After a Brooklyn Renovation: Why Your Dryer Vent Probably Needs Help (Even If You Just Spent $400K)

We are Vent Pro NYC, a Brooklyn-based dryer vent crew. Half of our calls in any given quarter come from one of two places: someone whose dryer just stopped drying, and someone who just finished a renovation and noticed something feels off. The second category is the one we want to talk about, because it is the one where the customer is almost always surprised.

The pitch we hear most often: the customer just finished a four-month gut renovation in Bed-Stuy or Park Slope. The kitchen is gorgeous. The new washer-dryer is a stacked Miele or an LG WashTower in a custom-built laundry closet that did not exist five months ago. The GC handed over the keys, the punch list is closed, and the customer pulls a wet load out of the new dryer and feels heat radiating off the side of the machine like a pizza oven. The lint trap is empty. The drum spins. Something is wrong.

It almost always comes back to the duct. We have walked into post-renovation jobs where the contractor reused a fifty-year-old galvanized run packed with old lint. We have opened drywall to find a brand-new flexible foil duct routed through a stud bay with a 90-degree kink in the middle. We have pulled apart soffits in Crown Heights to find a vent termination pointing at the inside of a soffit cover, dumping moist lint-laden air into a brand-new ceiling cavity for six weeks. We have measured airflow at 38 FPM at the back of a dryer that should read 1,200 FPM minimum.

This piece is the long answer to a question we get every Monday morning: my contractor said the vent is fine, do I really need someone to look at it? Short version: yes. Long version follows.

Why a Brooklyn renovation is rough on your dryer vent

A Brooklyn renovation is a fundamentally messy event. Even a tight, well-managed gut job by a top-tier GC generates an enormous volume of fine particulate, and that particulate gets everywhere. We have the soot streaks on the inside of HVAC returns to prove it. The dryer vent, which is a long, narrow, smooth-walled pathway with airflow only when the dryer runs, is one of the worst possible places for renovation dust to settle and the hardest place to clean it out of after the fact.

There are five enemies of a dryer duct that show up during a renovation, and any one of them can compromise a vent that worked fine before the work started.

Drywall dust. Sheetrock is gypsum mixed with paper. Cutting, scoring, sanding, or drilling produces a fine, talc-like dust that gets into every cavity in the apartment. If your contractor opened any wall the duct passes through, drywall dust got in. Just cutting a sheet with a utility knife produces enough airborne dust to coat the inside of an open duct.

Joint compound dust. The dust from sanding the mud used to finish drywall seams. Finer than drywall dust, almost like flour. Sanding a single bedroom's worth of seams produces enough to coat a fifty-foot vent run. Joint compound dust is also slightly hygroscopic. When it lands on lint and the dryer is then used (warm, humid air), it binds the lint into a paste that is physically harder to remove than dry lint alone.

Framing wood splinters and sawdust. From cuts to studs, joists, and sub-floor. Sawdust packs tightly when wet. We have pulled splinters and pine sawdust clumps out of ducts under brand-new floors more times than we can count.

Screws, anchors, and small fasteners. Every contractor drops a screw or two during a build. In a renovation that opens the laundry wall, those screws sometimes fall into the duct when it is staged open. We have found drywall screws, plastic anchors, and once a snapped-off carbide drill bit, all sitting in the bottom of an elbow.

Polyethylene and plastic shavings. From appliance shipping film, new vinyl flooring, and cut PVC. This stuff melts at low temperatures. A new dryer pushes 130 to 160 F at the exhaust port. Plastic shavings soften and adhere to the duct wall, creating sticky points where lint accumulates faster.

Even a meticulous contractor leaves debris. We have inspected jobs by GCs we deeply respect, the kind who tape off room-by-room and run HEPA scrubbers all day, and we still find renovation residue in the duct. Dust travels. A dryer duct is a pipe with one end usually open to the apartment during construction. It catches dust the same way a gutter catches leaves.

For a baseline understanding of how Brooklyn dryer ducts work in general, the complete Brooklyn dryer vent cleaning guide is the place to start. This piece assumes you have the basics down and zooms in on the renovation-specific issues.

If your contractor opened a single wall that the duct passes through, drywall dust got in. We have never measured a post-renovation duct that was clean. Not once.

The four scenarios

Not every renovation puts your dryer vent at the same level of risk. We classify post-renovation calls into four scenarios, and we recommend a different intervention for each. The order is roughly worst to least bad, but even the lowest-risk scenario warrants attention.

Scenario 1: Full gut renovation

This is the worst case, and the one where customers are most surprised they have a problem. The customer logic is intuitive: the dryer is new, the duct was replaced or pulled through a freshly framed cavity, why would it be dirty?

Because even when the duct itself is brand new, a gut renovation almost always touches the shared shaft, the chimney, or the riser the duct terminates into. In a brownstone with a roof run, your new duct probably joins an older vertical shaft in the wall cavity or in a former chimney. That older shaft was almost certainly not cleaned during the renovation. Worse, cutting into the old shaft to splice in the new duct introduced fresh debris into a shaft that already had decades of lint, soot, and dust.

We have walked into post-gut jobs where the new horizontal duct is spotless aluminum, and the moment we extend the camera into the old vertical shaft we see a wall of compacted lint, plaster chunks from the cut-in, and a dead pigeon. The customer paid $400,000 for the renovation. The vent system above the spotless new horizontal is a fire hazard.

In gut jobs there is also a high probability that debris entered the shared shaft from above or below. If a unit on a different floor renovated at the same time or in the last couple of years, their debris is now your problem. Brooklyn buildings share more shafts than most owners realize.

Scenario 2: Kitchen and laundry renovation

The high-risk scenario. Almost every kitchen renovation in Brooklyn moves the laundry, even if only by two feet, even if the customer did not think of it as moving the laundry. The dryer position changes. The vent path changes. The contractor either reroutes the existing duct or installs a new one. This is where the largest number of code violations and installation mistakes happen, because the contractor is treating the dryer vent as a sub-component of the kitchen plumbing and HVAC rough-in instead of as the safety-critical exhaust pathway that it actually is.

The specific failure mode we see most often in this scenario is duct reuse. The customer assumes the contractor replaced the duct. The contractor assumed the existing duct was fine because it was already there. Nobody opened it to look. The new dryer is hooked up to a duct that was already due for replacement two renovations ago.

Scenario 3: Cosmetic-only renovation

Lower risk but still relevant. A cosmetic renovation does not open the duct, but it almost always produces drywall dust, paint dust, and sanding dust somewhere in the apartment. Dust travels. If your laundry closet was sealed during the cosmetic work, the duct interior is fine. But the laundry closet is rarely sealed, because the appliances live there and the contractor needs access. Even a "we just refinished the floors and painted" job introduces particulate to the duct exterior fittings, and any disturbance to the dryer (pulling it out to paint behind it, for example) can stress the existing duct connections.

The most common failure we see after cosmetic renovations is a duct that pulled loose at the back of the dryer when the dryer was moved and then reinstalled. The clamp is not all the way tight, and now the dryer is venting half its exhaust into the laundry closet for the next five years.

Scenario 4: Adjacent-unit renovation

This is the one customers never think about and the one that surprises us the most often. If your upstairs, downstairs, or next-door neighbor renovated, and your buildings share a vent shaft (which is common in Brooklyn co-ops and many brownstones), their renovation debris is now in your shaft. You did not authorize it. You did not pay for it. But your duct is now downstream of their drywall dust.

We have done jobs in Crown Heights where a customer called us because their dryer was running long. They had not renovated. Three units down the line, someone had done a kitchen gut six months earlier. The shaft was packed with drywall dust mixed with lint. Cleaning their unit alone got them airflow back, but we recommended the building commission a full-shaft service because the dust was not going to stay where it was. It would migrate up and down the shaft on every dryer run.

For more on how shared shafts work in older buildings, see our guide on why Brooklyn apartments have the worst dryer vent runs in America.

The biggest mistakes contractors make with dryer venting

We want to be clear before this section: most Brooklyn GCs are good at what they do. The handful of mistakes below are not because contractors are negligent. They happen because dryer venting sits at the intersection of HVAC, framing, and finish carpentry, and nobody owns it cleanly on the job site. The plumber thinks it is the HVAC sub. The HVAC sub thinks it is the GC's responsibility. The GC thinks the appliance installer handles it. The appliance installer hooks up the duct to whatever the GC leaves them. Nobody is treating the duct as a code-bound exhaust system, because nobody on the job is licensed for it specifically.

Here are the five mistakes we see most often.

Mistake 1: Reusing the existing duct without cleaning or inspecting it

The most common mistake by a wide margin. The contractor either explicitly reuses the old duct because moving it is expensive, or implicitly reuses it because the renovation scope did not include duct work and the existing duct was "fine." In either case, the old duct now connects to a brand-new dryer and is expected to perform like a new system. It will not.

A dryer duct is rated for a certain equivalent length, typically 25 feet for a standard residential install, with each 90-degree elbow counting as 5 feet. A clean duct at 35 to 45 feet equivalent length can still work with a high-end dryer. A duct with twenty years of lint and a fresh coating of drywall dust will not work, even at 25 feet. Reusing without cleaning is, functionally, installing a partially blocked duct on day one.

Mistake 2: Soffit terminations that dead-end inside the soffit

The one we hate most. The customer wanted the vent hidden. The contractor obliged by running the duct into a soffit, capping it with a louvered cover that looks like it terminates outside but actually opens into the soffit cavity. The dryer exhausts into the ceiling above the kitchen for the life of the installation.

We see this most where the architect wanted a clean facade and the contractor could not find a viable exterior wall path. The first sign is usually condensation staining on the kitchen ceiling six to twelve months in. The second sign is mold.

A soffit termination is allowed by code only if the soffit communicates directly with the outdoors. A dead-end soffit termination is a code violation and a structural hazard. We have torn down soffits with three pounds of wet lint sitting on top of recessed lighting cans rated for dry locations only.

Mistake 3: Sheet-metal screws to join duct sections

NFPA 211 prohibits sheet-metal screws to join dryer duct sections in the run, because the screw heads protrude into the airflow path and catch lint. A run with six screw joints will clog at the joints first, no matter how clean the rest of the run is.

The code-compliant method is foil tape (UL 181-rated) over a butt joint of two rigid sections, with the male end facing the airflow. Contractors who do this work every day know it cold. Contractors who do it occasionally get it wrong almost every time. We see screw joints in roughly two-thirds of post-renovation jobs we inspect.

Mistake 4: Foil-flex (semi-rigid flexible) duct inside walls

The thin, slinky-style foil-flex duct included with the dryer is rated for the visible connection from the dryer to the wall, typically up to 8 feet. It is not rated for installation inside wall cavities, joist bays, or behind drywall. Foil-flex compresses easily, kinks at corners, and is not rated to contain a duct fire long enough for occupants to evacuate.

The code-required material inside walls is rigid metal duct, typically aluminum at 0.018 inches minimum, smooth interior. NYC Mechanical Code is explicit. Foil-flex inside the wall is not a gray area. It is a violation. We find it in roughly one in three renovations we inspect.

Mistake 5: Routing through joists with kinks and over-tight bends

Even with rigid duct, the path through a joist bay can introduce kinks if the contractor used standard 90-degree elbows where the duct should have been swept with a long-radius elbow or a series of 45s. Tight bends increase static pressure, reduce airflow, and create high-velocity zones where lint impacts and accumulates.

We have measured 700 FPM at the back of a dryer and 130 FPM after a single tight 90 in a joist bay. The same install with a long-radius sweep would have lost maybe 80 FPM. The dryer is rated for 1,200 FPM minimum. Every elbow is a tax. Tight elbows are an exorbitant tax.

Mistake	Frequency we see it	Severity	Typical fix cost
Reused dirty duct	Very common	High (fire and airflow)	$350 to $525 (clean)
Soffit dead-end termination	Common	Severe (structural and mold)	$850 to $2,400 (rebuild)
Sheet-metal screws in joints	Very common	Medium (lint accumulation)	$275 to $550 (rejoint)
Foil-flex inside walls	Common	High (code and fire)	$1,200 to $3,800 (re-duct)
Kinked or over-tight elbows	Very common	Medium to high	$400 to $1,400 (reroute)

Pre-renovation: what to ask your contractor in writing

If you are reading this before your renovation starts, you are in the best possible position to avoid every problem we just described. The single highest-leverage action you can take is to put the duct specification in writing in the contract or in a formal scope-of-work addendum. Verbal assurances from the GC are not enough. Even with a GC we trust, we recommend customers get the following in writing.

Here is the language we suggest including. Adjust to your situation, and have your architect or attorney review.

Duct material. Rigid aluminum or galvanized steel, minimum 0.018 inches thick, with smooth interior walls. No foil-flex inside walls, ceilings, or floor cavities. Foil-flex permitted only in the visible connection from the dryer to the wall, maximum 6 feet, secured with worm-drive clamps (not duct tape).

Joint method. All joints sealed with UL 181-rated foil tape. No sheet-metal screws or rivets in the airflow path. Male ends facing downstream airflow. All horizontal runs pitched 1/4 inch per foot toward the termination to prevent moisture pooling.

Run length and elbow count. Total equivalent length calculated and documented, with each 90-degree elbow counted as 5 feet of equivalent length and each 45-degree elbow counted as 2.5 feet. Total equivalent length not to exceed the dryer manufacturer's maximum specification (typically 25 to 45 feet depending on the model). If the path requires more, a booster fan to be specified, with model number and electrical requirements documented.

Termination type. Exterior termination only. No soffit terminations unless the soffit communicates directly with the outdoors via a sealed pathway. Termination cap to be a louvered hood with damper, not a screen. Damper to be field-tested before final close-out. Termination location to be at least 3 feet from any operable window, door, or air intake.

Post-installation airflow measurement. Contractor to measure airflow at the dryer connection using an anemometer immediately after install. Minimum acceptable reading: 1,200 FPM with dryer on high heat, no load. Reading to be documented in writing and provided to homeowner before close-out.

Before-and-after photos. Contractor to provide photos of the duct path before drywall closes, showing all elbows, joints, and the termination. Photos to be saved as part of the project documentation.

If your GC pushes back on any of these items, that is the signal to ask harder questions. Every one of them is achievable with a modest amount of attention and exactly zero of them are exotic. We have written this language into so many addendums at this point that some Brooklyn architects have started including it as standard.

For the regulatory context behind these requirements, see the NYC building code piece on Brooklyn dryer venting.

During renovation: when to call us

The highest-leverage point in a renovation to inspect the dryer duct is after the rough-in is complete and the duct is installed, but before drywall closes. We call this the pre-rock-up audit. If you are reading this and your renovation is in progress, this is the call to make today.

At the pre-rock-up stage we can:

• Visually inspect the entire duct path. Once drywall closes, the duct is invisible until something goes wrong.
• Verify the duct material and the joint method against the spec we recommended above.
• Measure airflow with a dry run (we bring a portable blower that simulates a dryer load).
• Run a borescope camera the full length of the duct to confirm there are no obstructions, kinks, or debris.
• Photograph everything for the homeowner's records.
• Issue a written report that can be referenced at close-out and used as leverage if the GC needs to make changes.

The cost of fixing a duct issue before drywall is roughly one-fifth the cost of fixing it after. Open the drywall later and you are not just paying for the duct fix. You are paying for the drywall cut, the patch, the re-mud, the re-paint, and the dust mitigation. Pre-rock-up audits are the cheapest insurance in the renovation.

We typically do the audit on the same day your GC schedules the rough-in inspection with the city. It is the natural breakpoint in the schedule. The audit takes 60 to 90 minutes for a typical Brooklyn apartment and 90 to 120 minutes for a brownstone with a long vertical run.

Post-renovation: the mandatory clean

Even with a perfect pre-rock-up audit and a brand-new duct, we strongly recommend a post-renovation clean within 30 days of move-in. The reason is straightforward. Drywall dust, joint compound dust, and the fine particulate from sanding and finishing settle on every surface in the apartment after the GC packs up. The duct is no exception. It does not matter how much the cleaning crew vacuumed. It does not matter how new the duct is. There is a layer of fine dust on the inside of that duct, and the first time the dryer runs, that dust binds with lint.

The dryer is the worst possible appliance to be running through a freshly built duct full of construction dust. The dryer pushes warm, humid air. The dust is hygroscopic. The two combine into a paste-like coating on the inside of the duct, and from that point on, every load of laundry adds another layer of lint that adheres to the paste rather than passing through to the termination.

We have measured ducts that were installed clean on day one, used normally for 30 days, and then inspected. The lint accumulation in those 30 days is two to three times what we would expect in 30 days of normal operation in an established home. The renovation dust does not go away on its own. It binds, it accelerates lint adhesion, and it stays.

The post-renovation clean is a full-service clean: tech on both ends of the duct, mechanical brush through the entire run, HEPA-vacuum capture at the dryer end, termination cap removed and serviced, damper checked, and airflow measured before and after. We document the airflow delta in writing. On a typical post-renovation clean in a Brooklyn brownstone, we see airflow improvements of 40 to 70 percent compared to the pre-clean reading. On apartments with shorter runs, the improvement is usually 20 to 40 percent. Either way, the customer is getting back airflow that the renovation cost them.

For a deeper look at what a real clean involves, our piece on Bed-Stuy and Crown Heights dryer vent cleaning has the play-by-play with photos.

The "renovation-adjacent" clean

This is the section that surprises customers the most. If your upstairs, downstairs, or adjacent-unit neighbor renovated, and your buildings share a vent shaft, you need a clean too. The debris from their renovation entered the shared shaft, and from the shared shaft it migrated into your duct.

Migration happens because of pressure differentials. When their dryer runs, their duct pushes air (and dust) into the shared shaft. When your dryer is off, the shaft is at a lower pressure than your duct, and air (and dust) flows backward into your duct. Over the course of weeks of mixed dryer use across the building, the debris from any one renovation reaches every connected duct on the shaft.

The classic Brooklyn shared-shaft buildings are post-war co-ops, but we have also seen shared shafts in pre-war brownstones converted to multi-family use. In Brooklyn Heights and Park Slope co-ops it is common to find three to six units connected to a single vertical shaft. One unit's renovation affects all of them.

If your building board sent a notice that a neighbor was renovating, that is your signal to schedule a clean within 60 to 90 days of their work completing. For the co-op-specific dynamics, our piece on Brooklyn co-op and condo dryer vent cleaning is the deeper read.

Pricing

Here is what the renovation-related work costs in Brooklyn as of our 2026 price book. These are typical ranges. Long brownstone roof runs and difficult terminations push toward the high end. Short apartment runs sit at the low end.

Pre-rock-up audit. $175 to $275. Includes 60 to 90 minutes on site, full visual inspection, borescope camera scan, dry-run airflow measurement, and written report with photos. Pre-renovation language review (the contract addendum we discussed above) included free if you book the audit. We charge a flat fee for this regardless of building type because the time on site does not vary much. Most of the time is the camera scan and writing the report.

Post-renovation deep clean. $350 to $525 for a standard Brooklyn apartment or brownstone run. Includes both-end access, mechanical brushing, HEPA vacuum capture, cap removal and service, damper inspection, airflow measurement before and after, and a written report. The price reflects the additional time required to remove construction dust binding, which is typically 1.5 to 2 times the time of a standard clean.

Renovation-adjacent shared-shaft clean. $400 to $625 per unit, with discounts for booking multiple units in the same building on the same day. We can usually do three to four units back-to-back on a single visit, which keeps the per-unit cost down. Buildings that book all affected units together typically save 15 to 25 percent versus individual scheduling.

Reroute or re-duct work. Variable. Common scenarios: replacing an in-wall foil-flex section with rigid aluminum runs $1,200 to $3,800 depending on access. Rebuilding a soffit termination as an exterior termination runs $850 to $2,400. Replacing a single problem elbow with a long-radius sweep runs $400 to $1,400. We work with a small set of trusted GCs in Brooklyn for the structural side of this work. We do the duct, they do the framing and finish.

We do not charge for the consultation call, and we will not pressure-sell a service you do not need. If your pre-rock-up audit shows the duct is in spec and clean, we tell you that and you owe us nothing beyond the audit fee. We are not paid on commission and we do not have a quota.

To book any of the above, call us at (718) 541-5567 or use /book on this site.

Real walkthrough: a Carroll Gardens renovation, October 2025

Here is one job from last fall, lightly anonymized.

The customer was a couple in Carroll Gardens. Three-story brownstone, owner-occupied. They did a full gut renovation of the parlor and second floors. New kitchen, new master bath, new laundry closet on the second floor. LG electric stacked dryer. Midsize Brooklyn GC we have worked with before. April to August 2025. They moved back in early September.

By the second week of September they noticed two things: the dryer was running long (a load that used to take 50 minutes was now taking 90 to 100), and there was a faint musty smell in the second-floor hallway when the dryer was running. They called us in late September.

Two techs, 90 minutes on site. What we found:

The dryer-to-wall connection was a 4-inch foil-flex jumper, 5 feet long. Fine. The wall penetration was a 4-inch rigid aluminum stub. Fine. The duct path ran horizontally 8 feet through a soffit above the new kitchen, then turned 90 degrees vertical up through the third floor and out the roof. Total path length approximately 42 feet, two 90s, one 45.

The horizontal section was rigid aluminum. The vertical section was foil-flex. The contractor had used foil-flex inside the wall cavity for three stories. Code violation. Fire hazard. The foil-flex had also kinked at the elbow into the vertical section.

The roof termination was a louvered hood with a damper. The damper was stuck partially closed by dried joint compound on the hinge.

We pulled the cap and ran the camera. The first 15 feet from the roof down was coated in pale gray dust mixed with lint. The vertical foil-flex section below was packed with a paste-like residue, the renovation-dust-plus-dryer-moisture binding we described earlier.

Airflow at the back of the dryer measured 290 FPM. The LG spec for that model is 1,200 FPM minimum.

We could not just clean the duct, because the foil-flex in the wall would re-fail within months even after a clean. Two options. Option A: clean as-is, get airflow to maybe 800 to 900 FPM, but leave a code violation. Option B: coordinate with their GC to re-duct the vertical in rigid aluminum, then do a full clean.

They chose B. The re-duct took the GC two days. We did the clean on day three. Final airflow: 1,340 FPM. The dryer now dries a load in 45 minutes. The hallway no longer smells musty.

Total cost: pre-inspection $225, GC re-duct (separate billing) approximately $2,800, post-re-duct clean $475. Compared to a hidden code violation that eventually causes a duct fire or wall mold remediation, it is not a difficult math.

For more on the fire-risk side, see Brooklyn dryer vent fires and prevention. That is the case we think about when we find foil-flex in a wall.

The renovation checklist for Brooklyn homeowners

If you take nothing else from this article, take this checklist. Print it, save it, send it to your GC.

Before renovation begins:

• Put the duct material spec in writing: rigid aluminum or galvanized steel, minimum 0.018 inches, smooth interior, no foil-flex inside walls.
• Put the joint method in writing: foil tape, no screws, male ends downstream.
• Put the run length and elbow count in writing: total equivalent length not to exceed dryer manufacturer's spec, with elbow count documented.
• Put the termination type in writing: exterior termination, louvered hood with damper, no soffit dead-ends, minimum 3 feet from operable windows.
• Put the airflow verification in writing: contractor to measure airflow with an anemometer at close-out, minimum 1,200 FPM, documented in writing.
• Put the photo documentation in writing: pre-drywall photos of the entire duct path.

During renovation:

• Schedule a pre-rock-up audit with us once the duct is installed and before drywall closes. This is the cheapest insurance you can buy.
• Walk the duct path yourself before drywall closes. Look at every joint. Look at every elbow. Take your own photos.
• If anything looks wrong, flag it before the wall closes. After the wall closes, every fix is five times more expensive.

After renovation, within 30 days of move-in:

• Schedule a post-renovation clean. Yes, even with a brand-new duct. Especially with a brand-new duct.
• Check the laundry closet for any debris around the dryer connection.
• Run your first three loads with the lint trap fully visible. Pull it after each load and look at the lint volume. Renovation-affected ducts often show abnormally large or oddly colored (gray, dusty) lint on the first few loads.
• Check the exterior cap. If you can see it from the ground, look at it. A new cap should open cleanly with airflow and close cleanly without. If it sticks, the damper needs service.

If a neighbor in your building renovated:

• Schedule a renovation-adjacent clean within 60 to 90 days of their work completing.
• If the building has multiple connected units, coordinate with the board to get the shared shaft serviced.
• Check your dryer performance before and after. If your dryer was running long before they renovated, you have an underlying issue that the neighbor's debris is making worse, not a problem the neighbor caused.

Annually after the renovation:

• Schedule a standard clean every 12 to 18 months for the first three years post-renovation. Renovation dust takes a couple of seasons to fully clear from the duct system, and the first few cleans are usually more productive than steady-state cleans.
• After year three, settle into the standard Brooklyn cleaning cadence based on building type. Our piece on how often to clean a dryer vent in Brooklyn has the cadence breakdown.

FAQs

My contractor said the vent was fine. Do I still need an inspection?

Yes. We are not impugning your contractor. The inside of a 50-foot duct in a wall is not something the contractor can see, and "fine" usually means "I did not see anything wrong." Our borescope camera sees what the contractor cannot, and our airflow measurement gives a number. A number is more useful than "fine." If the duct is genuinely in spec and clean, the inspection takes 60 minutes, we tell you so, and you move on with confidence.

What if my building requires a final clean as part of a co-op move-in?

Some Brooklyn co-op boards require documentation of a dryer vent clean before allowing a shareholder to occupy after a renovation. We do this work regularly. We provide a signed and dated certificate with the airflow reading, photos of the duct interior, and the technician's name. If your board has a specific form, send it to us in advance.

What about new construction condos?

New construction is its own category. The duct is brand new but so is the building, which means residual construction dust in the shaft and termination. We recommend a clean within the first 90 days of move-in for any new construction condo, and another at the 12-month mark. Williamsburg waterfront condos and DUMBO conversions are the two segments where we see the most first-year buildup, because both have shared vertical shafts that collect dust from the entire building's construction sequence.

The contractor used foil tape but also put one or two screws to hold the joint. Is that still a violation?

Yes. NFPA 211 prohibits any screws, rivets, or sharp protrusions in the airflow path. Even one screw at one joint creates a lint snag. The fix is removal of the screws and re-taping the joint. A 15-minute fix per joint when caught early.

Can I clean the duct myself after the renovation if I am handy?

For a short, straight, single-floor run with full access at both ends, yes. For a brownstone roof run or a co-op shared shaft, no. The brush we use is 50 feet long with whip heads, and the roof work is not intuitive. For most Brooklyn customers, the answer is hire a pro.

My GC offered to clean the duct as part of close-out for $150. Is that good enough?

It depends entirely on what they actually do. A $150 GC clean is usually a 20-minute pass with a leaf-blower attachment or a shop-vac at the dryer end. That removes loose lint near the dryer. It does not address dust binding in the rest of the duct, it does not service the termination, and it does not measure airflow. Ask four questions: do they brush the full run, service the termination cap, use HEPA capture, and measure airflow before and after with a written report. If any answer is no, you are not getting a real clean.

How long should the post-renovation clean take?

For a Brooklyn apartment with a wall-vented run under 20 feet, 60 to 90 minutes. For a brownstone with a roof run of 30 to 50 feet, 90 minutes to 2 hours, with one tech on the roof and one at the dryer. For a co-op shared-shaft unit, 75 to 110 minutes. If a company quotes you a 20-minute job, they are not doing it right.

What is the worst post-renovation duct you have ever seen?

A Park Slope brownstone where the GC had run foil-flex from the second-floor laundry up through three stories of joist bays, made three 90-degree turns inside the wall, and terminated into a dead-end soffit on the fourth floor. Eight months later, the soffit had a mold colony on the inside of the drywall. The duct itself had so much compacted lint and drywall paste we cut sections out rather than brush them. Total remediation: about $11,000. We cite that job when customers ask whether the pre-rock-up audit is worth it.

Does the duct need to be cleaned even if the dryer is brand new?

Yes. A brand-new dryer through a renovation-affected duct is the worst combination. The new dryer pushes more airflow and humidity. The renovation dust binds with the moisture. Lint accumulates faster than in an established system. New dryer plus new duct plus skipped post-renovation clean is the recipe for the dryer to run long and the customer to be confused.

Does the airflow measurement actually matter, or is it just a number?

It matters. Below the dryer's target airflow, drying time goes up, heat in the laundry closet goes up, lint accumulation accelerates, and the dryer's safety thermostats cycle more often, shortening its lifespan. A reading below 800 FPM at the dryer connection is functionally a slow dryer and a fast-clogging duct. Below 500 FPM is genuinely dangerous. The measurement is the diagnostic.

My building manager said the building services the shafts annually. Do I still need a unit-level clean?

Building-level service is usually limited to the shared vertical and does not include the horizontal run from your unit's dryer to the shaft. Your horizontal run is not on the building's service contract. You still need a unit-level clean.

We are here when you need us

If you are mid-renovation, just finished one, or thinking about starting one, call us. The pre-rock-up audit is the highest-leverage call you can make on the renovation. The post-renovation clean is the second-highest. The renovation-adjacent clean for affected neighbors is the third. None of this is expensive relative to the renovation itself, and all of it is cheaper than fixing a mistake after the wall closes.

We are Vent Pro NYC. We have been working Brooklyn dryer vents long enough to have seen every renovation mistake at least twice. We tell you what the duct needs and we either do the work or we tell you it is fine.

To schedule, call (718) 541-5567 or use /book. We keep mornings open for renovation calls.