put it on a sanding block or a pole sander. Fingers alone make grooves. A flat block spreads pressure and helps you level the surface rather than just scratching it.
How to sand walls without making a mess of them
Walls are large, and small errors repeat fast. The goal is a uniformly dull, smooth surface.
Work in light, even passes and check your progress with your hand. Your fingertips will find ridges your eyes miss. If you have a work light, hold it at a shallow angle across the wall. That raking light shows proud filler and sanding swirls immediately.
Do not press hard. Let the abrasive do the work. Pressing creates low spots in filler and can burnish paint, which is the opposite of keying.
Keep your grit changes honest. If you start coarse, you need enough time on the next grit to remove the previous scratch pattern. A quick tickle with 180 after 80 grit will not erase the deeper marks.
Dust control that actually helps
Sanding dust is not just annoying – it ruins paint adhesion if it stays on the wall.
Vacuum the wall (soft brush head), then wipe down. A slightly damp microfibre cloth works well, but do not soak the surface, especially on fresh filler. Let everything dry before you paint.
If you are doing more than a couple of patches, consider a dust sheet, masking along skirtings, and a decent mask. Plaster dust gets everywhere and it is far easier to prevent than to clean.
A simple grit plan for a typical room refresh
Most people are repainting a lived-in room with a few nail holes, a couple of scuffs, and maybe a repaired crack.
Start by filling and letting it cure fully. Then sand filler with 120-150 until level, finish those patches with 180-240, and finally give the rest of the walls a quick, light key with 150 or 180. That combination is fast, forgiving, and it keeps scratch marks to a minimum.
If you are only doing touch-ups and the walls are already smooth, 180 is often enough for everything.
When to stop sanding (and start painting)
Stop when the wall feels consistent. Run your hand across repair edges – you should not feel a step. Look from the side with a light – you should not see sharp ridges or obvious scratch arcs.
Do not chase perfection by over-sanding. It is easy to thin paint at corners and edges or create a hollow in filler. If you can feel a dip, it often needs a skim of filler rather than more sanding.
If you are stocking up for a decorating job and want to keep it simple, a couple of packs covering 120/150 and 180/240 will handle most wall situations, plus you will use the leftovers for the next room. Homepride Online customers often build a sensible basket like that alongside filler, masking tape and dust sheets, so you are not stopping mid-job waiting for supplies.
The best sanding choice is the one that gets you to a flat wall with the least aggression – start as fine as you can, go coarser only when you must, and your paint will do the rest.