The Cross House

Tuckpointing a Historic Chimney. HELP!

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The great north facade of the Cross House. See the chimney? It’s brick. It’s tall. It’s fabulous. Now, see how the chimney is bisected by the big cornice?

 

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This is what the chimney looks like just under the cornice. This is sooooooo not good. There should be mortar between the bricks!

 

At some point somebody thought it would be a good idea to paint the red brick…red. So, you are looking at red paint rather than red brick.

Sigh.

As a reader of Old House Journal since the 1970s (yes, I really am that old), I have known for decades the dangers of repointing, even though until today I never had a practical use for such knowledge. You see, most masons will just buy the type mortar they always use and fill in all the empty spaces.

THIS IS BAD.

Because, old brick is rather a different thing than post-WWII brick, in that it is much softer. But modern mortar is very hard. This is fine with modern brick, but will prove a disaster with old old old brick. Like my 122-year-old brick. Mortar which is too hard will literally destroy the brick. Mortar should be just a bit softer than the brick itself.

The problem for me is:

  1. What kind of mortar do I need?
  2. Where the hell do I buy it?

I found this online:

Mortar comes is types. Type M, S, N, O, K, and L.

Type M is the strongest and hardest and contains the highest percentage of Portland Cement while Type L has no Portland Cement and is the softest.

Type O and Type K are recommended for most historic masonry applications. However, most masons are not aware of this.

So, it would seem that I would be good with Type O or K, right?

Right?

HELP!!!!!!!!

 

 

16 Responses to Tuckpointing a Historic Chimney. HELP!

  1. I don’t know if the answer is set in cement, so to speak. My ca.1900 Victorian house has hard bricks and hard mortar. I found that off the shelf mortar mix worked well here. You may want to research at your local historic society. They may have information that may help you. For instance, a local prolific brick factory that produced ‘X’ quality bricks. Or anectodal evidence of the quality of brick work in the area. And perhaps the owner of other (your architect here) houses in your area may know. If that doesn’t help, I seem to recall there was an OHJ article on the subject. If you don’t have it or can’t find it (or other sources) online, call the Old House Journal. They may help you and maybe they will be interested in your story. Buona Fortuna, Michael Bazikos

  2. There were different degrees of hardness in brick. In 1988 I was in your situation. My house was built in 1902 and the 4 chimneys needed repointing just as yours does. Having read an article in Old House Journal concerning using new mortar with old brick, I had the mason add lime to the mortar mix to soften it up. He added too much lime — creating a much too soft mortar. Now in 2016, I have to do it all over again. My bricks are as hard as today’s brick. I noticed the square edges of your brick. From here, they also look like the hard brick. Beware of using too soft mortar. In 30 years someone will have to do it again. An experienced mason should be able to guide you in the right direction.

  3. The New York rowhouse manual has a recommended recipe on Page 17 for a soft mortar including both lime and Portland cement “to repoint most Nineteenth-Century rowhouse facades.” I’ve also heard some people say that mortar for historic masonry should include no Portland cement at all, but on the other hand if the brick is hard enough to handle some, it will hold up longer especially on a chimney. I’d be afraid to make this call.

    I’m terrified of everything about dealing with my own facade, too. The houses on my street with “restored” original brick fronts appear to have had the durable outer layer of the brick power washed off and were scrub pointed with white mortar. Meaning they have false thick mortar joints applied over the brick in the style of a 1950’s tract house when the original joints were about 1/8″ wide and colored red.

    I’m planning on getting recommendations for a mason from the Historical Commission even though my house is not landmarked. Some of my brick is water damaged and shedding red dust onto the sidewalk, but fixing it this year is not in the cards.

  4. Ross, in addition to my wooden pile, I own a massive 1905 brick–it followed me home and I had to keep it– that has chimneys similarly afflicted to yours. Check out this company.

    They look like a wonderful resource–claim to analyze composition and even match pigment in the mortar if your mortar was originally tinted, as is likely. Could you lift off a brick or so from the top and get an original sample of the mortar to send to them?

    As to how long a subscriber to OHJ–I’m a charter subscriber, you spring chicken, you!

  5. We’ve done five chimneys now (thank god, that’s all of them!) and have made our masons use K mortar with additional lime and sand added to further soften it, as well as a ton of red pigment (that stuff wants to be pink very badly, you’ll need a lot more of it then you think you do). Your bricks do look like the harder type (flatter, squarer edges), but it’s impossible to tell from a photo obviously. When it comes to the house bits at eye level we plan on using the lime works already recommended to you in the comments, since they’ll match the aggregate as well. Last I spoke to them they’ll also fabricate pointing tools if you have unusually tooled joints. Compared to some of what you do, this will be a cake walk (a very dusty, very heavy, cake walk)…

  6. I discovered your blog about a week ago and have become obsessed with the Cross House and your progress on its renovation. I have binge read all blog posts over the past few days, I even dreamt about Victorian wallpapers and woodwork last night. My co-workers asked yesterday if I would be making a road trip to Emporia – it is THAT bad, my coworkers have noticed my obsession! If I lived closer, I would load up my sewing supplies and be on my way to help with curtains, or my guess would be, show you how to accomplish making them fit.

    Your blog is a joy, your writing manner a delight, I look forward to following along on this journey. Thank you for the view you have given us into your life and your amazing house.

    • I just wrote a similar comment on a previous article (about restoring Ross) about binge-reading and fascination. And I did not say but I also dreamt I talked to Ross in the Cross house and he took me to a tour of it. obsession. !:-D

  7. We have this problem in Chicago. Inexperienced masons simply use hard Portland mortar on our soft common brick. Aargh.

    Good luck. I vote for a little softer mortar just to be safe.

  8. I know Kansas has a rich history of brick making and that bricks are a well researched area of interest for collectors and historians. I bet you can ultimately learn the source of your bricks and their composition! Just for fun, check this article.

  9. There is a fellow in Independence Iowa that does historical brickwork. I cannot remember his name since I met him in the early ’90s but he redid the horrendous repairs on the Frank Lloyd Wright house near there.http://www.friendsofcedarrock.org/ You might be able to get his name and contact information from this site. He could help with figuring out what to do.

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