Do Fieldstone Foundations Need to "Breathe"?

Debunking a Common Misconception and Explaining Why Interior Repointing Matters

If you own an older home in New England, there’s a good chance it has a fieldstone foundation — and if so, you've probably heard someone say, “You have to let it breathe!”

At NEFCR, we hear this phrase all the time from well-meaning homeowners, neighbors, or even contractors. But while the idea of a foundation "needing to breathe" may sound reasonable, it’s actually a common misconception that can lead to long-term issues if misunderstood.

In this post, we’ll break down where this idea comes from, why it’s misleading, and why interior repointing is usually the safest and smartest choice for maintaining a healthy, dry, and structurally sound fieldstone foundation.

Where the Myth Comes From

Historically, older homes with fieldstone foundations were built without modern waterproofing techniques. The stone and mortar joints were porous by nature, and the foundations were expected to take in and release moisture slowly over time.

So, when people say the foundation needs to "breathe," what they often mean is:➡️ “Don’t trap moisture inside the wall.”

And while that concern has some truth to it, here’s the important distinction:Letting your foundation "breathe" should never mean leaving cracks, gaps, or deteriorated mortar unaddressed.

Why the 'Breathing' Concept Can Be Dangerous

Leaving mortar joints open or deteriorated under the belief that it helps moisture escape can actually do more harm than good. Here’s why:

1. Moisture Doesn't Just Evaporate — It Comes In

Open joints or missing mortar invite groundwater, surface water, and humid air to seep in — especially in New England’s wet climate. This can lead to:

• Mold growth

• Musty odors

• Efflorescence (white, chalky deposits)

• Interior wall damage

• Increased humidity inside the home

  
  

  

  
  

2. Structural Risk Increases

As mortar crumbles and gaps widen, the structural integrity of the wall weakens. Over time, this can lead to shifting stones, bulging walls, or even partial collapses in severe cases.

3. It Becomes Harder to Control Moisture

With no barrier in place, your foundation can act like a sponge — drawing in moisture from the surrounding soil and creating an ideal environment for mold, wood rot, and insect activity.

Why Interior Repointing Is the Right Move For a Fieldstone Foundation

Interior repointing involves removing loose or damaged mortar from the inside of the foundation wall and replacing it with fresh, compatible mortar that strengthens and seals the joints.

Benefits of Interior Repointing:

• Seals out water while allowing controlled vapor movement

• Restores structural strength

• Improves air quality and reduces musty smells

• Prepares walls for waterproof coatings like Drylok

• Preserves the life of your foundation

It’s important to use the right mortar mix — typically lime-based — to ensure compatibility with older fieldstone and allow for natural movement and minimal vapor transmission.

Adding Mortar to Dry Stack Foundations

Some older homes in New England were built with dry stack fieldstone foundations — meaning the stones were laid without mortar at all. While this method was once common, it leaves the structure far more vulnerable to shifting, moisture intrusion, and long-term deterioration. Over time, gaps can widen, and without a bonding agent to hold the stones in place, the wall loses its structural integrity.

Adding mortar to a dry stack foundation through a careful interior repointing process can help stabilize the wall, reduce moisture infiltration, and extend the life of the foundation — all without compromising the historic character of the home. It’s a smart investment in both safety and preservation.

Does That Mean Exterior Work Isn’t Needed?

Not necessarily. In some cases, exterior drainage improvements or spot repointing may also be helpful. But in most homes we assess, interior repointing provides the greatest impact with the least disruption — especially when paired with waterproof coatings, dehumidifiers, or sump systems.

Final Thoughts: Let It Breathe... Responsibly

Your fieldstone foundation doesn’t need to “breathe” — it needs to function properly. That means having solid mortar joints, controlled moisture levels, and proactive maintenance. At NEFCR, we specialize in helping homeowners make the best decision for their unique foundation — not based on outdated myths, but on proven methods that protect your home for the long run.

Have a fieldstone foundation in need of some attention? Reach out to our team for a no-pressure assessment. We’ll walk you through your options and help you decide whether repointing is the right fit for your home.

📞 Contact us today — and remember: Done Right, Watertight.