Repointing, And What I've Learned

11/28/2020

Let's get this outta the way first: if you're not startin' your days off with a 3+ mile hike through the woods with 2 dogs, you're missin' out. There are lessons to be learned (or, at least reminded of) and fun to be had.

Roscoe, the elder statesman of the two, he's been on literally 1,000s of hikes and park excursions in his nearly 12 years of life, so it's all old news to him. He doesn't move as fast or nimbly as he once did, but he still gets the job done and he still enjoys doing it.

Freckles, who is 14 months old, she's learning how to navigate things without being leashed. She's done pretty well with it so far, although I have to be selective with where we go and what times we go there. She REALLY enjoys the hikes.

Taking the 2 out on hikes (or, "adventures") is very much like the real life version of the story of the tortoise and the hare. Roscoe moves at a solid, steady clip. He won't dazzle anybody with athleticism or daredevil shenanigans, but he's reliable, calm, and seems to always think of a way to overcome (go around, really) any obstacle he encounters. Freckles would sprint everywhere she goes if I let her, and she really likes being the frontrunner. She's not very big and doesn't always make great choices, but she ATTACKS life with a ridiculous level of fearlessness and excitement.

When it comes to the basement repointing effort, inspiration can be drawn from both dogs.

On the one hand, there's, like, 8 million stones that have to get repointed. If I think about it in those terms, it gets a little overwhelming and I have to remind myself that if I tackle the work in small, manageable chunks - slow and steady wins the race, right? - I'll eventually have it all knocked out.

On the other hand, because I can overthink just about anything to death, when I encounter a masonry situation I'm not real familiar with or know how to handle, I do my best to NOT think about it too much and, instead, just get after it. The hare didn't win the race, but it probably didn't get too hung up on any trivial details in its pursuit of victory.

I am not a mason, nor have I ever really done any repointing work. The exterior brick needs it pretty badly in several spots and rather than learn on the outside of the house, where all the world can see my work (and mistakes), I figured I'd cut my repointing teeth in the basement, where a few sections of wall could stand to be redone and if any of it turned out horribly, not too many people will ever see it.

So, what have I learned in the early stages of my basement repointing effort?

There is a lot of contradictory information on the internet (go figure, right?)
Preparation is critical
Patience if critical
Timing is everything

CONTRADICTORY INFORMATION

Before I started repointing anything, I watched about 3 dozen YouTube videos where I saw about 3 dozen different repointing methods employed, each one claiming to be the "right" way to repoint stone. Awesome.

Which mortar does one use? Type N? Type S? Type O? Type M? The differences between the mortar types boil down to their ratio of cement to lime to sand. In theory, different mortars are good in different situations, but for example, a lot of people will disagree about when and where to use Type N vs. Type S. In my case, I chose Type N; it's a good general purpose mortar and because my foundation stone is limestone, Type S's compressive strength is a little steep.

Am I supposed to prep the stone with a little water before slapping in the mortar, or do I apply the mortar to completely dry stone? I hit the cleaned out joints with a couple shots of water from a squirt bottle. Sure, it adds a miniscule amount of water to the mortar and potentially causes it to cure to a marginally lower strength than if I hadn't introduced the water, but the water 1, knocks down the dust on the stone, allowing the mortar to adhere to the stone better than if the stone were dry, and 2, it works as a bit of a lubricant, enabling me to really push the mortar waaaay back into the deeper spots I can't reasonably get to with any tools.

What tool(s) do I use to apply the mortar? A trowel? A jointer? A spoon? The palm of my hand? 99% of the time, I use a grout bag and a couple small jointers. Occasionally I may use a trowel to smooth out a mortar surface, or maybe apply the mortar by picking some up with the trowel and sliding it into a joint with one of the jointers, but mostly it's grout bag and jointer(s).

PREPARATION

In my book, prep is just about as challenging as getting mortar back into the joints and looking good, but it's way more work and way less fun. However, there isn't any sense in trying to rake out perfectly good, rock-solid mortar, so if I hit a patch that doesn't want to budge, I leave it as is. For the mortar that's in bad shape, which is most of the original stuff - and some of it has legit turned to dust due to water infiltration - I use this thing, a chipping hammer that's intended to be used for knocking slag off of welds:

It works surprisingly well and is kinda like having 2 tools in 1, and the more tools I can wield with each hand the better. I use the pick end to beat on the old mortar and loosen it up, and I use the chisel-like end as sort of a scraper, running it through all the joints to really chew up the old mortar. For any little nooks and crannies this hammer is too big to get into, I use a crappy old flat blade screwdriver to clean things up. Then I shop vac the joints and suck up as many little crumbs and dust as I can.

What's really important is cleaning out the joints as deeply as I can; this obviously allows me to get more mortar in the joint and make for a stronger end result than if I only cleaned out the joints to a shallow depth. Likewise, having a really deep, cleaned out joint allows me to have a little room to work with the jointers and the more room I have to work, the better the end result looks. Plus, the more stone I can apply fresh mortar to, the stronger the wall becomes.

PATIENCE

Shaping the fresh mortar once it's between the stones so that it looks decent is sort of an art. It doesn't seem like it'd be all that difficult, but there is a razor thin line between the amount of pressure required to flatten or shape the mortar without having it move in all sortsa unintended directions and the amount of pressure that will make the mortar an unsightly, swampy mess.

It can be frustrating work. Sometimes the stones' shapes don't allow for ideal jointer angles, or multi-directional tooling options. Sometimes I can get a spot flat and smooth, but in the process I pulled too much mortar out of the joint. Sometimes I feel like I'm about to apply the perfectly light amount of pressure for a final pass, only to pull a Lennie-and-his-puppy and totally demolish what I'd just worked really hard to get lookin' good. Sometimes I have 8-10 joints going, and I can't seem to get any of them lookin' right and I kinda feel crying wouldn't be inappropriate.

But patience - not my strength, if you know me in real life - is critical. The mortar will slowly start to cure and stiffen up a bit, it'll become easier to work with, and the joints will end up lookin' pretty decent. That is, as long as I take a deep breath, clear my head, focus on 1 joint at a time, get it as good as I can get it, and come back to it again a few minutes later if I'm not happy with it.

TIMING

In my book, timing is everything when it comes to applying mortar to the stone joints and shaping it, and probably the thing that's most difficult to discern from all the YouTube videos out there. There is an optimal amount of time to let mortar sit in a joint before working it. There is an optimal amount of time to let a worked mortar joint sit before coming back to work it again. There is an optimal amount of time to let a final version mortar joint set up before hitting it with a brush to smooth everything out and clean off all the mortar boogers. And, there is an optimal time to let everything cure before using a little water to clean up any mortar slurry on the stone faces. Of course, this all varies depending on the depth of the mortar joints and how much mortar is being dealt with, but doing everything without waiting a little bit between steps, or waiting too long...bad news.

Timing is critical. Once I had that figured out, the work became a whole lot easier.

I still struggle with it sometimes, and I dunno that it's the kind of work that's ideally suited for an OCD perfectionist, but I definitely like seeing the end result.