First and foremost, you can not use concrete / portland cement in any masonry work on a house built before 1850, and maybe even until 1900. It’s worth asking a local mason to see what sort of bricks you have in your home. If they are new bricks and fired to be very hard, cement with confidence. However, older bricks, usually those with inclusions like small stones, have been hand-fired and therefore should only be pointed with lime-based mortar.
It has taken years to build up the courage to face our basement wall. Years of sweeping up dust and bits of stone as the wall sheds. Years of research on how to make quicklime into lime putty and what ratio of lime putty to mix with sand to form the appropriate mortar for a row house built in 1832. Meanwhile, steadily voicing concerns that we were one rock away from the house falling apart around us. Finally, my husband said, “Make a plan already!” and so I did. I’m currently in the middle of earning my Master’s in project management which means I can’t write as often as I’d like to. It also means that any project I undertake is a good time to practice the project management skills I’m learning. So last month, I spent an entire Sunday researching lime mortar, again, and writing out a plan which included a list of materials needed, a work breakdown structure, and a timeline with actual real dates on it.
Download our repointing project plan.
The most challenging aspect of the project was the mortar itself. Quicklime is very caustic and corrosive. Turning quicklime into lime putty is time consuming, messy work; not something you would want to do in your kitchen. I was overjoyed to discover Ecologic natural hydraulic lime from Limeworks. Ecologic mortar is the perfect choice for older buildings that need lime mortar but it has the ease of modern mortar because you just add water. We used a ratio of three pints of water to 12 pints of Ecologic to obtain the perfect consistency. After trying to use several things to stir the mortar, we discovered that using our hands worked best. Mix for a good five minutes and definitely double up on the gloves since the lime is very drying. Also, use a face mask because the dust is irritating. Once it’s mixed, you don’t need the mask but keep the gloves on throughout the project. Mixing the mortar is very therapeutic and like building a sandcastle at the beach and we made small batches as we worked across the wall.
We’re lucky to live nearby one of Limeworks retailers, Killian Hardware in Chestnut Hill, Philadelphia, Pa. Killian’s is a fantastic place that carries many products for the older home. It’s hard to estimate how much mortar you’ll need for a stone wall since it’s irregular but we used four and a half bags. Ecologic is around $26 per bag and each bag covered about four-square feet worth of pointing.
Repointing is messy work and you’re going to want to make sure the area is sectioned off with plastic, along with the floor.
Before we got started with the mortar, we cleaned out as much old mortar and debris as we could. For an interior wall, about an inch depth is recommended. Our wall had been shedding for so long that we only had to suck the loose sand out with the shop vac and give the rocks a good scrubbing with a stiff-bristled broom-head. We had no idea but there are a few very large pieces of quartz in our wall; one the size of a cantaloupe!
In terms of pointing, we had purchased trowels but discovered that using our hands was really the best method. Again, it’s going to be rough on your hands, as the lime is very drying, but our fingers could get the mortar in the crevices most effectively. The trowels were a bit expensive and using our hands saved us $30. We also didn’t need the wood or dowels for the palettes either, knocking another $6 off, making the overall budget for the project less than $200. The best method for applying the mortar was to take small lumps and work it into the joints slowly, like creating pottery. There is something very zen about working with your hands and really considering the shapes of the rocks and how to work the mortar around them.
Overall, it took the two of us about 10 hours to repoint a 10′ by 12′ wall, including a lunch break and the two hours I worked by myself while my husband went back to Killian’s to get more mortar because we needed five bags instead of the two we originally purchased. The next day we devoted to clean up and a light spray of the wall in the morning, followed by one more spray before bedtime. It’s important to note that you do want to use the mortar during the more humid times of the year, so spring and summer. Lime mortar needs to dry slowly. Our basement is usually about 70 percent humidity which is excellent for the wall. When cured, the mortar should last a nice long time and not damage the stones and bricks like portland cement.
A final note; Ecologic comes in several color options and there are kits to further customize the color. We used the DGM 50 color because we wanted a nice contrast with the rocks and were doing the entire wall. You can send a sample of your mortar to Limeworks and they will help create a mortar that matches the color if you need to repoint in sections.
We didn’t realize before the project but the repointed wall, with the brighter mortar, is much more welcoming than it was before. In a basement dining room/kitchen it’s very important to keep things light and cheerful to avoid the feeling you’re in a dungeon. We can also expect fewer drafts and less dust.
Row House Living 
Thank you, thank you, thank you! Had I not run across this article, I would have for sure used the wrong thing. Very much appreciated!
Great read, and a job well done! Keep on restoring and thanks for the shoutout!
What would happen if you used cement mixed with lime as mortar? My “old” mason did that …. he is at least 68 years old .. Thanks
Hi Vih – Thanks for your comment! Portland cement has a different hardness than lime mortar. I’m not sure what mixing the two does but if the result is too hard for the historic bricks, there’ll be damage. Do you know how old your bricks are? If they’re from after 1900, you might be OK. With my own house, the facade was done with cement and it’s taken a toll on the bricks. Sad really. A competent mason should know the difference. ~ S
Great job, your photos and details were really helpful to get my mind around such a project. About how long did it take before the mortar hardened?
Hi Christopher – Thanks for your comment! It was fairly hard by the next day, so overnight. It took a few weeks for it to look really dried out but that’s supposed to happen – the longer it fully dries the better it takes. When a facade gets repointed, the masons will typically wrap the house in burlap so the moisture reduces at a slow rate. So we let it take it’s time. That’s said, we had the room back together the next day and the wall just sort of did its thing – S
Hi! I used this blog to work up the courage to repoint my own stone wall with Limeworks as well. Did you use anything to seal the wall when you were done?
Hi Jackie! Congrats on your project! We did not seal our wall, or any in our house. It’s important to maintain the ability for the wall to breathe. Generally-speaking, for masonry, you want the moisture to be able to escape and a sealant might prevent this. The good news is that, although you end up having to touch up your mortar every decade or so, Limeworks makes it really easy. It’s been a few years now and the wall is holding up nicely.
Does the wall still shed with the new mortar?
Yeah, a little bit, although we’re five years now and it’s pretty good still and the basement gets damp which doesn’t help. It’s supposed to be sacrificial and after a few years you’ll need to touch up. I’ve been following projects going on at Colonial Williamsburg and I believe they said you can expect to get 15-20 years from soft mortar. LimeWorks, my favorite easy mortar, has lots of information on their website as well.
How can you tell if you have lime mortar? I’m in the Graduate Hospital neighborhood, and I’d guess our house is 1890s. The stones in your rubble basement wall look similar to ours, but I think ours are schist (lots of sparkle in them). Did your basement have a dirt floor or was it already concreted by the time you lived there? So many questions… Thank you!
Hi Sara! To find out what your mortar is made of definitively requires a test. But if your house was built before 1875, chances are it has lime mortar. Quite a few houses in Philly have the famous Wissahickon Schist, ours too! Your house, being around 1890’ish, I know the ones over there pretty good, might still have lime mortar even thought it’s a little later. Does it seem to be shedding? Lime mortar does that. If you rub at it, it’ll come off. Our kitchen is actually in the basement, which is not unusual in the small older homes in QV and SH, so it’s always been finished. I actually think it gives a smaller home a better layout; my house being small but still has a proper dining room in which I can seat six comfortably, eight if we get really cozy. I may think differently when we have to replace the fridge though. Under the floor, I believe, is concrete, but at some point, someone put radiant heating in there which makes me think it was entirely redone during a big reno in the mid 1970s. If I ever pull up the tiles, it’ll be neat to see what’s under there.
Thank you! I’ll look into getting it tested. Lots of mortar has fallen out, and the stones are shedding, too. Lots of bad repairs were done on the upper floors, which makes me wonder if there are basement wall patches done with concrete. Further investigation to be done! Thanks again – I bookmarked your post a few years ago and find it very helpful.
Which color of mortar did you use?
Thank you.
Hi Mary. I forget the actual color but we matched it to the existing mortar. It’s a warm cream color – not stark white, a few shades from the lightest color offered.