Why We’re Fixing Our Stone Foundation with Hydraulic Lime Mortar

We dropped the ball this past summer when it came to fixing up the exterior stone foundation and our front porch. In fact we kicked that ball far, far away.

But progress has just been made!

In case you’re just now even aware that we have a front porch…

…last year the status of our porch was that the stone pillars holding the porch up were crumbling. You could realistically have pushed the stone pillars over with one hand.

There was a time crunch with Winter coming, so last Fall we did a temporary fix with cement blocks (and we’ve kept the original stones for when we do redo the pillars) and replaced the very rotted wood beams underneath until we could take the time to put in new porch footings and piers.

It’s very Redneck right now. I apologize for the awful.

We’ve had the “repointing” of our stone foundation that’s under the porch also high on the “front porch repair” list.

Repointing means restoring the mortar that holds together stone or brick masonry. As you can see, a scary amount of the mortar is missing in our wall under the porch.

Since the porch is now opened up, we wanted to take advantage of this opportunity to repoint the foundation in that area, especially as it was the worst of our four walls.

Karl and I are DIYers in restoring our home’s original integrity, but we don’t mess around when it comes to structural projects and (gladly) give it to the pros.

But not just ANY masonry pros (of course).

Nope. By dumb luck, we knew we had to find ARTISANS or we could risk the structural integrity of our home.

Here’s a little story of how we came to know what we needed with dumb luck:

Several years ago I was in a newly renovated historic stone barn that was being used as a farm-to-table restaurant. I noticed a man who was observing the stone work and overheard him comment about how cement or your typical on-the-market mortars are the worst thing possible for old stone walls (and brick made before the 1950’s) because it causes structural harm. He said that he hoped they had been done correctly with lime mortar, as many times people do not even know the damage they are doing to such buildings when they do not use original materials for repairs.

I’m a research junkie, so out of curiosity I looked into it a bit and found the man had been right.

Actually, like many construction materials of the time that our home was built, lime mortar is much more “smart” and we really ought to be using it more in our buildings even today. I found it quite fascinating when I learned that lime based mortars have been used for thousands of years; only in the recent 20th century has cement become pervasive for masonry.

Lime mortar has not gone away and become obsolete in the U.S.; it’s more that people do not know about it or how to work with it.

When our home’s foundation was built they used lime mortar for setting the stone, and it’s not just because it was what was readily available at the time. The beauty of lime mortar is that it allows the stones to “breathe” and “flex”.

Bricks of the 19th century through to even the 1950’s are more porous than today’s bricks. Stones are naturally porous as well.

Lime mortar has the amazing ability to keep the structural integrity of your brick or stone walls because it is also porous. It sounds counter-intuitive as we’re always told to make our homes impermeable these days (lending sometimes to mold problems in newer homes). However, when rain wets the stones/brick and lime mortar, the water is able to leech back out through the mortar, evaporate, and keep the masonry from having corrosive water damage over time.

With concrete-based mortar, the water is trapped and instead leeches back out through the stone/brick, corroding and wearing them down, and thus also the structural integrity.

They were rather clever back then when it comes to construction materials that work hand-in-hand with one another; it’s important not to mess up that balance.

Also add in the benefit that lime mortar will last you another 100 years, versus cement-based which might last you 20.

Therefore, this is why I was looking for someone who specialized in restoring old stone and brick walls with lime. It took some time to find someone, but find them I did.

Our repointing restoration master was Ken. He is so knowledgeable and is truly passionate about old buildings and respecting the artisans who have come before.

In fact, this is a quote from Ken:

Such a legacy.

It’s been a privilege to find someone that truly loves old buildings as much as we do and works to properly restore them.

Can I just say…another thing that I love about craftsmen who specialize in old buildings – it’s a craft. These people are those who are true artists and take pride in their work. You can see it all the time in the details and workmanship of old buildings, and it’s so neat to find it in people today because it is increasingly sparse.

I didn’t get to take any pictures of the process because it all took place under our cramped front porch, but I found this very helpful video of a man using the same process to repair a wall.

By the way, any one else find it really satisfying watching construction project videos? I could watch a real-time video of just someone painting a room or making a brick wall…

Anywho, I do have a good “after” picture.

Ken also mentioned that in the middle of our foundation they found a small spot of some original old bricks as part of the wall instead of stone. They fixed those up, then found some matching stone under the porch and covered up the bricks with them. We’re all not sure why the bricks in that one area. As far as we know there’s always been a front porch on this house, so no possible need of a window or old coal chute being covered up…

Ideas?

It’s nice to know we won’t have critters finding holes and crevices to sneak in through, let alone water for longer than we’ll even be on this earth.

Here’s to another 100 years!

 

Hi! Got questions? Ask away in the comment section below! :)