Crumbling Foundations

A QUICK HISTORY LESSON

Fieldstone foundations are just that; foundations made from stones gathered in the fields, at one point usually surrounding the home itself. The builder of the home, which may have been the original farmer himself, would have dug the hole for the foundations by hand. Initially, he tried to dig the dirt forms nice and straight, but they kept falling in on him. So, he decided to dig them on an angle. This will come back to haunt him later. Next, he begins laying the stones at the bottom of his foundation. At the turn of the century mortar mix was expensive. Often, these older foundations were constructed entirely of clay soil; lacking any kind or footing or base. As time goes on, he begins to notice that every time it rains water penetrates the basement. This is because he dug those walls on an angle. Now he has loose soil outside the walls of his foundation: with the original hard packed soil sloped like a swimming pool: directly towards and into his basement. As the water enters through the soil in between the stones, it brings the clay and sediment with it.

Crops come in, livestock is sold and he can now afford to either replace the clay in between the stones with proper mortar or cover over the wall with concrete mix and pour himself a concrete floor. Time goes by and eventually water from the exterior begins to degrade the concrete and/or the mortar in between the stones, causing mud to enter through the stones yet again. He pours a concrete ledge all around the bottom of the wall to prevent the mud from coming through. Fast forward a century or so and find yourself standing in your basement with your Crocs and socks on; (no one’s looking, we won’t tell)! Water is still coming up through the floor and the concrete parging is steadily falling off the interior of the fieldstone walls.

THAT’S WHERE WE COME IN

Natural Hydraulic Lime or NHL

We’ve done hundreds of century home restorations through over the decades. Our founder, John MacRae, lives in a century home himself. There are several approaches to solving your problem, from historical restoration (using only stone found on site and natural hydraulic lime mortar as opposed to modern day Portland mixes), to full envelope waterproofing details using the latest techniques and materials. Natural hydraulic lime mortar, or N.H.L as it’s referred to in the trade, is used not just to match existing mortar (for a historically accurate restoration), but also for its elastic properties. If areas of the mortar need to be replaced on the interior basement walls and the foundation has either a weak footing or no footing at all, N.H.L is used. Even after 100 years, the wall may shift a little whereby N.H.L will accommodate this. Modern Portland mixes are very hard and unforgiving which can cause the fieldstone or the rubble blocks in between the mortar to crack and disintegrate. Using the wrong materials (leading to improperly tuck pointed walls), can cause the structural integrity of the foundation to fail in 10 years (instead of lasting another 100+).

If the wall requires the installation of a footing or is already on a solid footing than Portland can be used on the exterior of the wall in conjunction with modern waterproofing methods. By making sure that no water is entering from the exterior, we can now begin work on the interior.

See exterior waterproofing, the process.

How the interior is finished depends on your future vision of the space. If you’re content with the basement being a little bit musty, then tidying up the walls by repairing the mortar joints and ensuring that there is no water coming up through the floor is the most prudent course of action. If you’re looking to make the basement more useful and you want to eliminate the majority of that musty smell, then a whole different approach is taken.

WHAT IS MASONRY WHITE WASHING?

White washing is a cement based coating used to seal the interior foundation walls while actually brightening the ambiance of the basement. Another benefit to whitewashing is that it preserves the mortar allowing the fieldstone foundation to last even longer. Many masons, historians and foundation repair companies go back and forth about white washing. Our founder John MacRae isn’t a fan while his son Gavin is more open to the process; both live in century homes. Talking with other foundation repair specialists as well as other masons and suppliers, fieldstone foundations that have had white washing applied tend to need much less work over time. Combine whitewashing with the right drainage system coupled with a sealed basement floor, and you can leave the Crocs upstairs and just go with socks! You can eliminate a large percentage of the musty smell associated with field stone foundations and bring the basement into the 21st century!

WHERE OLD MEETS NEW

Living in a century home is not for the faint of heart. A little knowledge goes a long way to achieving peace of mind. The use of older technologies and building materials is not always a bad thing, it’s knowing when to go old-school and when to mix the old with the new. There is a reason your old home is still standing – it was built to last. With the right care, materials and techniques your century home can stand indefinitely.