Hi,
I want to paint my concrete retaining wall sleepers, what do I need to do first, should they be painted with a brush, roller or spray gun & how long should it last?
Cheers
Barry
Hello @bschebella
There is an important factor to take into consideration before you paint either timber or concrete sleepers. Was the back of the sleeper sealed or painted with a waterproofing membrane before it was covered with soil? An indication that no sealer was applied is that the front of the sleeper often has heavy condensation and has moss or mould on the surface, and despite numerous cleaning efforts the moss and mould always return.
When paint is applied to the surface of the unsealed sleeper water coming from the other side will pass through the sleeper in the form of heavy moisture and will literally push the paint off the surface of the sleeper. Even with multiple coats the paint will bubble, peel and come off. This water pressure coming from the other side of the sleeper is known as hydrostatic pressure.
In order to paint the sleeper without the paint coming off, it will be necessary to remove the soil from the back of the sleeper. The back side of the sleeper will then need to be painted with a moisture sealer such as bitumen paint. Once the paint cures the soil can then be put back. The front of the sleeper can then be power washed and once dry can be painted with an exterior paint.
But for now, all I can suggest is to clean the surface of the sleeper and leave it in its natural state.
If you need further assistance, please let us know.
Eric
