Smoothing a Wall: Filler, Lining Paper or Plastering?

Smoothing a wall: filler or a coat of plaster after all

A few holes from wall plugs or a small unevenness, you can fill yourself, and that’s done in an afternoon. A wall that feels bumpy everywhere, is built up with layers of old paint, or was never properly flat to begin with, only gets truly smooth with a new coat of plaster over the whole wall. Filler works spot by spot, plastering works over the whole surface.

The difference is in the scale of the problem. If you see two or three spots that stand out, touching them up is the quickest route and you don’t need a plasterer. If you feel the unevenness across the whole wall as soon as light hits it at an angle, filler work stays just as bumpy as the surface underneath. Levelling a wall with filler alone doesn’t work then: filler fills a hole, it doesn’t create a flat surface.

Lining paper or plastering: the difference

Lining paper isn’t a way to smooth a wall, it’s a way to hide small, non-moving cracks. You stick a thin glass-fibre fleece over the wall and put a coat of paint over it, so hairline cracks don’t come back through in the finish. The wall itself doesn’t get any flatter from that. Bumps and unevenness just stay where they are, you’ll see them again through the fleece.

Plastering takes a different approach. I apply a layer of plaster over the whole wall that actually gets rid of the unevenness, not just hides what’s underneath. If you want the wall to actually feel flat, and look smooth in raking light too, lining paper isn’t enough. Then you need plastering.

Smoothing old layers of paint

A wall with several layers of old paint often already feels rough before you put anything new on it. Each layer sits over the previous one, and after a few coats you see brush strokes and unevenness more and more clearly. Sanding helps a little, but with thick or uneven layers of paint, that alone won’t get the wall properly flat again.

In that case I plaster straight over the old paint, after a primer coat that makes sure the new plaster bonds properly. That way you don’t have to strip off all the old paint first, which usually creates more mess and work than the plaster coat itself.

Here’s a review left in Dutch on Werkspot:

“Stucwerk muur in de woonkamer: Super strak en mooi. Heel blij mee! Netjes gewerkt en glad achtergelaten. En heel vriendelijk! Aanrader.” Source: Werkspot user from Streefkerk (Werkspot review)

Smoothing old plasterwork

An old wall in base coat, so a rough underlayer without a proper finishing layer, was never meant to stay like that. That surface is uneven and porous, and a coat of paint or wallpaper won’t make it smooth. I first work out the biggest unevenness in the base layer, then apply the finishing layer that gives the wall its crisp look.

The same applies to a more complex renovation, even when the wall itself is already unusual. For Jan in Goirle, it was a whole sloped wall that had stood uneven for years. Here’s his review, left in Dutch on Werkspot:

“Een echte vakman! Osman werkt zeer netjes, is stipt op tijd en komt zijn afspraken altijd na. De communicatie verliep uitstekend, ondanks dat hij iets minder Nederlands spreekt – dit vormde absoluut geen enkele belemmering. Onze stucklus was behoorlijk complex (waaronder een volledige schuine wand van 4,2 meter hoog en 11 meter lang), maar het resultaat is werkelijk prachtig en tot in de kleinste details strak afgewerkt. Bovendien liet hij alles na afloop keurig opgeruimd achter. Wij zijn ontzettend blij met het eindresultaat en zouden Osman zonder twijfel opnieuw inhuren. Een absolute aanrader!” Source: Jan, Goirle (Werkspot review)

Smoothing holes and grooves

A hole from a drilled wall plug or a groove from old pipework isn’t something you smooth with filler alone, especially not when it involves several spots next to each other. Fill a hole like that too thinly, and you’ll still see the repair later as a slight dip in the wall. I build up the depth in layers and finish the last one flush with the rest of the wall, so there’s nothing left to see afterwards.

If there are loose bits of plaster already coming away around the hole, I remove those first before starting again. Otherwise the repair ends up sitting on a weak spot. Have a look at plaster repair if the wall has more cracks or holes than you want to touch up yourself.

Here’s what one client wrote, in Dutch, on Werkspot:

“Super lieve man. Super eerlijk en duidelijk. Echt vakwerk. Eerlijke prijs. Komt afspraken na. Als je geen gedoe of hoofdpijn wilt, moet je Osman hebben.” Source: Gurtej, Klaaswaal (Werkspot review)

Smoothing new gypsum blocks

New gypsum blocks are flatter than an old wall, but they’re not smooth. The joints between the blocks and small unevenness in the surface stay visible until a finishing layer goes over them. Filler on the joints alone often leaves a slightly raised line visible as soon as light hits it at an angle.

I plaster a new gypsum-block wall smooth in one coat, joints included, so the whole wall looks like a single flat surface. For Thymen in Vught, it was exactly that kind of job, a cupboard built from gypsum blocks. Here’s his review, left in Dutch on Werkspot:

“Zeer snelle reactie, zelfde dag werkzaamheden nog uitgevoerd. Netjes gewerkt en met heel correct en prettig in communicatie. Topwerk afgeleverd” Source: Thymen Houwen, Vught (Werkspot review)

Filler, lining paper or plastering: the overview

Put the three options side by side, and you see where the difference lies: not in how much effort it takes, but in what it actually delivers.

Smoothing a wall for wallpaper or for paint

What “smooth enough” means depends on what’s going onto the wall afterwards. If you’re painting, a wall that’s smooth and ready for paint is enough: smooth enough that the texture no longer shows through a coat of paint. If you’re wallpapering, the wall needs to be ready for wallpaper, because under thin wallpaper, every unevenness stands out even more.

So levelling a wall for painting doesn’t automatically mean the same coat as for wallpaper, to me. I always ask beforehand what’s going onto the wall after me, so I apply the final coat with the right finish. Still not sure yourself? I explain the difference between ready-for-paint and ready-for-wallpaper further under wall plastering. Going straight on to painting new plaster? Also have a look at priming plaster for the step that comes after.

When it’s better to call in a plasterer

If you want a wall that’s completely crisp even under raking light, that’s the point to have a plasterer come round instead of carrying on filling it yourself. Filler and lining paper solve a problem in one spot, a plasterer plasters the whole wall in one coat, and that’s the difference you’ll see later, as soon as the afternoon sun comes in at an angle.

Send a few photos of the wall, and I’ll quickly see whether filler is enough or whether it needs a new coat of plaster.