What Happens When You Don't Use the Right Mortar

It's a real problem in Chicago. Very few contractors who do masonry work on old buildings use the right kind of mortar for the job. Whenever you need to repoint or replace the mortar on your historic brick building, you should have a sample of the original mortar analyzed so that you can create a mortar with the same components. If you don't, all sorts of horrors can happen.

When we tore down the gypsum ceiling boards in our basement last summer, we exposed about 85 years of efflorescence on the interior wall. When moisture travels through the brick, it carries water soluble salts along with it, which end up evaporating on the surface. Ours wasn't too bad, a bit thicker in some spots than others, but overall probably acceptable for such a length of time. I used a shop vac to clean up most of it, and our basement walls looked like this:

Well, after a long winter and an even longer, damp spring, there seems to be a fair amount of efflorescence collecting in a single spot above one of the front windows.

That's a lot to collect in less than a year. Most of our basement after 85 years didn't have this much. So we went around to the front of the house to take a look at what was going on. What you're looking at here is some really cheap patch work done on the exact opposite side of this wall; we found tubes of Quikrete in the basement, and we think this is what the previous owner used when they said The Box House had been recently tuckpointed.

Whatever they used, the result is that the building is not breathing properly in this spot. The bricks are not able to expand and contract as they're supposed to against the rigid mortar, and moisture is somehow being forced through the brick.

There are earlier repairs to the brick as well; we're not sure when these were done--our guess is maybe 40 years ago when the last owner bought the place--but it looks like a better attempt was made to mach the mortar to the original at that time. At any rate, there are no problems to the brick where these earlier repairs were made. However, it is beginning to crack in certain spots--nowhere near as much as the most recent mortar repairs are cracking--but enough that we'll have to address it soon.

But here's the real problem, and thank goodness it's on the garage and not the main house.

On this entire corner, the PO used Quikrete or some kind of rigid cement to patch the mortar. The mortar does not move at all. So as the bricks here are expanding and contracting, they are literally crumbling against the mortar. If we let it go long enough, we'll have this web of mortar and no bricks. We're going to attempt, very soon, to repair and remortar this ourselves as a way to practice for the bigger task of repointing the house.

Most masonry contractors, when they tell you they can match the mortar, mean they'll match the color. Period. By not using the proper materials, or trying to work with a buildings original materials, such contractors are literally destroying the face of the city. Ever since we learned about the importance of the right mortar at a recent masonry workshop, we've noticed building after building across Chicago crumbling away. It's very sad.

Do you know what's also sad? The fact that the dang squirrels cannot wait until September for our neighbors apples to ripen; instead, they've been leaving half-eaten apples all around our yard. They usually take a bite or two, toss it over their shoulders, and grab another one.

Messy little buggers.

Historic Masonry Seminar -- Repair, Remediation, Cleaning

Eight o'clock in the morning is probably not "early" for most of you; but if you are an independent contractor who is used to getting up at noon and going to bed at five a.m., it's pretty freaking early. Still, Ted and I managed to drag ourselves up in time to attend a free morning seminar at the Garfield Park Conservatory called "The Care and Maintenance of Your Historic Masonry Home," hosted by the Historic Chicago Bungalow Association and Neighborhood Housing Services of Chicago. It was well worth the effort.

I'll post the class description here, because they do have another workshop coming up in April.

From greystones to bungalows, Chicago residential neighborhoods are defined by brick and stone buildings. However, many homeowners are uncertain of how to best preserve, maintain, and repair their historic masonry homes. Presented by Mario Machnicki, president and founder of Marion Restoration, this workshop will cover: common conditions and deterioration problems, identifying priority repairs, establishing a scope of work for masonry repair projects, best practices for cleaning and tuckpointing, and financial resources to fund rehab projects. With over 30 years of experience, Mr. Machnicki has been featured in This Old House and The Chicago Tribue.

Next seminar:
Saturday, April 25, 10 a.m. to 12:30 p.m.
Avalon Public Library
8148 South Stony Island Avenue
Chicago, IL 60617
RSVP to greystone@nhschicago.org, or Blanch at 773-522-4637

We learned a great deal about masonry in general, and Chicago building practices in particular, during the two-hour presentation, which was followed up by a Q&A where they welcomed specific questions about your own building. It covered the types of building materials commonly used, such as limestone, sandstone, and brick, and the types of mortar and style of mortar joints. It also provided links to some excellent online preservation briefs, including:

Assessing Cleaning and Water-Repellent Treatments for Historic Masonry Buildings

Repointing Mortar Joints in Historic Masonry Buildings

Dangers of Abrasive Cleaning to Historic Buildings

There are nearly fifty briefs in all, on a wide number of topics, so check it out.

The key to preserving a building all comes down to one thing: the mortar. (Well, two things, the other is keeping out water.) To ensure that The Box House will last another eighty years, we should be repairing our masonry with like materials, and get our mortar matched exactly. We kind of knew that already--although, amazingly, most contractors do not seem to--we just needed more direction in how to go about mixing new mortar and where to get our mortar analyzed. There is a company called U.S. Heritage Group, Inc. that can run a chemical analysis on our mortar and give us the exact composition.

A previous owner repaired some of our mortar joints with Quikrete--we found the empty tubes in the basement. This product, like many modern mortars and cements, is rigid and doesn't breathe. Areas of our brick garage have a layer of cement smeared on the surface, which now prevents it from breathing. It's probably only been a few years since these bungles were performed, but we're already seeing issues related to these bad repairs--spalling, cracking, efflorescence. If we don't remediate them, over time the brick--which can no longer expand with weather variances--will completely break and crumble against the inflexible mortar.

Other things we learned which are directly applicable to our building:

The paint on the walls of our brick basement can only be removed chemically. It is a tedious process, but he recommended three products to try: Soy Gel, Prosoco, and Dietrich. Under no circumstances should we use mechanical means. What surprised the two of us is that sandblasting is actually illegal in Chicago. Not that we would try it, the historic brick is too soft, but it's illegal because of the lead dust the paint might contain, which will coat the neighborhood. We were shocked because we had just read an article in the Tribune about a couple who had renovated their basement by sandblasting the walls. It seems to be a common practice; I guess contractors either don't know about it or assume they won't get caught.

I neglected to ask specifically if we could use those same chemicals on the limestone outside, which still has its coating of paint because I haven't decided exactly how I'm going to remove it. We've been simply watching it flake off and "helping" it along.

However, Machnicki did mention that these same companies sell detergents to clean exterior masonry; the trick is to soak your masonry first so that the chemicals don't soak in, and to rinse it thoroughly with water. He mentioned a 900 psi as being okay, but he also strongly cautioned testing areas when cleaning first. Yellow brick, for example, is extremely susceptible to damage, and he's seen brick that has been bleached out from improper cleaning. We have some green biological growth on our portico, and he recommended trying water first.

Someone else asked about finishing off a brick foundation basement, and we were told that the furring strips should be placed an inch away from the walls to allow the masonry to continue to breathe.

Another person asked about insulation, but we were told our buildings didn't need it. With walls a foot thick, it wasn't necessary. He did mention insulating plaster, but we didn't get the chance to pursue the topic. I'm not certain what that means.

All in all, it was a very enjoyable morning--definitely worth getting up at the ungodly hour of eight.

Plus, we got to spend some time at the Garfield Park Conservatory, which just celebrated its one hundredth birthday.

Don't let this picture fool you; it's still pretty chilly in Chicago.

Removing Paint from Concrete, Masonry, Limestone

I have a hard time sitting still without getting antsy. I think it's because I work for myself, so time spent not working on a project is time spent not making any money. When I'm not on the computer, I feel I should still be doing something somewhat useful and not just sitting around and relaxing. Ted's much the same way.

A few days ago, when the weather was in the sixties, I whined until I got Mom and Ted to sit with me on the front steps to enjoy a cup of coffee and watch the world go by. The picture below was taken in winter, but that's pretty much what the front entrance looks like now, just without snow.

But did any of us sit still? No. I'm pacing back and forth in front of the house, coffee in hand, discussing plans for the garden with Mom. Ted was sitting on the porch in the shade, but in between sips of coffee he's working on this:

Scraping off flaky white paint. (What's the matter with us? Why can't we just relax?)

The previous owners had coated everything they could in white paint prior to selling. The interior walls had a fresh coat and I think the same paint--interior paint--was used to paint over all of the decorative masonry on the exterior. If you look at the top photo, you can see that all of the window sills and all of the horizontal trim has been painted white.

You can tell better in this photo (from the original listing):

So those little squares at the top, those long horizontal decorative bits that wrap around the house, and every window sill has been painted white.

Only, I'm pretty sure it's the same interior paint used on the walls. The flat surfaces are mostly peeling and flaking, and I don't recall them doing that last fall when we first saw the place. Winter was harsh on them. It's very easy to get the paint off these surfaces with a scraper, and as Ted removed the paint, we saw that the surfaces are actually dirty, and in some spots there is green algae, or whatever it is that grows on limestone. So the paint doesn't have a firm grip. At least not on the horizontals.

Ted made some decent progress that day, and every nice day we've had since I've been out there with my cup of coffee. I have most of the flat surfaces by the front steps now clear of paint. But I still have the vertical surfaces to do, and I'm encountering quite a bit of trouble. The stuff is not flaking nearly as much, and in some parts, it's quite stubborn. I'm afraid of scraping too hard.

I was hoping not to have to go the chemical route, but I think a trip to Sherwin Williams or Home Depot might be in order. I had tried a soy-based paint remover on some of the interior brickwork, but without success. Although I've heard a few good things about PeelAway 7 and its use on masonry, I haven't personally encountered anyone who has tried it for such. I tried PeelAway 6 on some woodwork with mixed success--it's okay on latex, but has problems with enamel. Is there really that big a difference between the 6 & 7? I haven't been able to locate the PA7 locally, and it's pretty expensive online, so I'd like to know more about it before making the investment.

So, does anyone have a recommendation for removing paint on masonry? Have you been able to remove paint from similar surfaces?

Update: My apologies to Dynochick; I originally called all of the decorative trim concrete, when it fact some if not all is probably limestone. I was not aware of just how different the care of both materials are, and carelessly mixed terms. Sorry that my post led you astray.

Before heading out to the paint store for PeelAway7, I decided to check for some coupons online and found one on another blog for 20% off at Sherwin Williams. I'll give it a try this week. Hope it's a valid one.