Basement Concrete Floors in Pittsburgh: What May Be Hiding Under Your Finished Basement
One of the things that makes Pittsburgh neighborhoods so distinctive is the age and character of the housing stock. According to the U.S. Census Bureau’s American Community Survey, nearly 30% of Pittsburgh’s housing units were built in 1939 or earlier, with another substantial portion dating to the middle of the 20th century.[1]
You can see that history throughout the region. Pittsburgh’s own architectural surveys document homes dating to the 19th and early 20th centuries in neighborhoods including Troy Hill, Spring Hill–City View & Spring Garden.[2] Lawrenceville also experienced substantial residential development during the late 1800s & early 1900s.[3]
Here in Sewickley, that architectural history is still an important part of the community. The Borough maintains three designated historic districts and a Historic Review Commission charged with helping preserve their historic character.[4]
Those older houses weren’t necessarily built with today’s idea of a finished basement in mind. Spaces that homeowners now turn into family rooms, home gyms, offices and entertaining areas may have originally served much more utilitarian purposes. And the concrete floor beneath one of those basements may have a history of its own.
Older basement slabs can vary considerably in thickness, condition and how they were installed. Some have also accumulated decades of patches, leveling compounds, flooring and renovations that make it difficult to know what’s actually underneath until the finished materials come up.
That doesn’t mean an old basement floor automatically needs to be replaced. Plenty of older concrete remains perfectly serviceable. But if you’re renovating an older Pittsburgh-area basement, it’s worth understanding the condition of the slab before you invest in everything that’s going on top of it.
What We Found in Our Own Sewickley-Area Basement
When we bought our house, the basement was already finished, complete with wall-to-wall pink carpet. Once we removed the carpet, we discovered that the original concrete floor underneath was noticeably uneven.
At the time, replacing the concrete wasn't part of the plan. We used concrete leveler to create a suitable surface and installed a wood floor over the existing slab.
And for about ten years, that worked.
Sometimes the Problem Under a Basement Floor Stays Hidden for Years
For about a decade, the basement floor served us well. Eventually, though, the wood flooring itself began to fail. Years of heat from the wood-burning stove contributed to warping, and then a failed water tank leaked into the basement and caused additional damage. At that point, we knew the wood floor needed to come out.
What we didn't know yet was that replacing the finished flooring would lead to a much larger concrete project.
What We Found Under the Basement Floor
Once the wood flooring was removed, Ben began investigating the original concrete more closely. That's when we realized just how thin the existing basement floor actually was. In areas, the slab was only approximately two inches thick. Even more concerning was its condition. When Ben struck one area with a mallet, the concrete essentially disintegrated into dust.
At that point, adding more leveling material and installing another finished floor over the existing concrete didn't make sense for our project. Instead of continuing to build on top of a badly deteriorated slab, we decided to remove it and address the basement floor itself.
Why Do Older Pittsburgh Basement Floors Deteriorate?
Every basement is different, and an old concrete floor isn't automatically a bad concrete floor. But there are plenty of reasons an older slab may no longer be a good candidate for simply covering with another flooring material.
The condition can be influenced by the original concrete and installation, slab thickness, the base beneath it, decades of moisture exposure, drainage conditions, settlement and previous repairs or modifications. That's also why cracks alone don't necessarily mean a basement floor needs to be replaced.
A few stable cracks in an otherwise sound slab are very different from concrete that is extensively uneven, crumbling, shifting or deteriorated. Before deciding between repair and replacement, it helps to look at the condition of the entire floor—and what you ultimately want to do with the basement.
We Wanted More Basement Headroom
Replacing our concrete floor solved another problem we'd been thinking about.
Like many older basements, ours didn't have particularly generous ceiling height. The basement had a drop ceiling, and we had considered removing it and installing drywall to gain some additional headroom.
Once the old concrete floor had to come out anyway, we realized there was another possibility. Instead of gaining all of the additional space from above, we tackled it from below. We were able to excavate farther down, lower the elevation of the basement floor and gain additional headroom before preparing the space for the replacement concrete. For our house, what started as a flooring replacement ultimately became an opportunity to improve the basement itself.
Can You Lower a Basement Floor to Gain Ceiling Height?
Potentially—but this is one area where the details of the house matter tremendously.
Excavating a basement isn't simply a matter of removing concrete and digging deeper. The depth and configuration of the existing foundation and footings have to be considered, along with soil conditions, drainage, plumbing, moisture management and the intended finished floor elevation.
Digging below the existing foundation can require significantly more complex structural work, such as underpinning. Local permit and code requirements may also apply. In our basement, the existing conditions allowed the project to accomplish what we wanted, but that doesn't mean lowering the floor is appropriate—or straightforward—in every home. If you're considering it, the first step should be understanding what's supporting the house before deciding what's coming out underneath it.
Preparing for a New Basement Concrete Floor
Once an old slab is removed, there's an opportunity to address the floor from the bottom up. The exact preparation depends on the house and project, but it can include excavation and grading, preparation and compaction of the base, stone, moisture-management measures, reinforcement, drainage or plumbing work, and preparation for the new concrete.
This is also why replacing an old basement floor can make sense to coordinate with a larger basement renovation. If plumbing, drainage or other work needs to happen below the floor, it's much easier to plan for it before the new slab is poured.
Why We Chose Stamped Concrete for the Finished Basement Floor
After living with carpet and then wood flooring in the basement, we decided to do something different the third time around. Instead of pouring a new concrete slab and then covering it with another flooring product, we made the concrete itself the finished floor.
We chose stamped concrete, which allowed us to get the appearance we wanted while eliminating a separate layer of finished flooring over the slab.
For a basement that had already experienced water damage, that was particularly appealing to us.
Stamped concrete isn't the only option for a basement floor. Depending on the intended use of the space, homeowners may choose a traditional concrete finish or another finish designed for the way the basement will be used. But for ours, stamped concrete gave us the combination of durability and appearance we wanted.
Repair or Replace an Existing Basement Concrete Floor?
Our basement was an extreme example. Discovering concrete that was only about two inches thick in areas and deteriorated enough to crumble when struck made our decision relatively straightforward. Many basement floors aren't that dramatic.
Depending on the condition of the existing slab and the plans for the space, repairing cracks or damaged areas may be entirely appropriate. In other cases, replacement may provide an opportunity to address underlying conditions rather than repeatedly repairing the surface.
A basement concrete floor may be worth taking a closer look at if you notice:
Concrete that powders, flakes or crumbles
Significant or recurring cracks
Uneven, sunken or shifting areas
Previous patches or leveling products that continue to fail
Moisture or drainage concerns
An unusually thin slab exposed during renovation
Plans for plumbing or drainage work beneath the existing floor
A deteriorated slab you're preparing to cover with expensive new finished flooring
The key is determining why the floor is failing before deciding how to fix it.
Planning a Basement Renovation in an Older Pittsburgh Home?
One lesson from our own basement is that what's underneath the finished floor matters just as much as what you eventually put on top of it.
Our basement went from pink carpet, to a leveled original slab with laminate flooring, to discovering badly deteriorated concrete roughly a decade later. Removing that old slab ultimately allowed us not only to replace the concrete, but also to gain additional headroom and rethink what we wanted from the finished floor. Today, the stamped concrete isn't something hiding underneath the basement. It is the basement floor.
If you're dealing with a deteriorating basement floor or planning a larger basement renovation, Ritter Concrete can take a look at the existing concrete and help you understand what you're working with. Sometimes a repair may be all that's needed. When the existing floor needs to come out, we can handle the removal, preparation and installation of the new concrete floor.
Areas We Serve
Ritter Concrete provides basement concrete removal and replacement in Sewickley, Bell Acres, Edgeworth, Sewickley Heights, Leet Township, Franklin Park, Ohio Township, Moon Township, Wexford, Warrendale and Cranberry Township, as well as surrounding communities north and west of Pittsburgh.
Don't see your community listed? Contact us to see if your project falls within our service area.
Sources
[1] U.S. Census Bureau, American Community Survey, Physical Housing Characteristics for Occupied Housing Units – Pittsburgh city, Pennsylvania. U.S. Census Bureau – Pittsburgh Housing Data
[2] City of Pittsburgh, Department of City Planning, architectural survey materials documenting historic housing in Troy Hill, Spring Hill–City View and Spring Garden. City of Pittsburgh Architectural Survey
[3] City of Pittsburgh, Department of City Planning, Lawrenceville Historic District documentation. Lawrenceville Historic District Documentation
[4] Borough of Sewickley, Historic Review Commission. Sewickley Borough – Historic Review Commission
