Tall Crawlspaces, Taller Problems: Understanding Masonry Pier Loads
In central North Carolina—especially in booming areas like Raleigh and Wake County—getting your foundation right isn’t just a good idea; it’s absolutely critical. One of those hidden challenges that often slips under the radar is the use of tall masonry piers in crawlspaces, a solution frequently employed on steep lots. At first glance, these piers might seem perfectly normal, but as with most things in construction, the devil is in the details.
Tall masonry piers come into play when a crawlspace foundation wall must be built higher to accommodate a sloping lot. The problem here? Weight. Engineers design footings to distribute your home’s load across the soil, but tall piers—especially those built from cinder blocks stacked nine feet tall and filled with mortar—can be surprisingly heavy. How heavy is a nine-foot-tall masonry pier? It tips the scales at over 1,800 lbs on its own.
Here’s an example with some simple math. Let’s make some assumptions:
Soil Capacity: Each square foot of soil can support 2,000 lbs.
Footing Size: A footing that measures 2' x 2' covers 4 square feet.
Load Calculation: Imagine the home exerts 7,000 lbs of load onto a pier and the pier itself weighs 500 lbs. That’s a total of 7,500 lbs. With 4 square feet of soil—each square foot able to support 2,000 lbs— the footing can support 8,000 lbs. No problem! We have 500 lbs of soil capacity left to spare.
But if that pier weighs 1,800 lbs instead 500 lbs, the total load jumps to 8,800 lbs, exceeding the soil’s capacity by 800 lbs. This overload can cause the pier to settle, and because it’s so tall, it might tilt or rotate. It’s a bit like stacking a tower of blocks too high on a soft cushion—the whole thing starts to lean and wobble.
This issue is often overlooked. When inspecting a tall crawlspace, it’s crucial to review the building plans and ensure that the engineer has accounted for the extra weight of these piers. Otherwise, your footings might be undersized, setting the stage for long-term foundation problems.
Understanding soil bearing capacity and proper masonry design isn’t just academic—it’s essential for building a stable, long-lasting home. For homeowners and buyers in central North Carolina, this knowledge helps you ask the right questions and protect your investment.
Tall crawlspaces are common in Apex, Holly Springs, Wake Forest, Wendell, Zebulon, and Rolesville. While you’ll find them throughout the Triangle, they’re especially prevalent in these particular areas surrounding Raleigh and Cary.
Want to know what to watch for in tall crawlspaces? Check out Part 1 and Part 2 of my blog series, where I break down the key details of their construction.
At Kurtz Residential, we’re committed to uncovering these often-overlooked details during our inspections. If you’re planning a pre-drywall inspection or need a home inspector for your next home, we’d love to help—book a service with us today!
