Off Duty Heating and A/C · Bertram, TX · From the truck

Cooling a Pier-and-Beam House Near the Depot

Bertram has two kinds of houses, and we work on both most weeks. The newer ones at the edges of town have ducts in the attic and a system that came with the build. The older ones on the historic grid near the depot went up in the early 1900s, raised on piers, long before anybody expected a house to be cooled by anything but a porch and open windows.

Those older houses can be cooled well. They just do not take kindly to being treated like a subdivision house with extra birthdays. The walls are plaster or shiplap, and the floor sits over a crawlspace instead of a slab. Both of those change how air gets from the equipment to the rooms, and most of the bad installs we open up started with somebody ignoring that.

Built Before Anybody Planned for Air

A house from that era was designed to shed heat on its own. Tall ceilings, windows set across from each other, a raised floor with air moving underneath. None of it assumed a machine. So when central air shows up decades later, there is no chase for the ducts, no closet sized for an air handler, and no obvious spot for a return.

What most of these houses got first was window units. Then maybe a later owner added a system using whatever duct route was easiest that weekend. We find every layer imaginable. Sometimes the ducts are sound and just leaking. Sometimes they were run through the crawlspace in a way that works against the house every hour the system runs.

The first job is sorting out which one you have. A 1910 house on the original grid, a 1950s infill a block over, and a 1980s addition hung off the back of either one all behave differently, even under one roof. We read each part on its own before recommending anything.

What Lives Under the Floor

On a pier-and-beam house the crawlspace is where ductwork usually ends up, because it is the one place you can reach every room from without opening a wall. That works, but a crawlspace is outdoor air with a floor over it. In summer it is humid, and a supply duct carrying cold air through humid air sweats. If the insulation jacket is torn or squashed, water runs down the outside, soaks what insulation is left, and drips onto the dirt.

Give that a few seasons and you get sagging flex duct, runs crushed flat where somebody crawled over them, and joints that have quietly pulled apart. Animals find the gaps. On the return side, a leak down there pulls damp crawlspace air straight into the system and out of your registers, which is the last thing a house in Burnet County humidity needs.

Plaster and Shiplap Do Not Forgive Guessing

Getting a supply into an upstairs room, or a return into the middle of the house, usually means going through a wall or a ceiling. In a newer house that is drywall and a patch. In an old Bertram house it can be original plaster on lath, or shiplap the owners have worked hard to keep. Cut in the wrong place and you have damage nobody sells a matching piece for.

So the route gets planned before anything gets opened. Closets, the backs of built-ins, and floor registers fed from below are the usual friends. A floor register off the crawlspace often does the job with nothing touched above the floorboards. Where a wall truly has to open, we pick the spot with the homeowner and keep the cut as small as the fitting allows.

When Ductless Is the Better Answer

For a lot of these houses, a ductless system is the honest recommendation. A mini-split needs a small opening through an exterior wall for the refrigerant lines and the drain, and that is about it. No trunk line under the floor, no return grille to carve into plaster. Each indoor head cools the room it hangs in, and each room gets its own control.

That suits an old house. The bedroom at the far end that ducts never reached, a closed-in porch, an upstairs that bakes by midafternoon: each can get its own head. Where the existing ducts are in decent shape, a mix works well too, with the ducted system carrying the main rooms and a ductless head handling the one room that always lost the fight.

We are a Mitsubishi Diamond Contractor, so ductless is everyday work for us. We still do not push it on every house. If the crawlspace ducts can be repaired and they reach the rooms that matter, fixing them is often the simpler job. You hear both options and what each one gives up, and you decide.

The Window Units Left Clues

Most depot-area houses we walk into have a window unit history, and those windows tell us things. A room that needed its own unit for years is a room the central system probably never served. A patched framing opening under a sill, or an outlet added just for a unit, points to where the heat really sits in that house.

We also ask how the house actually gets lived in. Plenty of owners close off rooms in August or spend most of their time downstairs. Sizing one big system to cool every square foot at once, when half of it sits shut, gives you equipment that short-cycles and leaves the air damp. Older houses leak more air than new ones, which tempts people toward a bigger unit, and bigger works against you on moisture.

What We Check First on a Depot House

The crawlspace, flashlight in hand: duct condition, jackets, straps, joints, and whether the ground under the house stays wet. The return path, because an old house with one return and closed bedroom doors starves its back rooms. Where the air handler lives, and whether its condensate line drains somewhere sensible, since a clogged line dripping onto an old wood floor is a slow disaster. Which rooms had window units and why. Then the walls, so any route we suggest leaves the plaster and shiplap alone wherever it can.

Bertram is fifteen minutes up Highway 29 from our shop in Burnet, and our trucks pass through most days, so getting somebody under the house is an easy visit to set up. There is more on how we cover the town on the Bertram page.

Can you add central air to a house that never had it?

Usually, yes. The question is the route. If the crawlspace gives clean access to every room, a ducted system with floor registers can work well. If key rooms upstairs or at the ends of the house have no path without cutting plaster or shiplap, ductless or a mix of both tends to fit better. We look under the floor before recommending either one.

Why does my floor register blow barely cool air in summer?

On a raised house the cause is often right under your feet. A torn or missing insulation jacket, a joint that has come apart, or a crushed run in the crawlspace lets the cold air pick up heat before it reaches the room, or dumps it into the crawlspace outright. A look underneath usually finds it.

Will a mini-split look out of place in an old house?

The indoor heads are visible, so placement matters. We usually mount them high on an interior wall or above a doorway, where they sit quietly instead of becoming the centerpiece. The lines can run straight through the wall behind the head and down the outside. Floor-mounted and ceiling cassette styles are options in some rooms too.

Is a damp crawlspace a problem for the ducts?

It matters. Cold supply ducts sweat in humid air, and a leak on the return side pulls that damp air into the house. Well-sealed, fully jacketed ducts hold up far better. If the crawlspace is wet enough to show standing water, that is worth dealing with on its own before any new ductwork goes in.

Do you work on the later additions too?

Yes. An addition from a later decade often has its own framing, its own insulation, and sometimes its own small system or window unit. We treat it as its own part of the house, because it heats and cools differently from the original rooms it is attached to.