Pliolite is often mentioned by people requesting advice about exterior masonry paint and, it seems, there is some confusion about what it actually is.
‘Pliolite’ is a form of synthetic rubber resin formulated for use in paints. It dries fairly quickly and is highly resistant to damp and water damage within just a few minutes of application.
This makes it ideal for use if you’re painting exterior masonry in damp climates or where there is a likelihood of rainfall.
In a domestic setting, however, there really isn’t any need to be doing this because you can simply put off the painting until there is better weather.
In the commercial world though, you may not have this luxury and, sometimes it is necessary to get the job done regardless. This is where Pliolite-based paint is useful.
In terms of performance or suitability though, there is no reason to use Pliolite paint and a regular water-based masonry paint will do the job just fine.
The confusion comes from painters and builders who are ill-informed and recommend these paints because they are expensive and sound technically impressive.
They have the idea, somehow, that you can make walls ‘waterproof’. In reality, it isn’t going to happen…water will get into the walls through small hairline cracks and become trapped..causing yet further problems down the line.
This problem is mitigated, to an extent, with ordinary masonry paint because it is breathable and will allow normal level of moisture to evaporate away.
Here is a sample of the questions raised…
Water Based or Pliolite?
My 1860’s house has solid brick walls that have been covered with a sand / cement render followed by a tyrolean finish. I want to paint them with an exterior emulsion to reduce dampness when the walls are subject to heavy rain. They also have some fine cracks but the render seems essentially sound.
One painter I have spoken too would recommend a water based exterior emulsion, but another favours a solvent based pliolite paint. Would the latter be as breathable? I can’t find much info on breathability of pliolite paint.
What would you recommend?
Pliolite is a synthetic rubber resin and not naturally moisture permeable. It would, therefore, be a poor choice in this instance.
The fine cracks you mention should also be remedied in order to prevent the ingress of moisture.
You may find a couple of coats of paint will fill these at first but, over time, as the paint film loses its flexibility and because of natural movement, the cracks will usually open up again.
Painting exposed garage wall?
I have a good condition single block garage wall that I want to waterproof without the expense of rendering. I wondered if Pliolite paint or something similar might do the job?
The wall faces East so doesn’t get much rain. It has been protected by next doors garage for 15 years but they have just knocked it down, hence the need for some protection.
Regular masonry paint will do the job just fine; you may need 3 coats to get a decent ‘weatherproof’ (not ‘waterproof’) result though.
There are some silicon based products which claim to offer a waterproof solution but these are not advisable because they will also trap any moisture that’s already below the surface or any moisture that gets in subsequently via hairline cracks. Ideally you want the walls to breathe and water based masonry paints do this perfectly well.
Pliolite paints are for situations where there is a likelihood of rain falling shortly afterwards, they don’t offer superior protection. For a domestic situation I can’t think of any reason why a pliolite coating would be necessary.
Conflicting advice about which exterior paint to use?
HI, we are rendering our house for the first time next week and I am confused about what paint to apply as I am being given different advice to different decorators.
We live right by the seaside as well. I have been recommended to put a Pliolite by one decorator and the other says Dulux Weathershield. what would we need to prime/undercoat fresh new render with?
Pliolite paints have a quick drying formulation which makes them ideal if it is likely to rain soon after application. For a normal domestic situation this shouldn’t really be a problem?
Regular water-based masonry paint, such as Dulux Weathershield, should be perfectly adequate. For new render it’s a good idea to thin the first coat by up to 20% to ensure good adhesion.
If you want to get the best possible performance Dulux do a ‘maximum exposure’ masonry paint especially formulated for coastal environments.
Our builder suggested Pliolite?
We have a 1912 single brick terrace. The builders have just finished work at the back of the house. The work included a new insulated floor, new windows and doors, DPC injecting the walls and removal of the internal plaster, scratch coating followed by insulated plasterboard dot and dabbed.
This has been done to try and make the house warmer and resolve the damp issues we had. I am now aware that to make all this internal work last I need to get the treatment of the exterior walls correct.
The walls are lime/cement render with many patches of just cement render some old and painted, some new and un-painted (blocked up door). There are many cracks to fill (exterior filler) and some blown areas I intend to remove and skim with a lime, concrete and sand mix.
The painted areas are flaking and when scraped off have green algae behind. I will remove as much of this flaking layer as I can and treat with a fungicidal wash.
The builder suggested that I use a pliolite paint to make the whole area ‘water tight’ but having read through your information I’m not sure this is correct. I was also planning to paint internally with a vinyl paint but again I am now unsure.
Pliolite paint is often more expensive and sounds good. Builders like to recommend stuff on this basis alone. However, it won’t make your building ‘watertight’ and is not an appropriate option.
I think the use of regular masonry paint is the best way forward for the walls as you describe them? You obviously already know what preparation work is required on this front.
Internally, you are right to be concerned about the use of vinyl based paints. In an ideal world the walls should be finished with a lime based plaster and decorated with a breathable paint.
You say, however, the walls have been lined with plasterboard. Without knowing why this choice was made or the details of the installation I can’t say whether this was a good idea or not?
I would still avoid vinyl paints though as you want any moisture to be able to evaporate through the surface. Depending on the details of the internal lining this is going to range in degree – it’s never going to be zero. So anything you can do to mitigate this is to your advantage.
Re-painting exposed concrete gables
I need to repaint concrete roof barges on the gables. They were painted 2-3 years ago with Dulux Weathershield. This has not lasted well, they are very exposed and have missed/alaged over in places…also a couple of cracks need filled.
They are difficult to access and I would like the finish to last. Should I use Pliolite…and what is suitable for the cracks.
Pliolite is a finish that cures quickly so it’s most suitable if you’re worried that it will rain very soon after application – it has NO other benefit and will actually perform WORSE overall than regular masonry paint.
If surface water is not being adequately shed you are always going to have a problem with moss and algae growth, regular cleaning and repainting is about all you do. The cracks can be filled with any external grade filler or an epoxy resin based filler for a more durable result.
We have a newly rendered wall which I would like to paint – having read pages of conflicting advice on the internet I’ve found myself confused…
As it is rainy October do I use Pliolite Masonry Paint and do I need to seal the wall first? The area is the size of a garage door but has a window in it.
Thank you in advance for your help.
You are correct to choose pliolite if you are worried that it may rain soon after application and, in normal circumstances, you don’t need a primer. Just slightly thin the first coat with white spirit.
However, this is only if you absolutely have to paint the wall now and can’t wait until next summer when the weather is going to be more predictable. Ordinary water based masonry paint is a lot easier to work with and is a fair bit cheaper too.
There are often commercial reasons why a job must be done outside normal conditions and this is why products such as pliolite masonry paint exist. For domestic use, when you can do the work at your leisure, it shouldn’t be necessary.
Using pliolite over spar-dash
Hi there, i have a 60s house with spar dash, not been painted before. Can you use pliolite over spar dash? Was not sure if spar is porous at all.
You can paint with pliolite or regular masonry paint, the result won’t be much different although pliolite is going to be messier and a lot more expensive. I’ll assume you have a good reason for choosing this?
The real problem you’ll have is with the different porosity of the materials. Spar dash, as you rightly suggest, is not very porous at all while the cement it is stuck to is, very much. You have to be careful, therefore, that you thin the first coat sufficiently that it soaks into the cement but not so thin that it doesn’t adhere to the spar dash.
It’s a case of doing a small area first and experimenting a bit. Use a trade quality paint rather than a DIY version and be conservative with the amount of thinners you apply at first; start with a little and keep adding until you get a reasonable result. The second coat shouldn’t need to thinned at all, if at all possible.
More information about Pliolite paint?
Where can I find a description and perhaps a review of pliolite masonry paint?
Pliolite is a type resin originally formulated by Goodyear in France. It’s advantage in regards to masonry paints is that has good resistance to humidity and can be applied all year round.
Repainting Over Pliolite Masonry Paint
Can you paint water based masonry paint on top of a pliolite based paint or do you need to strip it off and start again?
Provided the existing coating is in reasonable condition you can paint over with ordinary masonry paint.
Can I use ordinary masonry paint?
External brick walls to my house, painted 16 years ago with a Pliolite based masonry paint, I have just completed some alterations and making good to the property, can I use a water based masonry paint over the old paint system?
Yes Kelvin, as per the previous answer, if the existing coating is in reasonable condition ordinary water-based masonry paint will adhere perfectly well.