Chimney Chases on New Fishtown and Northern Liberties Infill Homes
New River Wards construction vents differently from the old rowhomes. Here is what a framed chimney chase is, how it fails, and why an airtight new home can still have draft problems.
What a chimney chase actually is
Drive through Fishtown or Northern Liberties and you will see them everywhere now, the tall, narrow boxes rising off the roofs of the new infill homes that have filled in the cleared lots and former industrial sites. Many of them are not masonry chimneys at all. They are chimney chases, framed structures wrapped in siding that enclose a metal flue liner or the venting for a modern appliance, and they do the same job a brick stack does without being built the same way. On a new build, a chase is a sensible, common choice, lighter and cheaper to build than a full masonry chimney, and perfectly safe when it is done right.
Because a chase is framed and clad rather than built of brick and clay, it fails in different ways than an old rowhome stack, and it has to be inspected with that difference in mind. The metal liner inside, the chase cover that caps the top, the flashing where the chase meets the roof, and the appliance connection at the bottom are the parts that matter, and a crew used to reading a hundred-year-old masonry flue has to switch frames entirely to read a chase honestly. Treating one like the other is exactly how a less experienced outfit gets a new build wrong.
Where a chase goes wrong
The most common chase problem is water, and it usually starts at the top. The chase cover, the metal lid that closes off the top of the chase around the flue, is what keeps rain out of the framed structure, and a cover that is the wrong size, poorly sealed, or has begun to rust lets water into the chase where it can rot the framing and corrode the liner out of sight. The flashing where the chase passes through the roof is the other common entry point, and like any roof penetration it depends on being installed and maintained correctly. Neither problem shows from inside the house until the damage is well along.
Inside, the metal liner is the part that does the safety work, and on a newer build it is generally in good shape, but it still has to be the right size for the appliance and properly connected and sealed. We check the liner, the cover, the flashing, and the connection on a chase inspection, because a chase that looks fine from the street can still be taking on water at the top or venting poorly at the bottom. The point of inspecting a new chimney is not to assume it is fine because it is new, it is to confirm it.
- A rusted or ill-fitting chase cover lets water in
- Failed roof-line flashing is a common entry point
- Hidden water rots framing and corrodes the liner
- The metal liner must be sized and sealed correctly
- A new chase still needs to be inspected, not assumed sound
Why an airtight new home can still backdraft
Here is the part that surprises new homeowners most. A brand-new, well-built Fishtown house can have worse draft problems than a drafty old rowhome, and the reason is the very thing that makes it efficient. Modern construction is airtight and tightly insulated, which is excellent for the heating bill, but a flue needs makeup air to draw. A fire or an appliance pulls air up the flue to carry the exhaust out, and that air has to come from somewhere. In a leaky old house it seeps in around windows and doors without anyone noticing. In a sealed new house, there may not be enough getting in, and a starved flue drafts weakly, backdrafts, or fills the room with smoke and odor.
When a new homeowner calls about a fireplace that smokes or an appliance that smells, the problem is often not the chimney at all, it is the air the house is giving it. The fixes range from a dedicated makeup-air supply to adjusting how the home is operated, and the right one depends on the house. The important thing is to diagnose it correctly rather than chasing the chimney for a problem the building envelope is causing. A crew that knows the new River Wards builds knows to look at the air before it looks at the flue.
Getting a new build's chimney right from the start
The best time to understand a new home's chimney is before a problem appears. If you have bought or built an infill home in Fishtown or Northern Liberties, an inspection confirms the chase cover, the flashing, the liner, and the appliance connection are all sound, and it gives you a baseline you can come back to. If you are already fighting a draft or a smell, an honest diagnosis sorts out whether the issue is the chase, the liner, or the makeup air the airtight house is failing to provide, so the fix actually solves the problem.
A new chimney is not a chimney you can ignore, it is just a chimney that fails differently and needs a crew that reads new construction as fluently as it reads old masonry. The River Wards have both kinds of housing on the same block, and the right answer for a framed chase on a two-year-old build is nothing like the right answer for a coal flue down the street. Knowing the difference is the whole job.
One more thing worth understanding about a chase is that, unlike a solid masonry stack, its weak points are mostly accessible and inexpensive to maintain once you know to look at them. A chase cover can be resealed or replaced before it rusts through, the roof-line flashing can be checked and corrected like any other roof penetration, and the liner and connection can be inspected on the same visit. None of that is major work when it is caught early, which is the whole argument for a baseline inspection on a new build. The owners who run into real trouble with a chase are almost always the ones who assumed that because the house was new, the chimney would take care of itself, and let a small, fixable cover or flashing problem quietly soak the framing for years.
Whether your River Wards home is brand new or a century old, the chimney deserves an honest, documented look from a crew that knows both. If you have a draft problem on a new build or just want to confirm the chase is sound, call 215-602-7626 and we will come take a look.
When you want it handled, call 215-602-7626 and we will get you on the calendar.