Posts Tagged ‘flaking’

Wallpaper Paste Residue = Crackled Ceiling Paint

July 13, 2022

You’re looking at the junction between a wallpaper border at the top of a wall and the ceiling. You can see crackled and flaking paint on the ceiling.

This was almost surely caused by the previous wallpaper installer getting paste on the ceiling (which is typical and normal) but failing to wipe it off completely.

The paste is clear and difficult to see. Even when you do a diligent job, it’s easy to leave some residue behind.

The problem is that wallpaper paste attacks water-based paint, and will cause it to do what you see above … crackle, flake, chip off. This can happen if the paint was in place before the wallpaper paste got on it, or if there was paste residue and fresh paint was applied on top of it.

In fact, the decorative paint finish called “crackle finish” is accomplished by applying hide glue onto a surface and then coating it with latex paint.

The crackly paint on the ceiling is unattractive, and impedes adhesion. It takes a lot of scraping and sealing and skimming the wall to rectify this.

A way to avoid this is to astutely wipe off all paste residue. Better yet, what I do is to use special plastic tape at the top of my wallpaper strips, so that no paste gets onto the ceiling in the first place. Do a Search here to see previous posts describing that technique.

You can also use a stain blocker like KILZ Original oil-based primer, or BIN shellac-based primer, to seal off the area before painting. There are water-borne primers that claim to seal such problem areas – but I prefer to stick with oil or shellac.

Paint Problem

May 30, 2020


Hard to see, but the paint on this wall is crackling. This is most likely because there are unstable and incompatible layers of paint underneath.

In an old house like this (1940’s), there will have been many treatments to the walls over the years. Original oil-based paint, covered by latex paint, gloss paint, dust, more colors and layers of paint. And virtually never does the workman prep the walls properly.

Latex doesn’t like to stick to oil, and most paints don’t like to stick to gloss, plus other factors. So what happens is that all these disparate layers rebel, and sometimes you end up with flaking or peeling.

If wallpaper is applied on top of these unstable walls, when it dries and pulls taught and puts tension on the wall surface, there is the potential for these layers to give way, and you can end up with a curled seam, under which are layers of delaminated wall.