Walk through Fairmount on a July afternoon and the houses look postcard-perfect — deep porches, craftsman trim, mature pecans throwing shade over the sidewalk. What you cannot see from the street is what is happening inside those walls: nothing. No insulation. Original balloon-frame studs running floor to roofline with dead air between them and the Texas heat. An attic hatch that might as well be a vent. A pier-and-beam crawl space that nobody has touched since Eisenhower was president.

These homes were built for a different Fort Worth — no central air, no $180 TXU Energy bills, no July heat that sits above 100 degrees for ten days straight. The bones are excellent. The thermal envelope is something else entirely.

Why balloon-frame construction makes your problem different

Most spray foam work happens in post-1980 homes with platform framing: each floor is its own sealed box, and you insulate the attic and crawl space and call it done. Balloon framing — common through the 1940s in Ryan Place, Berkeley Place, and the streets around Forest Park — runs the wall studs continuously from the sill plate all the way to the roof. There are no floor plates blocking air movement inside the cavity.

What that means practically: a gap in your attic can pull outside air from your crawl space up through the wall cavity and into the living space. The building is breathing through its own walls.

This is why some older TCU-area homes have attics that look fine and houses that never cool down. The attic is not the problem. The framing system is.

Closed-cell spray foam bonds directly to the wood, fills the irregular gaps that batt insulation cannot reach, and creates an air barrier, not just a thermal rating. In a balloon-frame house, that difference is the whole ballgame.

The crawl space under your pier-and-beam foundation

Mistletoe Heights and most of the streets east of TCU sit on pier-and-beam construction. It is a practical design for Tarrant County’s expansive clay soils — the house can shift a little without cracking, and the foundation is accessible for repairs. That crawl space also connects your floor system directly to the outside.

In summer, humid outside air enters the crawl space, contacts cooler wood above it, and moisture builds. In winter, cold air undercuts the floor and your heating system works against a surface bleeding heat into the dirt below. Neither is doing your house any favors.

Spray foam on the underside of the floor joists, or on the interior crawl space walls if you are doing a full conditioned-crawl conversion, cuts off that pathway. Homeowners in the Near Southside and Fairmount area who have done this work describe floors that used to feel cold in December simply stopping.

For a crawl space encapsulation with spray foam in Tarrant County, plan on $3,000 to $6,500 depending on how large the space is and how accessible it is. If there is standing moisture or a compromised vapor barrier, that needs to be addressed before foam goes in — do not skip it.

What air sealing actually does to your TXU Energy bill

The billing math for a pre-1960 Fairmount or Mistletoe Heights home in summer is brutal. A 1,400 square foot bungalow with no wall insulation and a leaky attic can run $250 to $350 a month on TXU during July and August. That is not because the equipment is undersized. It is because conditioned air is escaping the building as fast as the system produces it.

The Department of Energy puts average savings from air sealing and insulation at 15 to 20 percent on heating and cooling. For a pre-1960 Fort Worth home with significant infiltration, you are starting from a worse baseline than average, so the actual improvement is often more.

If you are spending $3,000 a year on climate control, a 20 percent reduction is $600 back. A full attic and crawl space spray foam project on a 1,400 square foot house in Tarrant County runs roughly $4,500 to $8,000 installed, depending on conditions and access. Payback on energy savings alone is somewhere in the 7 to 13 year range. That calculation does not count comfort, and it does not count reduced HVAC strain.

The rooms that have been fighting you for years — the back bedroom that never cools, the bathroom floor cold every winter — tend to change faster than people expect.

The wall cavity question nobody wants to answer

The attic and crawl space are the right starting point. They are accessible, they are the highest-return moves, and they are not invasive. If the house still has comfort problems after that work is done, wall cavities are the next conversation — but it is a different project.

Accessing balloon-frame wall cavities without removing drywall or original siding requires drilling and injecting foam. Standard two-component spray foam expands with enough pressure to crack old plaster, so retrofit wall work uses a different product: injection foam, formulated to fill cavities without the expansion force. It is specialty work. Not every contractor offers it, and you should ask specifically what product is being used before anyone drills into a plaster wall in an older Fairmount home.

The other move that gets skipped too often: air sealing at penetrations. Older homes accumulate gaps around plumbing, electrical, and HVAC runs that add up to a meaningful infiltration load. Spray foam at these points is cheap compared to the benefit, and it is part of the same project if you are already in the attic or crawl space.

Tarrant County’s renovation market and your timeline

The older neighborhoods closest to Fort Worth’s urban core — Fairmount, Berkeley Place, Mistletoe Heights, streets around Forest Park — have seen steady renovation activity over the past several years. Buyers are purchasing pre-1960 homes and doing serious work on them.

Two things follow from that. Demand for spray foam contractors in these neighborhoods is real, and good contractors book out. More importantly: if your house is already in renovation and walls or ceilings are open, coordinate insulation before drywall goes back. You will not get that window again without tearing it out.

If the house is not under renovation, attic and crawl space work is accessible any time. Spring and fall are easier to schedule. The first sustained heat wave in June or July is when every Fairmount homeowner calls a contractor at the same time.

FAQ

Does spray foam damage old Fort Worth plaster walls?

Standard spray foam can, yes — it expands with enough force to crack plaster if injected without the right product and pressure controls. Injection foam is different: it is formulated for retrofit use in existing walls and does not expand the same way. If a contractor is proposing to drill into your plaster and inject standard two-component foam, ask exactly what product they are using. Plaster repair in a Mistletoe Heights home is not a trivial cost.

My pier-and-beam house already has a vapor barrier in the crawl space. Does that handle it?

The vapor barrier slows moisture from the soil. It does not stop air from moving in from outside. On a humid July morning in Fort Worth, outside air is still entering the crawl space around the perimeter and affecting the floor system above it. The vapor barrier and the foam are solving different problems. One does not replace the other.

Does TXU Energy offer rebates that cover spray foam?

Oncor’s residential rebate programs, which serve TXU Energy customers across Tarrant County, have historically covered insulation upgrades that meet R-value thresholds for Climate Zone 3. Spray foam installations that hit those thresholds have qualified in past program years. Rebate amounts and eligibility rules change annually. Verify current terms with Oncor before the project, not after — some programs require pre-approval.

How do I know if my 1940s home in Fairmount or Ryan Place uses balloon framing?

Go into the attic and look at where the exterior wall meets the roof structure. In platform framing, you will see a horizontal top plate capping the wall studs — the wall ends there. In balloon framing, the studs keep going past that point up toward the rafters, with no horizontal interruption. You can also check the crawl space: in a balloon-frame house, the studs often run continuously from the foundation sill all the way up. Most Fort Worth homes built before 1950 use balloon framing, but not all of them do.