If you need advice about a painting or decorating problem not covered elsewhere on the site please leave a comment below.
Grace – Hi, we have a long standing exterior masonry wall which is the dividing wall between our driveway and our neighbours. Over the past couple of years after painting with masonry paint the paint has started to peel and flake off and looks terrible. The last time it happened I contacted the manufacturer of the paint and they said that the photographs showed that it was the paint underneath the most recent coats that was the problem as it was pulling away from the wall taking the newer coats with it. They also said there was some evidence of mould and I wondered before we paint the wall again what do you recommend we do to provide a good key and base for the new paint? Do we need to use a stabilising solution or anti fungal? Your help and advice would be greatly appreciated. READ MORE…
Not much I can add other than what you’ve already been advised, which sounds fair. The paint is only going to be as good as the surface you’re applying it to. So any loose material and mould needs to be removed before you do anything.
You don’t give any information about this wall or its construction/design, so impossible to give any further advice on this.
As for applying a stabiliser, there is ample information already here that you haven’t read so I suggest you start there.
Hazel – Please can you recommend a dirt and moss resistant masonry paint. READ MORE…
There are a few specialist manufacturers of exterior paint that claim to me mould and dirt resistant but I am not not going to recommend any of them since a lot depends on the type of surface, its current condition and location as to whether these paints have any chance of providing better protection than a regular masonry paint.
There is also no factual information that I am aware of that proves any of these paints actually work, other than their own publicity.
Hello, I’m trying to repaint an old granite slab carvings which is used outdoors. What are the most durable options that I have? I heard about some acrylic based paints that is claimed to last 10 years or polyurethanes, but I come across waterglass based paints that are supposedly last longer. Are these the best options that I have or are there better options? READ MORE…
The paints you mention will perform well as a surface finish but your biggest problem is obtaining a successful bond with the granite surface to begin with.
First you’ll need to remove any shine from the surface with fine wire wool and thoroughly degrease the surface before painting.
A surface preparation treatment such as Owatrol ESP will be your ideal first step. This will help any subsequent coats to adhere to the surface without the risk of peeling or scratching off.
Also bear in mind that most products you use as a top coat will have a curing time that goes far beyond surface drying times (sometimes a few weeks) so you’ll need to avoid the risk of damage during this time until the paint has fully hardened.
The exception to this rule is with with some industrial quality 2-part products which will cure more or less straight away.
Ahmed – Hi, I am having a problem with damp in my upstairs bedroom wall, directly underneath the window. I just had my windows replaced 1 year ago, there was no damp in this area prior to that. There is a lot of black mould gathering now, and paint flaking off. Could this be solely down to the windows not being fitted properly, or could there be another underlining problem? The damp-proof company said there’s no need to damp proof higher up on the rest of the wall, as he said his damp meter was showing that part as being okay. How reliable is this information? READ MORE…
Hard to say without seeing the problem but such problems are usually caused by either condensation or trapped moisture.
It could be that your old windows were a bit drafty but were also providing adequate ventilation to prevent the build-up of condensation in this area.
Or, they have used a hard, non-breathable damp-proofing plaster and/or paint finish which is holding in moisture behind the surface. This could cause a cold-spot which is allowing moisture in the air to condense on the surface – hence the black mould. This would also explain why paint is flaking-off because the trapped moisture is forcing its way out.
As I say, pure guesswork on my part, but you will need to get to the root of the problem before attempting to redecorate.