Repair Hairline Cracks



Repairing Hairline Cracks

A hairline crack is a crack in a wall that is as thick as a hair, a very small, shallow crack. It is only on the surface of the plaster and can be caused by many factors, house settling, incorrect plaster mix or walls that have been painted while still wet to name a few. Let’s have a look at the way to tackle the repair.

Because these cracks are so tiny we’re going to cover them with a thick textured paint. This is a high build pure acrylic which is a lot thicker than your normal paint. Apply this as a crack bridger, but paint it over the entire affected wall. If you paint it exclusively over the cracks, a difference in sheen, texture and in the height of the paint will be noticeable once the topcoats have been applied.

It can be applied with a roller with a 6mm nap and a cut brush for the edging. As always, use a drop cloth to prevent paint splatter from damaging the surface below. Depending on weather conditions, the paint should be left to dry for two hours before being over-coated.

As this paint is an acrylic PVA, the wall doesn’t need an undercoat.

Once it is dry, apply two topcoats which match the rest of your walls. One topcoat may look good, but it will not provide the protection and colour match over a period of years that you’ll get with two coats.

Hairline cracks can be quite disturbing to the homeowner when seeing them for the first time. Take a scraper and enlarge one. If it’s only visible on the surface don’t worry, it’s an easy fix. It’s the cracks that run through the plaster to the wall that can give you nightmares.


Hairline cracks