It has never been painted, stained or otherwise treated in any way. You can always prime over the test area. I used white vinegar to remove the mold and then did a full wipe down with water. The main considerations you need to think about are new and unpainted, condition of existing finish and type of concrete block. I am looking to paint a painted cement block townhouse. Do I really need an oil based primer? I bought Behr Dry Plus- Masonry Waterproofer. In a previous post you noted the acrylic block fill doesnt adhere as well to previously painted services. Covers very well, and can be tinted. I have no idea how old they are, but the paint is thick & has crackled/chipped in various places. What do you recommend? Mold along the edge, especially with carpet, is also an indication of problems. Paint will dry better in direct sunlight even when humidity levels are very high. Stripping shouldnt be necessary. amzn_assoc_ad_mode = "search"; And finally, spray or roll? I was planning on caulking tomorrow, but its calling for rain the next few days, so Ill probably wait. Temperature, wind sun exposure all change how fast the primer will dry. The bubbling is a bit perplexing; even cheap paint should go on without bubbling. How about this; Working small sections at a time, spray heavy coat then quickly backroll (keep a wet roller in a 5 gallon bucket with some primer, this way the roller wont dry out). An alternative is to apply a very good paintable caulking over the silicone. Hi there, thanks for this valuable information. Lift off the peeling paint with a stiff putty knife or paint scraper. The elastomeric should stick well over the old paint but the old paint can be primer to make sure there is good adhesion. Use a semi-gloss paint to help with the moisture. If filled in the holes nicely and made the wall much smoother. Lastly, how many coats of primer and paint? And if I do the above, do I caulk it before I prime & seal the block, or after. We can have single digit humidity and paint that drys so fast it cracks if to thick, the surface hardens while the inside film is still a liquid. No need to do anything with the block wall but do double check the landscaping. I have the same situation. Advice appreciated. A spar varnish will be best but sticky and take a long time to dry, chasing drips will be your new pastime. Need advice. I dont know of any other easy to apply product that will look as good as the Roller Rock. Also, look to the cause of water infiltration of your basement walls. Test kits are cheap and available at your local paint store. Any thoughts, tips, anything you can offer? The exposed deck frame no, this should never be sealed. This is a great site with excellent information! I have attempted applying this Glidden paint directly over the previously painted wall, as well as used a Drylok waterproofer and BIN shellac based primer. 3) The paint could be removed with abrasive blasting. Most primers can be tinted to a light gray. The difference of texture will drastically alter the amount of primer and finish paint needed. amzn_assoc_ad_type = "smart"; The mortar still looks wet where the wall has been core filled. A really good foundation primer, below grade, is Drylok. Plain water will remove loose paint and dirt but efflorescence will need chemicals to be neutralized. The poly caulk needs priming with the same oil based primer prior to painting. The question is do we need to use an acrylic block fill on the new cinder blocks and a different primer, like Zinsser 123, on the previously painted blocks? Overnight will work. In order to post comments, please make sure JavaScript and Cookies are enabled, and reload the page. Theres always better primers, STIX by Insl-X is really good but expensive. You seem to recommend Acrylic? This will help. It may not display this or other websites correctly. You can also then, of course, finish the job by applying the right type of sealer that will protect the paint job from the weather conditions, a necessary step for outdoor and exterior walls. I plan to use the remaining dry lock as a block filler for those sections. Hope to use a regular paint due to cost, as opposed to a specialty type. backsplash marble kitchen tile block cinder tiles painting installing subway countertops cabinets mosaic install walls redo carrera dining similar behind This will make it a lot cheaper, and a lot easier, as its just the primer that needs to be specific. 3) We have a ton of red curbs that neednt be red! Again, Thanks, Though now I have another concern. 1. My interior fireplace is made of split face concrete block and its never been painted. Sound like a good plan. I have some Kilz Mold and Mildew Primer and the Restoration Primer. First and foremost, let me thank you for your time and the wealth of knowledge you provide on this site. We put bondcrete on it first than we painted it with water based paint. Paint peeling off caulking is a compatibility issue. Im not trying to keep flood water out, Im just trying to keep moisture out. Choosing a good quality paint and applying 2 coats on everything will help. Im not sure what product was used but understand that it was from a professional commercial line. What is the Best Paint for Cinder Block Walls? Yep, you want to use a block filler type material for the first under coat. P.S. Help, Help, Help!!! Thank you for all your incredible guidance! Do not use an Elastomeric coating. Really tough. Most often, walls made out of cinder blocks will be located and found in the exterior, as they can resist weather conditions really well and perfect for outdoor use. You probably wont need the block filler after priming with the oil based primer as this will fill a lot of pores. A primer is needed. This will give you more predictable coverage for the epoxy. Googled waterlox and all I found was wood finishes. Interior garage walls are unpainted cinderblock which we want to paint. Who ever put it there should clean it up. I am attempting to paint some concrete walls in the basement of our 1965 home. Its a great help and have learned a lot. The goal is to get a seal on the long term blocks so moisture does not make its way through and disturb the tenants offices with leaking. 1) Yes, the block walls can be painted. Older basement 50s, cinder block, Was painted white, with with some areas of Efflorescence. It was painted years ago, I have been pressure washing it. Second to quality paint is quality caulking. The house is old and the concrete blocks are painted (likely in the past 25 years). The existing wall is painted, most likely with an acrylic paint as the paint chip is a regular Valspar paint. Any other tips for us? I dont know their products but buy the best you can afford. Or use your mortar mix, add extra portland cement and lime. The basement has never been painted before. The first step when preparing concrete block walls is pressure washing. I can not imagine that I will ever successfully remove all of the glue. Shouldnt window caulking have been done differently, not attached to loose paint? During the preparation pay attention to any loose mortar and large cracks. It will show. Im torn between using a vinyl wall cover and wallpaper, using portland cement to smooth out the grooves, or just throwing in the towel and tiling over it. Thank you. New unpainted concrete block walls need to have all dirt and loose mortar removed prior to priming. That removed a lot of dirt. What would you recommend? These will not be subject to foot traffic, but they may get stood upon occasionally. Please advise with your experience and wisdom. The power washer can be used to remove loose paint from the block (be careful) but can do a lot of damage to wood. https://www.paclandinc.com/portfolio/culver-city-90232-cmu-slump-block-wall/, 2) We had some sidewalks repaved and there is concrete overspray all over the surrounding natural brick raised planters. How to Use a Paint Sprayer with an Air Compressor. We had a new concrete block addition as well as stuff that had not been touched in 20 years of Florida sun. Hi have a couple of homes in sunny hot Arizona needing painted Sometimes water based paint is thinned anyway so I dont think it would cause early paint issues. Thank you so much for your time and expertise! I am recommending a primer above the current finish followed by new acrylic paint. Levels over 80% could stop the drying of the paint film altogether. The backer-rod needs to be slightly thicker than the expansion joint, example- a 3/4 inch joint needs 1 inch foam backer-rod. Appreciate any guidance that someone can give. Was scraping the efflor.. and behind that is the bare cmu. I scraped off all loose concrete and power washed it today. Polyurethane caulkings must be primed before painting, oil base primer. The primer just needs to dry overnight in most cases. We used to have a product called waterlox that filled the pours of concrete, waterproofed basements and came in colors. How would I go about this? We repaired an outside wall and are anxious to put the house back together before school starts as it is a bedroom. Sherwin-Williams makes a product called Loxon which we have used with great success. . LC, Hello! It also doesnt affect the wall. The exterior cinder block can be primed and painted after prep as normal, there shouldnt be any significant heat on the outside areas. Without mortar the top and bottom edges are exposed to water. This type of primer will soak into all the pores of the rough texture of the cinder block surface, sealing them so that the paint doesnt get absorbed into them. We live in South Louisiana what is the safe relative humidity for prime/painting cinder block walls. Will that work? Using the Dryloc isnt overkill but might not be necessary. This way you will be able to apply fewer layers of paint with a great result, and the result will also be a lot more durable and resistant. The Benjamin Moore Aura is very good paint and will hold up well, better than Sherwin Williams Emerald and most other top-of-line paints on the market today. I started prepping a concrete block wall that is part of a semi-finished stairwell outside my house that leads to an unfinished basement (the blocks are below ground). Sand added to the primer wont look like stucco. I just dont know what paint to by at Lowes. #5 I would apply a masonry stain (semi-transparent) and top coat or seal it with Seal Krete or something similar. Weve established that cinder blocks can be painted, and you can in fact use most types of paints with them without any issues whatsoever. The basement cinderblock is in good shape and it stays drybut does have a little efflorescence that Ill take care of during prep. Backrolling the 1st coat paint is also a good idea. Would you advise i prime the walls first before applying two coats final coats or can I just clean the prepare the walls then apply two quotes as per the specification. An alternative is house paint. Block fill doesnt stick well to previous coatings, like old oil based paint. Is a primer necessary? Make sure to rinse well if soaps are used. If the window installers used silicone caulking then I would have them fix it, if possible. Should I even attempt to spray a sealant or something underneath the deck, or just not worry about it? Sherwin Williams ProMar 200 or better. I dont know what kind of paint was used. Son has a house built in the 1960s. If a lot of water droplets form under the plastic then wait a bit. Will Zissner 123 primer and then a good acrylic paint cover the mildew stains and new mortar joints? Do I use semi gloss on cinder block walls? For other areas a standard acrylic primer, like Zinsser 123, will work well. We are using a Elastomeric paint made for masonry. Best to paint over all primers with in a week or so. The walls are dry. #1 Etching isnt needed. These blocks are very crumbly and leave concrete dust all over the interior of my vehicle. I assume it has lead paint, but it seems very intact. I want to make sure I understand the process for what steps I should take with regard to painting and sealing these indoor/garage foundation blocks Problem for another day! 100% acrylic. We have to reseal basement cinderblock. 3. Each block would need to be smooth in order to use a graining tool, unless you can free-hand paint wood grain. If there is persistent moisture you should use a water blocking sealer that can take hydrostatic pressure before painting. Do the stucco side first, I assume this is a building of some sort. Such as Watertite? Getting the pores sealed it very important with block walls. My plan after prepping is to wash the walls with non-rinse TSP, paint with Loxon and then finish with the exterior paint recently used to paint the rest of the house. If you have time, I do have another quick question. I poured what the sprayer pick up couldnt get to into the paint roller tray, then ended up dunking the intake tube into a bucket of water and proceeded to use the water to force the left over water in the spray hose out onto the wall. My concern is the longevity of the paint for the exterior wall. Does a new (porous) concrete block need etching? As a lot of people commented, thank you for you time. If we use a product like Rollerrock exterior concrete coating from Home Depot do we just apply to the cinderblock (we already powerwashed it) without needing to prime first? When Im given too much info, I often get overwhelmed and just lost. Then scrub the area with a wire brush. //www.enduracoat.net/Concrete-Sealers/b/2476102011. House was built in 1966. I am in the process of finishing my garage walls and inside garage foundation blocks. My mind tells me to do it before b/c its better for it to be adhered to the cement around the window instead of having it stuck again to paint, b/c paint is not as tough a surface as cement. Should I use a drylock or regular paint? I plan to use an epoxy primer, 50% solids that claims can be applied 8 mils thick. I dont think normal calculations for paint coverage apply due to the porosity in the block. The acrylic primers do a better job binding with any remaining chalkyness, do make sure to wash well and try to remove as much chalk as possible from the surface before priming. Lastly, I also use a spray bottle of water along with retarder to better help blend the paint colors.it feels like I should give the primer a few days to cure before I start painting on top of itWhat do you recommend? Original wood was all that super dark brown color from the 70s. Whats best to use especially with having to hang posters with tape on the wall in a few weeks? Overall this is the easiest to apply, easiest to maintain and cheapest way to go and have some color. Glidden really isnt that good. Is there something else I should be doing? Personally, I would use a 1/2 or maybe 3/4 inch roller. Back rolling is a great way to produce a better looking result even without the need for primer. It looks new and wonderful and we saved thousands of dollars doing it ourselves. Use acidic masonry cleaner to remove this unsightly mess. What is best to use on cinder block classroom walls? Is it safe to seal and paint if planning to add something on the top of this in a 1-2 years? It would be best to apply the texture (new stucco finish coat or ??) A 3/4 gallon per minute sprayer and a 517 spray tip is the minimum required. (As opposed to the glossy finish that paint has.) Are you referring to Acrylic Zinsser? The interior is easy. The stain will be soaked into the surface of the cinder block, to give it that permanent new color, but it will not affect the structural integrity of the cinder blocks in the slightest, so you can rest assured that no damage will be caused by staining your cinder blocks! My house was built in 1985 and the basement is unfinished with cinder block. Thank you for the great article! Thanks folks. Thanks again for your help. This isnt easy as cutting silicone caulking is all around hard, time consuming work. How long it will last depends on the quality of paint used, sheen and how much is used (1 or 2 coats). I was planning to buy SW Loxon Concrete Masonry Primer & Sealer and topcot with SW Resilience Exterior Acrylic Laytex paint. Interesting choice that will look good, as compared to regular paint. Lee. Moisture has entered the walls leaving stains as evidence, so I will redo the roof, and then move to walls. Now Im getting a little worried, b/c after I finish my block wall, I had plans to paint the rest of my house, and I hadnt thought /or planned on having to recaulk the rest of my windows. When it still leaked I called the waterproofer. Thanks again! Hello, and thanks for sharing this helpful info! The cinder block was painted white by the previous owner (no idea what he used) and could use a touch up after all of these years. Im wondering whether the sealer will hold up to cleaning, whether it will yellow from exposure, and how renewing it (if necessary) will look. There.s nothing wrong with the Valspar product. Should I prime it with block filler? We have had an ongoing water problem when it rains seems to be always on the west facing part of the building. The new paint should stick just fine. This would be a good idea if you add grout lines. With a good prime and paint, how long would the paint usually last before start to chip off and make the wall look ugly! Every paint store will have an exterior acrylic primer. Also, the previous water penetration has left some mildew stains and efflorescence. I have a recently constructed cmu shop and just finished aggressively pressure washing the interior walls for paint. Shinier paints are easier to clean but flat is fine if this is your preference. Oh, you dont have to back brush but you want to fill in the open pores of the block. 1 thing to add is maybe use an epoxy paint on the foundation block, contact your local paint store for availability and pricing. Yes, vacuuming is fine. Thank you again. Do I seal the interior or do I seal the exterior? One of your posts said polyurethane caulk needs to be primed. Either a block fill primer or no primer depending on your situation.