EIf you’re looking for the best paint to cover and block stains, you’ve come to the right place. As a professional decorator, I’ve worked on many properties that have been plagued with unsightly-looking stains.
Whether your stain is caused by nicotine, water damage, or fire damage, there are plenty of products currently on the market professing to be the solution.
But which ones should you trust to do the job? Fortunately, I’ve used many different brands and stain-blocking paint in my time so I’ve decided to give you my recommendations as well as recommendations from people I know within the trade.
Ready to find the solution to your annoying stained walls or ceilings? Read on!
Does Stain Blocking Paint Actually Work?
In general, stain-blocking paint definitely works. As a water-borne primer that has been designed specifically to deal with stains on walls and ceilings, stain-blocking paint frequently prevents the migration of stains from the substrate through the top coats.
Furthermore, stain-blocking paint can even be used to bind friable surfaces such as plaster.
With that being said, when it comes to stains caused by damp, it’s best to remedy the source of the problem otherwise the stain will return in the future.
Nicotine stains can also be somewhat problematic to cover with stain-blocking paint but there is a simple solution to this – always wash the walls with sugar soap before applying a coat of stain blocker.
Best Stain Blocking Paint Overall: Johnstone’s Stainaway Matt
I know some professional decorators might disagree with me on this choice but for me, nothing beats Johnstone’s Stainaway Matt when it comes to blocking stains on walls and ceilings.
When I think about regular DIYers having to professionally cover stains on their walls and ceilings, it makes me slightly nervous. Fixing stains is a tricky process. For example, using a stain-blocking primer can affect how quickly future top coats dry and that’s just one thing that could affect how good your walls and ceilings look after you’ve finished decorating.
But with Johnstone’s Stainaway Matt, you’ve got a primer and top coat in one and most importantly, one that actually works.
I’ve used Johnstone’s Stainaway Matt on plenty of jobs – it’s trade standard and it seems like Johnstone’s has really cracked the technology to isolate stains and ensure they never come through. Of course, there have been odd occasions where it didn’t quite work but this was mainly down to conditions out of the paint’s control.
It works on nicotine stains, grease stains, and water damage amongst others so you can be confident that your walls and ceilings will be stain-free for years to come.
In terms of drying time, it’s touch dry within an hour and more importantly can be recoated after just 4 hours. Such is its opacity and ability to combat stains, some jobs only need one coat.
Furthermore, it comes in a matt finish – the kind that covers blemishes, so even if the stain does peak through, the matt finish is likely going to go a long way to conceal it.
Pros
- There’s no need to deal with a primer/top coat paint system as this is a 2-in-1 solution
- Recoatable in just 4 hours which means you can get your walls and ceilings looking good in less than a day’s work
- Great opacity means you can sometimes get away with just 1 coat (although sticking 2 coats on is recommended)
Cons
- None
Final Verdict
It’s a simple paint system ideal for DIYers to cover their walls and ceilings within a few hours – what more do you want?
Trusted By Professionals: Zinsser Coverstain
Zinsser Coverstain is perhaps the most widely used stain-blocking paint among professional decorators and for good reason.
It covers most stains with a high degree of efficiency although I have had trouble in the past using it to permanently cover water stains, especially if spot priming. With that in mind, if you are going to use this to cover water stains I would recommend applying a coat over the entire wall/ceiling.
Other than the issues with covering water stains, I would say that Zinsser Coverstain is the perfect solution for things like covering nicotine and grease stains – perhaps even better than Johnstone’s StainAway due to its thickness and opacity.
Furthermore, Coverstain barely ever flashes which can be a common issue with some stain blockers thus revealing where you covered the stain.
With its amazing adherence to walls and ceilings, you can be confident when painting over any stain.
Finally, Coverstain dries to a rock-solid finish unlike some other stain-blocking paints which can sometimes dry to a brittle finish and cause issues such as paint flaking.
Pros
- The thickness of the paint means it covers stains with ease
- Never flashes through emulsion
- It’s highly versatile and can be used on a variety of substrates, both interior and exterior
Cons
- Sometimes has trouble blocking water stains
Final Verdict
Whilst I’ve encountered a couple of issues with Zinsser Coverstain, it’s undeniable that it is a great stain-blocking paint used by countless professional decorators. Make of that what you will!
Best Stain Blocking Paint for Wood: Coo-Var Shellac Primer
Coo-Var Shellac Primer is a somewhat new addition to the shellac primer/stain block market but has gained a foothold amongst professional decorators as their go-to exterior wood stain blocker. And whilst it’s not exactly perfect, there’s very little to separate it from Zinsser BIN in my opinion.
Just like BIN, you can use this primer to prime surfaces where paint adhesion is sub-optimal (think painting over sealants for example) which basically means the paint is far less likely to crack or flake.
Crucially though, it’s also highly recommended for spot priming and sealing knots and stains on exterior wood. Here’s an example of how I used Coo-Var’s Shellac Primer to treat failed knots on the exterior of a front door:
I also found that this stain blocker is incredibly quick to dry (around 15 minutes or so, although Coo-Var suggests 30 minutes before applying the next coat in your paint system) and a bit more scratch-resistant than other stain blockers.
Overall, the Coo-Var Shellac-Based Primer is slightly better than Zinsser BIN which can sometimes flash through the top coats and yet is slightly cheaper so if you’re looking to block stains on exterior wood, this would be my recommendation.
Pros
- Dries extremely quickly allowing you to get on with the job almost instantly
- Cheaper than comparative products
- Consistently blocks stains and resin from re-appearing
Cons
- None
Final Verdict
This is my preferred alternative to Zinsser BIN. It does all the same stuff yet is cheaper and very rarely flashes through the top coats.
Other Options
In my opinion, you’re better off using a specific stain-blocking paint to give yourself the best chance of eliminating the stain for good, there are a couple of other options that some professional decorators swear by.
One of those options is to use Stormshield Pliolite Based Masonry paint as a primer. Decorators sometimes use this on top of walls that have been stained by damp and in fairness, it does typically block the water stains from coming through. However, if you’re going to opt for this option, bear in mind that it is a solvent-based paint.
It absolutely stinks and can be harmful when applied indoors so therefore I wouldn’t recommend using it.
Another option is to use a classic oil-based undercoat. Many old-school decorators prefer this tried and tested method because typically, it works.
Being solvent-based, the undercoat covers stains easily and creates a protective barrier from those stains coming through in the future. Furthermore, it gives great adhesion for your top coats.
The downside of course is that it’s not exactly environmentally friendly and gives off VOCs (albeit in small, safe quantities). You’ll definitely want to air out the room before, during, and after using the oil-based undercoat if you go down that route.
What Causes Stains?
Some of the most obvious causes of stained walls and ceilings include:
- Damp
- Mould growth on the surface
- Nicotine if cigarettes have been smoked indoors
- Felt-tip markers
- Grease
Frequently Asked Questions
Is Primer the Same As Stain Blocker?
Stain blocker is technically a primer but its specific purpose (obviously) is blocking stains. It’s not advised to use any other primer to block stains as the stains will simply migrate through the primer and top coats.
Can You Use Gloss Paint As a Stain Block?
No, it’s not advised to use gloss paint as a stain block. Whilst oil-based gloss will go some way to covering stains, eventually, the stains will simply reappear.
Can You Use PVA As a Stain Block?
Whilst you can use PVA as a stain block, I wouldn’t recommend it. PVA is a nightmare to paint over as it offers barely any adhesion for the top coats. I’ve heard about plenty of horror shows where people have tried to paint over PVA. Even when it’s been thinned down it’s still a nightmare. My advice: avoid it.
How Many Coats of Stain Blocker Do I Need?
Most stain blockers are formulated to be used as a single-coat primer. However, if you have particularly problematic stains you might want to apply two coats just to be on the safe side.
Does Stain Block Stop Damp?
Stain block can stop damp from appearing through top coats for a limited period of time, depending on how bad the damp issue is. Ultimately, you’ll need to fix the damp issue, stain block should be considered as a temporary fix if anything.