If I HAD to paint brick, then satin for sure.

Thanks everyone for the suggestions. Anyway, I have asked the paint folks at SW. I just think it's best to hear as many views/suggestions as possible before moving forward.

David Jensen, thanks especially to you. Good info! I appreciate it.

Ic103 did you ever end painting your exterior brick? If so what sheen did you use Flat or Satin?

Hey there, yes we did end up painting our exterior brick and we actually decided against latex/acrylic paint and went with a mineral paint. It's called Romabio "Biodomus 1". It was so easy to apply, and we are very happy with the results. The good thing about the mineral paint is that it allows the brick to breathe. It doesn't coat the brick, but essentially becomes part of the brick, as it crystallizes to the brick. You should check them out, "ROMABIO". They are very friendly people, and like I said, so far, so good. We are happy with the way it came out. It is a very flat finish and looks fantastic. If any more questions, please feel free to ask. I'm so glad we decided to do this.

lc103 I would LOVE to see a photo. We have a brick and hardie board home. My husband badgers me about painting the brick, but I am hesitant. I'd love to see how your darker color turned out!

Oh yeah, we actually ended up not going with the darker color and ending up doing the Romabio Biodomus 1 in a colormatch of Sherwin Williams Pure White. It was a perfect color match. I would definitely not hesitate in painting the brick, like I said if you use the mineral paint, you really have no worries. We've been here for 15 years and I wish we would have done this 15 years ago! Romabio can match colors and they also have a color deck of their colors. They do interior paint as well, it's a good company. (I swear I don't work for them. ha...) It was fun painting, I was so happy watching that ugly red brick disappear. And it was such an easy paint to work with. Go for it. You will not be disappointed.

Hello lc103, I have been contemplating using Romabio for about 6 months! Nobody in town seems to be willing to work with the product so it's been tough. I finally found someone who is willing to the work. Did you only paint the brick with Romabio or did you also use it on other surfaces? I have old shingles that need to be painted as well but not sure how it will turn out. So glad to hear your comments!!

Hi Kay, I don't know why nobody in town wants to work with it, it's the easiest paint I've ever worked with. It's probably just because they are not familiar with this type of paint? Our house is one-level, so it wasn't a difficult job to do ourselves. We only painted the brick. I'm not really sure about shingles, I'm assuming these are old cedar shingles? If you give the folks at Romabio a call, they'll help you. They also have some "how to" videos on their youtube channel, as well. Good luck and I hope you decide to go with the Romabio. Like I said in a previous post, we are absolutely thrilled with the results.

Okay we are going for it! Thank you for your input!!

Well yall beat me to it - to prevent damage to the brick long term it really does need to be some sort of mineral paint -Limeworks and Keim USA are two other US sources, fwiw.

I too have had difficulty finding anyone local for my project so Im just going to DIY - its not rocket science. Youd think there would be someone interested in learning about it and expanding their skill set.... but no! Maybe theres job security in knowing that when the paint peels in a few yrs youd have to hire them back to do it again.

Completely agree CR! It is so frustrating that they are stuck in their ways on paint. I'm thinking it could be a new business venture :)

Thanks all for the support! You can learn about all of our finishes for masonry at romabio.com/masonry. We also have other products that work on wood and other surface types, but they are better for the Interior. Definitely call us at 678.905.3700 if you have any questions. Happy Painting!

Hey Romabio! What can you do about helping me tell all these posters on this forum not to slap latex paint on their brick. Its kinda wearing me out trying to keep up with all of them LOL.

flat on brick, satin on doors/trim

Current Resident... love it! It's amazing the little awareness about acrylics vs mineral paints for masonry. So many more people are Painting brick now which is a great way to update and beautify your home. Because brick is porous and a natural material, it wants to breath and our paints let it. We tell people that using acrylics on it is like sealing it with a plastic coating so imagine what issues that could cause. Keep it up and thanks for the help!

This might be a case of too good to be true. "brick is porous...it wants to breathe" I have seen several occasions over the years where porous brick has caused damage to homes precisely because it does pass moisture into the wall cavity or to abutting wood structures, causing rot to windows and wooden sills.

If you live in a warm humid climate and have a brick exterior, don't hang impermeable wall coverings on the inside walls if the house is air-conditioned! Also, don't have visqueen behind the drywall. Why? Because the humid air gets to the cool interior surface of the interior wall and condensates, rotting the drywall and wall interior. I have personally had to rebuild the lower half of a living room wall where the owner had hung metalic wall paper on the two storied wall. The upper portion had wood siding on the exterior and was fine. The lower wall had brick on the exterior. The lower wall had to be completely opened, and all the drywall and insulation replaced after drying it out. Porous brick had passed moisture into the wall and the metallic wallpaper trapped it there. Solution? Seal the exterior brick against moisture penetration and don't rehang any wall paper on the exterior walls!

Porous brick needs to be sealed against rain intrusion, be it clear silicone type sealants or paint.

"Acrylic paints don't breathe" Wrong! Acrylic paints shed flowing rain water, yet have a very good perm rating. This is precisely why they were a quantum leap as exterior house paint over oil paints. Oils do not breathe well and multiple coats over the years finally caused wood siding to peel as it formed a vapor barrier on the external surfaces of the siding, trapping moisture in the wall cavity. This is also why acrylic/latex paints were favored over oil when coating brick.

David, no argument from me - except fyi mineral paints (eg limewash, potassium silicate. etc.) do repel rain, but let water vapor pass thru (ie breathe).

I have no argument with mineral paints, only the denigration of acrylic paints with less than truthful statements. Properly applied, acrylic paints should give years of service on masonry surfaces.

ALL acrylic resins fall under the category vapor retarder which has multiple classes. They are not designed for permeability. In fact, products like Loxon and Loxon XP can fail low on the building after 6 months to a year because they were applied too soon after a recent rain. In fact a neighbor of mine is suffering from this now because the paint crew rushed the job and now they have to come back repeatedly to fix the failing areas. Of course acrylic paint can last for 5 to 10 years, if the substrate was adequately prepared. Potassium Silicate based mineral paints have perm ratings above 70 which is considered high permeability. Tyvek wrap has a perm rating of 58. The highest acrylic rating I have ever seen was <6, and it was a specialized resin formula that was considered non-bridging technology for acoustical invisibility. Potassium Silicate mineral paints can last two, three or even 4 times longer because they are calcifying to the brick and allowing vapor pressure to easily pass through the milage of paint. If you would like I can get into Kunzel theory and show videos as well......Best, Michael

And no one is denigrating acrylic paints. We are all merely pointing out that for masonry surfaces there is a much better system......that, by the way, has no sheen which on masonry looks much more authentic than a shiny brick covered by acrylic resins.

I'm confused. I thought acrylics = latex paints.

bossyvossy, acrylic paint and latex are interchangeable.
Mineral paints are not acrylix/latex paint. They can be potassium silicate paint, sodium silicate paint, slaked lime paint, hydrated lime paint and hybrid versions of all of these combined with high pH stable resins.

Acrylic/Latex uses acrylic resins as the main binding agent. Mineral paints use potassium silicate, sodium silicate, slaked lime and hydrated lime as the main binding agents (calcification).

Thank you

"Latex" has become a generic term for water based paints. There has not been a true latex paint on the market in decades, to my knowledge. Back in the 40's when latex paints were introduced, they literally had natural latex resin in them. 100% Acrylic "latex" resins are generally considered state of the art for today's flatwall house paints. Of course, there are many variations of blends with lesser resins, but pure acrylic excells in the combination of adhesion, elasticity and permeability.

Not all water soluble paints would come under the term latex, such as water based alkyds and epoxies. These exhibit different characteristics for special purposes, for instance, both are far less permeable than acrylics. Alkyds hard surface lends itself to cabinetry and furniture, that where acrylics come up short.

Michael,

Your sample on the left is "vinyl acetate" ( as in PVA , poly vinyl acetate) a "latex" but NOT a true acrylic. Elastomeric acrylic based masonry paints will typically have perm ratings of close to 10. They will also readily shed rain water, not raising the moisture content the masonry or stucco beneath.

Having lived in Germany for several years, I am familiar with Keim paint and its suitability for the predominantly solid masonry, stucco finished housing stock, especially built centuries ago, before insulation, vapor barriers (retarders )and central heating. It is a good coating for these structures.

I have no problems with Keim paint in general for brick on American homes, especially older homes built before today's environmental standards against moisture transfer. Neither do I have problems with acrylic based masonry paints for these newer structures. Even here, there are exceptions, as in the example in my prior post where permeable brick had contributed to the wall failure in a house with impermeable wallpaper on the interior of an air-conditioned house. Water vapor will always try to even out the moisture differences on both sides of a permeable barrier ( typical wall construction). Climate and heating/air-conditioning norms determine the wall construction in different parts of the country. What is good for Florida is not good for Arizona. Where a vapor barrier is placed ( if at all used) is the variable.

David, Here is a tutorial on PVA...http://pslc.ws/macrog/pva.htm....check out the last paragraph....I'll just post it for you -

Now ask yourself this question. If you were a molecule of PMMA, and as a PMMA molecule you hated water, where would you go? Would you go out into the water, or would you go into the inside of that coiled polymer, away from the water? You'd go to the inside of the coil of course! And that's just what the real PMMA does. The PMMA hides in the hydrophobic center of the coiled polymer. By doing this, it can stay suspended in water based paints! A suspension of an insoluble substance, like PMMA, held in suspension by being wrapped in another kind of molecule, like our copolymer, is what we call a latex. That's where we get the name latex paint.

And just in case you didnt take Organic Chemistry in College PVA is made of monomers called vinyl acetate.

And, guess how many times paint is mentioned in the article......wait for it.....14!!

With perm ratings of 75, you are reaching the point where moisture can be passed into the brick. If the brick can absorb moisture, you are asking for a whole litany of problems. I gave an example of how moist brick had rotted out the drywall in a home. The cedar siding above with solid hide stain did not pass the moisture and was fine. If you are interested in the phenomenom of "sun driven vapor", read the attached link:

www.greenbuildingadvisor.com/blogs/dept/musings/when-sunshine-drives-moisture-walls

Your assumption is that if a paint does not peel, all is great in the wall. It ain't necessarily so! Ask my customer who had to re-build the moisture saturated living room walls cause by porous brick passing moisture into the wall cavity where it was trapped by metallic wall covering on the inside walls.

One way or the other, the exterior brick should have a water/vapor retarder, be it acrylic, clear silcone type sealants or Keim paint. Where additional vapor barriers ( retarders) are placed depends on the local climate. Such retarders can be visqueen, sheathed insulation, or vapor retardant paint.

Michel,

To quote from your linked article,"It (acrylic) is similar to PVA, but it is different"

What makes acrylics acrylic is that they are derived from acrylic acid. Acrylic paint is a kissing cousin of Plexiglas. I am kind of interested in the history of acrylics since they were invented in the 1920's by Rohm und Hass Gmbh in my wife's home town of Darmstadt, Germany. I actually would drive by their headquarters daily when I lived in Darmstadt. Rohm, as it is simply now known, is one of the major suppliers of acrylic resins to the paint and coatings industry.

As I have said before, there is such a thing as 100% acrylic paint, but acrylic is often blended with lesser resins such as acetates, usually to lessen the price point, just as lesser pigments than titanium dioxide are used to lessen the cost.

Keim, is not merely a generic term for silica paints, but the German company which invented this type material and it is still in business making the newest version of its silica paint which dates back 130 years.

Keim paint was often the "Putz" which was put on stucco to freshen it up.

The brick itself is not the problem. It is what moisture transfer does to surrounding materials and interior wall cavities which are subject to moisture degradation: windows, wooden sills, insulation, drywall. Although, highly porous brick is subject to spalling, just as is poured concrete.

One way or the other, porous brick should be sealed, be it paint or clear sealants. It must also be periodically tuck pointed, the mortar also subject to moisture degradation. Badly degraded brick was often "parged", having a thin coat of mortar troweled over the whole surface. I grew up in Chicago, where since the Great Chicago Fire, the whole town was constructed of brick by law. Tuckpointers had no lack of business there.

I am not against any product that prevents rain water from entering, but allows moisture from any source to permeate outward. To this extent, brick is no different tan wood construction.

SCIENTIFIC DATA FOR ARCHITECTURAL
COATINGS APPLIED TO BRICK

Very interesting comments in regards to acrylic versus mineral paint applications on brick. No paint product can overcome construction defects or designs. The wrong type of paint can cause damages to external or internal building systems or to the substrate to which they have been applied. The more permeable a paint product, applied on masonry, is historically for brick the most desirable result.

The American brick industry does not embrace architectural coatings that reduce the permeability of a brick veneer. Water resistant paint coatings are embraced, which is possible with either acrylic or potassium silicate paints. Another primary concern with the brick industry is durability. The durability charts for acrylic paints applied on masonry provide a 5 - 7 year durability ratio. Potassium silicate paints provide a ratio of 10 - 40 years, and historically have been noted to endure for up to 100 years.**

I will post quotes and tables from links provided in this comment to avoid as few personal comments as possible, educating the readers to come to their own conclusions.

**Mineral
silicate paint coats are considered durable and weather resistant. Lifetimes
exceeding a hundred years are possible. The city hall in Schwyz and
"Gasthaus Weißer Adler" in Stein am
Rhein (both in Switzerland) received their
coats of mineral paint in 1891, and facades in Oslo from 1895
or in Traunstein, Germany from 1891. .https://en.wikipedia.org/wiki/Silicate_mineral_paint

https://ktauniversity.com/significance-permeability-paints/

The
Significance of the Permeability of Paints

Permeability of Applied Paints
& Coatings… Do I want a permeable coating or not?

The answer to the question
posed is based on the substrate and the service environment. All paint and
coatings are permeable to water, just to different degrees. A high resistance to
permeability is likely desirable for lining applied to the interior of a tank
or vessel; however, a paint system applied to the exterior of a masonry block
building better be “breathable” to allow moisture in the block to escape.
Otherwise blistering and peeling will likely occur.

What is water vapor
transmission or WVT, the Water Vapor Permeance or WVP, and the Water Vapor
Permeability?

These three terms are used to
describe how quickly water vapor diffuses through a solid material. The
Water Vapor Permeance is often simply call the permeance, and the water vapor
permeability is often simply called the permeability. The Water Vapor
Transmission (WVT), permeance, and permeability are very closely related in
that one is calculated from the other. First the WVT is determined. . Then the permeance is calculated by dividing the
WVT by the vapor pressure across the material under test. The permeability is
calculated by multiplying the permeance by the thickness of the material.

What is water vapor?Water vapor is the gaseous
phase of water. In the gas phase, water molecules move very rapidly and
are not bound together. Water vapor can be produced by the evaporation of water
or the sublimation of ice or snow. It can also be produced by the boiling
of water, but the steam that you can see coming out of your kettle technically
is not water vapor. Water in the gas phase is invisible. The steam that
you see consists of very small droplets of liquid water suspended in air.

What does the magnitude of the
permeance indicate?

Materials can be classified by
the magnitude of their permeance as follows.

§ Vapor Impermeable: less than 1 perm

§ Vapor Semi-permeable: between 1 and 10 perms

§ Vapor Permeable: greater than 10 perms

https://buildingscience.com/documents/information-sheets/building-materials-property-table

Type of Material Water Vapor Permeability (permeance-Inch)1 Wet Cup

Brick 1.7 - 13.7

____________________________________________________________

Exterior Acrylic Paint 5.5

Semi-gloss vinyl Acrylic Enamel 6.6

Potassium Silicate Paint

Lime Paints No reduction. Equivalent to that of the substrate

Potassium Silicate Paints 20 - 65 * or equivalent to that of the substrate

*The permeability for water
vapor of silicate paints is equivalent to that of the substrate. This
effectively means that silicate paints do not inhibit the diffusion of water
vapor. Moisture contained in parts of a structure or in the plaster may diffuse
outward without resistance. This keeps walls dry and prevents structural
damage. This addition helps avoid condensation water on the surface of building
materials. This reduces the risk
of infestation by algae and fungi. The high alkalinity of the binding agent
water glass adds to the inhibitive effect against infestation by microorganisms
and completely eliminates the need for additional preservatives. https://en.wikipedia.org/wiki/Silicate_mineral_paint

THE BRICK INDUSTRY ASSOCIATION

http://www.gobrick.com/portals/25/docs/technical%20notes/tn6a.pdf

Water Vapor Transmission Rate and Permeability The most important property to
consider when selecting a coating for application on exterior brick masonry is
the water vapor transmission rate. The water vapor transmission, or
breathability, determines the rate and amount of water that can evaporate
through the face of the brickwork. Coatings that have low water vapor
transmission rates inhibit evaporation and can trap water within the brickwork…

Low
water vapor transmission may also result in the premature deterioration of
brickwork. Water that is unable to pass through a coating increases risks of
masonry deterioration due to freeze-thaw cycles and deposition of water-soluble
salts behind the coating. As these salts crystallize, they grow significantly
in size and can create enough expansive pressure to cause spalling of brick.

L C If you have a picture of your house that you're willing to share, I'd love to see it. I was looking at Sherwin Williams before I ran into the Romabio line, and the pure white was what I was planning on going with.

Hey badeezdee, I added a pic to one of my ideabooks that is set to private but I invited you (or added your name as a collaborator or whatever). So, hopefully you can click on my name and you will have access to it. It's not the greatest pic, but it is the Romabio Biodomus I in a colormatch of SW Pure White 7005. We absolutely love it. It's only been a year, but it's held up very well and no problems, and it has actually stayed very clean, which was a bit of a surprise. Again, I could not be happier. It's one of the best things we've done to the house. The Pure White is a great white, in my opinion. It's clean, crisp with no yellow-tones or blue-tones, no pink-tones, It's just... white. :-)

If you have any troubles accessing the pic, just let me know.

L C Thank you! It looks great - a really clean white but not too stark.

L C do you mind sharing a pic of your home? We are considering Romabio but I have shakes and siding along with brick to paint.

riktha LC shared a picture with me, so she may share one with you as well. I'll also mention that I have put in the hashtag #whitebrick and #whitebrickhouse on instagram and have seen lots of great examples. You can also go to the romabio website, and click on their masonry link, and each line has a lot of pictures as well. Lots of great stuff out there!

HI riktha, no problem. If you click on my name you should be able to access the pic in my ideabook. I added you as a "collaborator" so you should have access. Good luck with your project. Also, I would suggest (as badeezadee did) to go to the romabio webste as well. They have really good pics on there. The people there are really friendly too, if you have questions. I was scared to do it myself (I'm not sure why... I thought I was going to put it on wrong or something ...lol.) But it was super-easy to work with. So much nicer to work with than regular paint. It's thin and spreads really well and covers wonderfully.

I apologize for the length of this post....but, for the benefit of anyone still reading this above discussion about permeability of various brick coatings, I would like to add my experience dealing with leaking substrate to help others, I would hope, and conclude with products I've found to work somewhat. And I realize this isn't my original post, but I end my statement with a question for those with opinions on how we all go about letting brick breathe that is also letting water in! In my opinion, the two gentlemen discussing waterproofing brick vs. letting it breathe are both correct. So, it just depends, and it's almost a catch -22. I'm remodeling a large, modern home. My brick and mortar are very porous. I know Rilem Tube testing can be inconsistent and tricky, but the water placed in the tube soaks right into my brick and mortar very quickly. We did the Rilem Tube test on each - - mortar and brick. I've had large commercial waterproofers look at my situation, as well as a smaller waterproofing company with many years of experience in residential. I've had roofers and brick masons investigate. We have an area gutted in the garage where we can see the back side of the brick. The plywood sheeting was rotten on the studs when we gutted this area. Keep in mind this is a modern home designed and owned by an architect. He decided it would be a good idea to have a brick upper porch by his front door. This upper porch also extends around the side of this house OVER the first bay of the garage - -which is where we have gutted from the interior. Wow..bad idea on the architect's part. By the way, we're "peeling layers" in various areas of the house to fix many things including this porous mortar/brick. There is no Tyvek on the house (about a 25 year old home). Just felt paper sheeting over the plywood. Water testing with power washers and water hose have been done on the roof, at windows, etc. We've gutted other interior areas of the home and haven't discovered any damage to the interior walls. We've never had water coming into the house - -even at the basement level. However, in another area of the garage (not under a sidewalk!), I have seen water on the floor after days of hard rain. The brick/mortar is simply leaking when there is a wind driven rain or if it pours rain for consecutive days. I've done extensive research on permeability (WVT etc). I've always believed we should let brick breathe. I've heard so many nightmare stories where brick wasn't prepped or painted correctly, or perhaps a leak was coming from the roof or a window and getting behind painted brick. I've also researched Romabio mineral paint and love the product; however, I have to stop this water penetration. So, I've proceeded with products from Foxfire Enterprises Inc. (based in San Antonio). They have brick/concrete cleaning, as well as waterproofing products. The cleaners are amazing by the way. Their products are environmentally friendly and apparently you can even drink the cleaning products (wouldn't try that, but the company owner has!). This company was hired to waterproof the Playboy Mansion and went up against other waterproofing products in a test before they were the ones selected to do such a huge and historically significant job. Furthermore, every Walt Disney World building is now "spec'd" with Foxfire. Meaning their builders are required to apply Foxfire products to their buildings. The product I've used penetrates the mortar up to inches and hardens like glass. We've had to come back with two coats on that area below the sidewalk (which is above the garage door). So far it is stopping most of the rain penetration but not all. The penetrating sealer needs a certain amount of mortar in the vertical joints between bricks to really take hold. Some of mine don't have that. Furthermore, the brick itself is porous and this product doesn't leave a coating on the brick. Some of it penetrates, but not much. So, apparently I've sealed up the mortar but not the brick, at this point. We are probably going to apply a third coat of the penetrating sealer around this problem area and see if third time's the charm. We've looked for cracks, but maybe we're missing something. The penetrating sealer does span small hairline cracks, but again, we may be missing something. I'm also going to do a test in a more simple (just vertical brick) area on the other side of the garage to see if I can get water to penetrate and show up on the floor. So what about the actual surface of the brick? If you use a Foxfire penetrating sealer, you need to top coat it with their "surface sealer" (which needs to be reapplied probably every 5 years). Then you've actually waterproofed the brick, in addition to the mortar (which really needed that first step of applying the penetrating sealer). Instead of doing step 2 and applying the "surface sealer", the other option is to prime/paint it after you've done the penetrating sealer. This is where I'm at. I know the penetrating sealer isn't stopping every drop of water. I'm going to call the company and see how permeable the surface sealer is. I know the perms of the various primers/paints. And you're right, they aren't very "breathable", but I'm not sure I have a choice. I bet if I use Loxon primer or Loxon Block Surfacer primer and then Sherwin Williams Duration exterior latex, I'd stop the water penetration. I also know my brick/mortar won't breathe very well if I do that. If water somehow gets behind the brick in the future (roof leak; window leak etc), I'm in trouble. I also don't know if Romabio would work over the Foxfire penetrating sealer. Apparently the Foxfire penetrating sealer doesn't leave a coating on the surface, but Romabio also needs to penetrate into the mortar from what I've read. I would like to see these two Texas companies work together and test their products' compatibility. I'm not planning on using any metallic wallpaper, but I was going to use some wallpaper in bathrooms, for example. Now I'm reconsidering that because I'm not sure if any wallpaper breathes (metallic or not). We are tuck pointing a few areas. And yes, we are also using NP1 caulk in a few areas. This caulk is pretty darned solid. I'm confident it will last a long time, but by using it, you're creating future maintenance. If this caulk fails, I know...water will go in and now the brick is sealed up and not breathing that well! So, let me pose this question....what if you water proof your brick as David Jensen suggests above, but you place a large number of weep holes around the perimeter of your house and above the window lintels to at least allow for some "breathability"? Anyone want to chime in on that method? It's been a long process off and on for two years for me to come to this conclusion. If anyone has experience who can help others, I'd love to hear. Thanks.

By the way, SW Loxon Block Surfacer has a WVP "perm" rating of 42.2. SW Duration has a WVP "perm" rating of 21.1. So, this isn't too bad. It's not in that 10 range discussed above for acrylic paint.

The "Holy Grail" for any coating, whether for wood or masonry, is to repel flowing water, yet let water vapor pass on through.

Ihearnew, I've used Sonoborne Urethane NP-1 caulk for years as my go to caulk. As a urethane, it actually needs moisture to cure properly. It is elastic and sticks tenaciously.

Wallpapers almost all have a plastic coating on them, presenting a vapor barrier problem. In the instance I have mentioned, it presents problems in hot, humid climates where the house is air-conditioned. High school physics teaches that warmth and humidity try to equal themselves out on both sides of a barrier. In place such as Florida, that moisture gets to the cool inside ( back side of the drywall) wall and condenses on it, often to the point of flowing down and doing damage.

Wallpapers are fine on interior walls, just problematic on exterior walls subject to great differentials of heat and humidity. Rule of thumb: if you can't keep vapor from entering a wall cavity, don't put any barrier to keep it from exiting.

I dont know about this product - cant speak for them but I have tried out the potassium silicate paint I intend to use on my crumbly old brick - it is a different animal from regular house paint and a bit of a learning curve I imagine. I think theres a type of brush they recommend that might make application easier. The runniness might have to do with the fact that this type of paint is not a film that sits on the surface - it penetrates and chemically bonds with the minerals in the brick or stone.

@L C can yiu share photo or add me

to your list to see your finished product?

Acrylic latex paints are the best to use for painted brick because they're more flexible than oil-based paints but they're still very durable.