I have been in the process— oh, for about THREE years now!! — of parging the foundation walls of my home. Most new homes since the 60s and 70s have concrete block or poured concrete foundations. But waaaay back in the olden days (as when my house was built), foundations were built from field stones or cut stones. My home has cut stones. Over the 150 year span that my home has been standing, the field stones are still in excellent condition– it’s just the mortar that stinks.
Stone foundations have limestone mortar. It is water-permeable and over time and rodent-chewing (chipmunks are notorious for chewing away the mortar to build nests between the stones), the mortar begins to fail. In severe cases, this can cause foundation failure. In less severe cases (such as mine) this can mean a pocked, ugly appearance and some water leakage. Parging is the application of a thin coat of sticky cement over the wall surface. I’ve got about half of my interior basement done– what a job! My basement is huge and has 6′ high walls– and about 1/3 of the house’s exterior foundation wall (about 2 feet high).
The mix you use for parging must be special– it has to be sticky (that is, it must stick to a vertical surface without plopping down and off) and must remain stuck to the walls after it is dry. I had one dummy at Lowe’s tell me I needed mortar mix for the job, and me- being the dumb homeowner– listened to him and bought $200 worth of the stuff. Only to find that this is the WRONG stuff and crumbles off over time. :-p What you need to use is something call Sand Mix. It’s a combination of sand and portland cement. It should not crumble off if applied properly. There are even some acrylic additives you can add to the mix to make it even stickier- the additive is a lot like Elmer’s glue and comes in tall bottles. You pour it in to your Sand Mix mix. I didn’t use it. I’m too cheap (the additive is very pricey). I mixed up the Sand Mix and so far, it’s been working well. This is what I did about four years ago, and it’s holding up great:
To make the mix, you add water to the Sand Mix. You should only mix up as much Sand Mix as you are going to use in about 30 minutes. Otherwise, it will start to harden and won’t work anymore. Here’s what you will need for parging your walls:
- Sand Mix
- a bucket
- water (hose or watering can)
- spray bottle filled with water
- cement trowel
- cardboard or kneeling pad for your aching knees
It’s important to mix the Sand Mix *just right*– not too soupy or not too crusty. When mixed properly, you’ll be able to make M’s or S’s in the mix and they will stay in shape.
Before spreading on the stuff, make sure your wall is free from crud, like spiders’ webs, frass, and loose mortar. You will also want to dig down in the dirt a little, so that your parging line will not be seen should the soil shift around your foundation. I usually dig down about 3 to 6″, depending on the soil and the wall itself. Some folks go much deeper down.
Now, get your spray bottle and moisten the wall. This helps the parging mix to stick onto the wall. Don’t saturate your wall with loads of water– just get it wet.
Now lay your parging mix with your trowel, in 1/4″ to 1/2″ thickness.
Corners and around windows are the hardest, so take your time. Parging isn’t a difficult job, it’s just tedious. While parging, I found a few areas where moles and/or chipmunks had chipped mortar away. Grrr. I filled these holes in, to keep them out. Parging helps keep out water, too.
Click to enlarge any photo.
I am not too fussy about how smooth my mix goes on. Just laying on the mix is a 100% improvement!
Allow to dry for 36 hours before moving the soil back into your trench. The parging mix will change color as it dries, to a light gray. You can leave it this color, or paint it with some waterlocking paint, or exterior concrete paint. This job is so easy that you can even have the kids do it. You just have to make sure that they are consistent with the thickness and apply it so that everything is covered completely.
10. August 2011 at 8:52 am
Cody, you’re such the Internet professional, aren’t you? Slinging around advice from your chair when I don’t see anything that YOU have DONE, except sling complaints and criticisms.
I applied sand mix AS RECOMMENDED BY A PROFESSIONAL CONTRACTOR years ago. It’s still on my foundation and it still looks great. It hasn’t chipped or worn or faded. But the crappy mortar has literally peeled off the walls one year after I applied it. Mortar is a FILLER not a concrete adhesive!
The evidence rests.
10. August 2011 at 10:45 am
I want to clarify my own experience ( I posted about a year ago scroll up ) for some others in a similar dilemma. After reading Cody’s post I don’t want to get into a name-calling thing. But he obviously ‘strongly’ disagrees with the use of the Sand/Topping mix. He should be an expert based on his statement ‘you keep me in business’ so I don’t discount his post. Perhaps there is some reason people are not having success with mortar. I don’t know..
Here is my experience for what it is worth:
I found this site a year ago when I was searching everywhere for some good advice for my own parging challenge. The reason I tried this site is because it offered advice on exactly what I was doing. First … the word ‘parging’ is not used around here, even the contractors did not know what parging means. I didn’t either, but it was exactly the definition of what I wanted to do. They all mistakenly call it ‘stucco’ — which it is not.
So, after noticing a friend fail – using mortar – at the same job I was attempting with my foundation (cracking/flaking very soon after the project was finished) – I consulted the internet for help. But, first, I did try Lowes, …well, the guy at Lowes had good intentions but he wanted me to buy the exact same mortar for the job and do just like my friend had already attempted. I was not going to buy mortar mix and fail like my buddy (and mortar mix is not cheap for the surface area I had to do) … only to have to redo the job with something else. So I found this site and bought the sand/concrete/topping mix at lowes.
Ok, fast forward –
It has been an entire year since I used the topping concrete mix on my foundation, to parge…. and so far … so good. I must confess to some particular points (see below) to make this job a success. And I painted it with some Lowes premium paint designed for painting foundations/concrete/etc. It has some sort of elastic additive allowing it to fill and stretch. After a year – still looks good!
So,
Anyway, my point is this…. Cody may be right but there is obviously some method or technique needed to succeed in this project where the mortar-based parge will not flake or crack off. I feel like I had success but that there still must be an easier way. I can only speak from my limited experience. I did have success with the topping/sand/concrete premixed product from Lowes but the application was harder to apply than mortar. It was a bear to put on… it doesn’t want to stick. You must play with the consistency until you get a mashed potato product. Keep slapping the stuff on and it will start to stick. Wet the area first and make sure it is not painted – and it should untreated with anything making it slick or water resistant. It seems to stick or bond chemically when it draws moisture from the surrounding surface material. Patience is needed to put this stuff on. But, still it worked. I had large holes in the cinder-block and in the corners. I filled the large voids with the topping mix similar to how a automotive body repair shop fills with bondo.
In closing of my book here: I think that everyone’s goal here is to find a product that works without flaking or cracking. Like Cody said: the texture of the finished product is going to be rougher than with the mortar. So, this may or may not be a problem as you discover the texture upon application and see if it suits you or not. When I originally started to tackle the job I wanted to hire a professional. But he quoted me a price of $3.5k (another quoted me 4.1k) to do my entire foundation. This is why I decided to do it myself. It took me an entire weekend but only cost me about $400 … including the mix, paint, and paint supplies.
I am NOT a DIY’er … I HATE working on my house. And I would love to hire everything I need for keeping my home fixed up. But at 4k .. based on my own man-hours this guy was tripling my salary. This is why I chose to tackle DIY. I don’t like being robbed.
I would have paid 2k… just to not have to do it.
10. August 2011 at 10:56 am
Oh, not to hog the forums, but I forgot to mention that I received this comment (based on my parging choice) from a local professional concrete man. “As far as your foundation, I would not use mortar mix. It is not designed for patch work. Clean your surface well. At Lowes, get bonding agent and apply it before you patch with the sand mixture. This will help it to last longer and stay stronger….”
10. August 2011 at 11:04 am
Thanks, Edward, for sharing all that information!
10. August 2011 at 11:11 am
I didn’t realize the the original poster was a MRS. its all becoming very clear now. More power to you! I know how powerful a woman feels when she accomplishes something that usually only a man does. So powerful, they write books and post “how-to’s” on the internet of their great accomplishment.. Even if it is WRONG and looks TERRIBLE.
10. August 2011 at 11:14 am
HA HA, Cody. Maybe I shouldn’t also say that I’m black and Jewish, huh?
10. August 2011 at 11:33 am
Oh Cody – the most fun I have had all day was reading this site.
You can’t fight with kitty kat.
When they are wrong, you keep it shut.
When you want to watch the game … you compliment her and empty the dishwasher.
When you are right … you keep it shut.
..give it up..
here , watch this.
10. August 2011 at 11:53 am
Hey Edward… when we are right… looks like ya’all complain….
P.S. I can’t allow links to YouTube on this site…
P.S.S. Cody didn’t seem to have any problems insulting people BEFORE he found out I was a lady…
10. August 2011 at 11:57 am
To ALL THOSE WHO LEAVE COMMENTS:
Please be aware that this is NOT a forum or news site, it is my personal blog that I maintain at my own expense. I am under no obligation to allow any comments. Comments filled with expletives, insults, threats, or links to other sites not related to my blog will be deleted.
Thank you.
25. August 2011 at 1:34 am
Do you have any advice about what to do for a bowing or cracked stone wall? My house was built in 1940 and the basement is stone and mortar. The front wall of the basement has bowed in since I was a kid but a new crack has appeared in the corner recently and unsure if I should fill it since it looks like it is raising that corner of the house up. Unsure if I can repair or need to contact a professional. There are so many out there waterproofing basements only that it seems they really don’t know how to do anything else. I live in MO your basement is going to be wet! I just don’t want it to cave in. Any help would be appreciated. Thanks.
25. August 2011 at 2:01 pm
Hi Leah. My advice is to get professional advice. I’m not a mason. If it was my house, I’d get a mason contractor to see what’s going on. My house has old stones, and one corner has raised and cracked, too. My house still stands, but the bowing walls sound like a bad thing. Let me know what the contractor says!
9. September 2011 at 4:45 pm
Can you do this (parge)on the inside walls of the stone foundation or is this just for the outside foundation walls. I have field stones and the outside is already parged, but the inside has gaps that I can stick a fist into and the north wind blows through in the winter.
10. September 2011 at 10:19 am
Robin– I am doing it on the inside, too. I have seen other contractors do the same thing with their homes. The only thing is, MAKE SURE the existing mortar is in good condition before you parge. If you can feel air blowing through the holes, you need to do some foundation repair first.
2. October 2011 at 4:33 pm
first off nice d.i.y., now on to the basics …sand,cement,lime= mortar,used for binding bricks and blocks together,also used for parging, and or alias,aka.” plastering,rendering, stucco etc etc..most products purchased at home improvement store are just generic version of the prime good stuff bought and commercial contractor supply co., old day parging was lime stucco,” lime and sand”, year of 1824 portland cement was patented and used lightly… we can mix all types of things now from topping mixs for concrete repair, to parging mortars, its all in the mix ingredients and ratio’s to be determined accordinly for specified project,bonding agents have their place in the mix,and so do adhesive compounds etc, not to mention sealers,there are many important key steps that cant be missed,from preperation,hydration content,application method,mix ratio,additvies required,curing,sealing, miss one at will fail..@ Ed things cost money,and masonry restoration projects can become costly very quick, and usually done by experienced pros, factoring in estimated cost impacts, of material, total estimated time and labor,not to mention % for business overhead etc..take it from a pro, ive been a mason contractor for 25 years, not to mention carrying on a family tradition for over 150 years ,hope some of this info helps…..its not rocket science…its the skilled trade of masonry…there is a difference !!
13. November 2011 at 10:19 am
Thank you for your post. It was very informative. I have a 1929 craftsman home that has a similar foundation and similar issues. It was nice to see that I am on the right track.
18. November 2011 at 4:33 pm
Brystone good post. It is important to know WHAT the ‘stuff’ inside a bag labeled mortar or topping, or cement, etc. actually is! I just discovered that one brand of mortar product is different than another! I suppose there is no official “MORTAR RATIO STANDARDS REGULATION COMMITTEE” – unfortunately.
The ratio of sand, cement, lime, rocks, etc, are VERY very important.
Which reminds me … The story of a ratio fiasco:
I just made chili for a large group and gave my secret recipe to a friend (a friend who does not cook very often) – and they improvised in in trying to create my chili from their transcribed recipe.
But the result was that they ended up with a horrible tasting mess. While it still contained all the same ingredients .. the ratios were not the same at all. A cup of cumin is usually too much! Well .. at least for Texas chili …
25. November 2011 at 1:08 pm
This is all great information. My 146 year old home has a stone foundation and the exposed stone and mortar in the basement flakes. You can sweep the basement floor but in a few weeks the fine gritty powder is back covering everything in the basement. Is parging a solution for this problem? I don’t want to do something that will lead to foundation problems down the road. I know that these types of walls need to be able to “breath”. I’m willing to put in the time and labor but I’d like to know that I’m not doing anything that I’ll regret in the future. Thanks for any advice you can give.
25. November 2011 at 2:17 pm
Hi David. I’m no expert mason, just a home owner like you. After 100+ years, the limestone mortar does start to fall apart, especially if there is underground water (as is with my home). Also, chipmunks love to dig in the mortar and make nests.
If it was my foundation, I would brush out the loose mortar and repoint as much as possible with a similar type of mixture (lime). Then, I would parge with sand mix. That’s my two cents and that’s what I have heard most masons recommend. Of course, if you live in an area with a high water table, you may need to waterproof the exterior foundation wall.
25. November 2011 at 3:23 pm
Thank you for the great advice. Luckily since resolving a clogged drainage pipe outside we haven’t had much in the way a moisture in the basement so the waterproofing shouldn’t be necessary.
25. November 2011 at 8:05 pm
if masonry cement you buy get O, or at most N. and i would in the hardest “type N high bond” to parge. preferably high lime custom mix.
and cut out any joint you are to repoint at least twice the width in depth. as well to a solid back, and dampen before pointing.
cheers.
28. November 2011 at 10:44 am
Cody, yer an idiot so STFU!
30. November 2011 at 4:41 pm
Thank you Joel. I think this is going to be a project for me in the new year when the weather outside is, as they say, frightful. I’ll be reasonably warm in my basement parging away.
22. December 2011 at 3:09 pm
did put the mortar mix on the trowel and sort of smudge upwards to stick the parging I’m not sure how to apply it so it sticks on the wall, trying todo the inside of the basement to. Cool article!