How can I get floor paint to stick better on our outside stairs?

Question

We have stairs leading down to our flat which are outside and we have painted them a few times, but the paint doesn't seem to stick very well, and always starts peeling off.

It mainly peels in the same places, which is where water drips on the stairs from the balcony above when it rains. We can't stop this dripping and so I want to know what my best options are for painting that will minimise the chances of it peeling off.

Previously the old coats of paint were not properly removed (the work was always done by people organised by the managing agents, we will be doing it ourselves this time) and so I'm going to use a drill scrubber to try and remove the paint first.

But is there anything else I can do?

Will adding PVA to the paint make it more likely to stick?

Is there some paint that is better to use?

Answer 1

Peeling paint is caused by poor adhesion to the underlying surface. For stone and concrete a professional would recommend grit/sand blasting. This ensures removal of all surface contaminants which could affect adhesion.

If you insist on doing it yourself: remove all existing paint, wire brush entire surface, wash surface with mild acid solution (we use pool acid called Muriatic Acid, it is actually weak hydrochloric), rinse clean and dry. Use a high quality outdoor concrete coating and apply as directed by the manufacturer's instructions using high quality applicators (brushes & rollers). Some of the epoxy coatings do not require a primer. Do not use an additive unless directed to by the manufacturer.

It has been my experience that you will find the best coatings (and advice) at a paint shop or commercial/industrial supply house, rather than at a "big box" store.