Pennsylvania has the fourth-oldest housing stock in the country. The median home here was built in 1965, a quarter of them predate 1940, and in cities like Reading and Scranton it is more than half. That is not trivia — it decides what floor you can actually put down.
Four things an old Pennsylvania house does to a floor
1. There may be no plywood down there
Houses built before the 1950s often sit on 1×6 boards laid diagonally across the joists rather
than on sheet subfloor. That is a perfectly good assembly — it is what the original hardwood was
nailed to, and it is still doing its job a century later. What it is not is flat and continuous, and
most modern floors want flat and continuous.
Practically: solid hardwood is happy on it, provided the new boards run across the planks rather
than parallel to them. Floating floors, thin engineered products and glue-down all want an
underlayment or a plywood overlay first, and that is a real line item, not an upsell.
2. The 9×9 tile in the basement
Nine-inch square floor tile laid between roughly 1940 and 1980 very often contains asbestos, and
so does the black cutback adhesive underneath it. Twelve-inch tile from the same era can too.
Undisturbed, it is generally not considered a hazard, and the accepted approach is usually to
leave it in place and cover it rather than to tear it out. What creates exposure is breaking,
grinding or sanding it. This is not a demo-day decision to make on the spot — see our page on
9×9 tile and asbestos in Pennsylvania homes.
3. Old joists move
Century-old floor framing deflects more than today’s code allows. Wood floors flex with it
happily. Rigid materials do not: this is what cracks a tile or stone installation two winters after
it was laid, and the tile is almost never the reason.
If tile or stone is on the table in an older house, deflection needs measuring before anyone
picks a product, and an uncoupling membrane needs to be in the quote.
4. The boards may already be worth saving
Narrow-strip oak was the Pennsylvania standard for decades, and wall-to-wall carpet was the
standard on top of it for decades after. There is a genuine chance the best floor in your house is
already in your house. Refinishing typically costs about a third of replacing, and it is the
original floor rather than an imitation of one.
The order to do this in
- Look under the carpet first. Thirty seconds with a pair of pliers at a closet
edge tells you whether this is a refinishing job or a replacement job, and those have very different
budgets. - Pull a floor vent. The cut edge gives you a free cross-section of the flooring
and the subfloor: board thickness, whether it is strip or engineered, and what it is sitting on. - Find out what is in the basement. If there is 9×9 tile, know that before you
plan any grinding or levelling. - Then choose a material. Not before. The subfloor narrows the list more than
your taste does.
Frequently asked questions
Is a plank subfloor a problem?
Not in itself — it is the original construction and it is usually sound. It is a problem
specifically for floors that need a flat continuous surface, which is most floating and glue-down
products. Budget for an underlayment or a plywood overlay if you are going that route.
How do I know if my joists are strong enough for tile?
Deflection is calculated from joist size, spacing and span, and it is worth having someone
measure rather than guess. The rule of thumb the trade uses is L/360 for ceramic and L/720 for
natural stone — an older house frequently fails the second one without work.
Can I level an old floor before installing?
Yes, and self-levelling compound or a plywood overlay are the usual methods. The one thing not to
do is grind down high spots in a floor that might have asbestos tile or cutback adhesive anywhere
near it.