Dryer Vent Cover Repair, Replacement & Installation: How the Job Actually Goes

From the sidewalk, three very different jobs look identical. Somebody works on the outside of your building for a while and leaves you with a vent hood that works. Underneath that, we are doing one of three things: repairing a sound hood, replacing a finished one, or installing a proper termination where there never really was one. Which of the three you need decides how long we are there, what we bring, and what it costs.

We are Vent Pro NYC, a family-owned vent crew working across Brooklyn, the rest of NYC, and Deal, NJ, and this piece is about the work itself, from our side of it. If what you want is help figuring out which kind of termination you have, that is answered in our roof, wall, and soffit guide. If you want to know whether your cover is failing at all, run the checklist in our self-inspection guide first.

Three jobs, and how they differ

Repair is what we do when the hood body is fundamentally sound. The metal is straight, the flange is tight to the wall, the throat is the right diameter, and the only thing wrong is a moving part or a seal. That means a new flapper or damper assembly, a new pivot pin, re-seating the hood, and re-sealing the perimeter. It is the fastest of the three and usually happens inside a cleaning visit without a second trip.

Replacement is what we do when the hood itself is finished. Brittle chalky plastic, a cracked body, a bent hood that will never let a flap seat flat, rust through the throat, or a hood that is the wrong type entirely — a bath-fan cap or an attic soffit grille with mesh in it. The duct and the wall penetration are fine, and a correct hood goes on in place of the wrong one.

Installation is what we do when there is no proper termination there at all. A duct that stops inside a soffit cavity. A duct that ends behind a loose piece of siding. A new laundry location that needs a wall cut. A run that was re-terminated during a renovation and never finished. Installation is the longest of the three because it involves the penetration itself, the duct connection, flashing, and sealing — not just the part you can see.

We separate them out of honesty about scope. Plenty of customers call asking for a replacement and need a repair, which is less work than they expected. Plenty of others ask for a repair and are looking at an installation, because the hood they wanted fixed was never properly connected to anything.

What we look at before deciding

We do not decide from the ground. Before quoting the work, we check a specific list, and most of it is not visible until the hood comes off the wall.

• Hood material and condition. Plastic or metal, and how much life is left. Chalky, cracked, or brittle plastic is a replacement regardless of what else is true.
• Damper condition and travel. Does the flap swing fully open under exhaust pressure, and does it close flush with spring tension when the dryer stops. A flap with partial travel is a fail even if it looks intact.
• Throat diameter versus duct diameter. Any reduction is a permanent restriction. A four-inch duct necked into a smaller hood is a defect we correct, not one we work around.
• Whether the duct is actually connected to the hood. This is the one that surprises people. We regularly find a duct that terminates short of the hood, particularly in soffits, so the exhaust is discharging into the cavity. Our termination guide covers why that is the most expensive failure in this whole category.
• The condition of the substrate, and evidence of water intrusion. Brick, brownstone, stucco, wood siding, or vinyl, and whether the material behind the flange is still sound. Staining below the hood or soft sheathing turns a hood swap into a hood swap plus proper flashing.
• Whether there is a screen on the lint path, and how dirty the duct behind the hood is. The first comes off. The second usually decides whether this is one visit or two.

The anatomy of a proper dryer vent hood

There are only four things that matter about the part itself, and every one of them is a place cheap hoods cut corners.

The hood body. It has to shed water away from the wall, stand off far enough that the flap has room to swing fully, and hold its shape. Metal holds its shape. Plastic does for a while and then does not.

The damper or flapper. A single hinged flap with a torsion spring, a bank of louvers, or a gravity damper on a horizontal pivot. Whatever the style, the requirement is the same: it opens freely under exhaust pressure and closes flush when the dryer is off. That closure is what keeps birds, mice, and cold air out of your duct.

The wall collar. The sleeve that passes through the wall and connects the hood to the duct. It has to match the duct diameter and actually join the duct, with a sealed connection, not a rough overlap held together by hope.

No screen on the lint path. This is not us being fussy. The code is explicit about it.

"Exhaust ducts shall terminate on the outside of the building... The exhaust duct termination shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination." — IRC M1502.3

Lint mats onto mesh until the mesh is a solid disk, at which point you have a restriction that causes exactly the overheating you were trying to avoid. If your existing hood has mesh behind the louvers, that mesh is the reason your dry times are long, and it comes off.

Material and sizing decisions

Metal over plastic, in almost every case. Brooklyn facades get direct summer sun, hard winter freezes, and salt air along the harbor side. White plastic hoods go chalky and brittle under that, and the hinge cracks first. A galvanized or aluminum hood outlasts them by a wide margin, and it also resists a squirrel deciding to chew the opening wider.

Four inches, matched end to end. Residential dryers are designed around a four-inch duct, and every reduction costs you airflow permanently. Where we find a reducer, we correct it rather than reinstall it.

The damper style follows the termination. Spring-loaded flappers work well on wall terminations at any height. Gravity dampers are common and reliable on roof caps, where the install angle does the work. Soffit terminations need a dedicated dryer soffit cap — a louvered grille with a damper and no mesh — not the generic attic-ventilation grille that gets used by mistake. The full pest-resistance specification is in our pest-resistant cover guide.

The transition hose is a separate decision. NYC does not permit foil or white plastic flex hose for the connection between dryer and duct. What gets installed is rigid or UL-listed semi-rigid metal. If we are already at your machine for cover work, this is usually worth handling at the same time. Both are covered on our repair and installation page.

How the work goes on a Brooklyn wall termination

A wall or sidewall termination is the straightforward version, and it is what most ground-floor and garden-floor Brooklyn apartments have.

We pull the dryer, disconnect the transition hose, and seal a HEPA vacuum to the wall stub so anything we dislodge from outside gets captured rather than blown into your laundry room. Outside, the old hood comes off — screws, then the flange, then whatever sealant a previous installer used, which is frequently the wrong sealant applied generously. We clean the penetration, check the wall collar, and inspect the substrate for water damage that was hiding behind the flange.

The new hood goes on with the collar properly joined to the duct, the flange bedded in sealant, fasteners appropriate to the substrate, and the hood pitched very slightly down and out so water drains away from the building rather than back into the duct. Then we run the dryer and watch the flap: full travel open under pressure, flush closure when the machine stops. Finally an airflow reading, so the improvement is measured rather than assumed. That is a contained piece of work, and it pairs naturally with a cleaning on the same visit.

Why the roof is a different visit

A roof or parapet termination is not the same job with a ladder added. It is a different job.

Getting to the cap means either an extension ladder set safely from a yard, or a roof hatch from inside the building — and Brooklyn roof hatches are frequently painted shut, located in a top-floor closet, and last opened during a roof replacement nobody remembers. That access alone can consume a meaningful part of the visit before any work starts.

Once we are up there, the work has a component that wall terminations do not: the roof penetration is a waterproofing detail. A cap sits in a curb or a jack integrated with the roof membrane or the parapet flashing. Pulling that cap disturbs that integration, and setting the new one means restoring it properly. Getting it wrong does not produce a slow dryer. It produces a leak into the top floor, which is a far more expensive mistake than the one we came to fix. Weather gates the work too — we are not opening a roof penetration in rain, high wind, or ice.

So we quote roof cap work as its own visit with its own access plan, and we say so up front rather than discovering it on the day.

Flashing and sealing, so you do not create a leak

The most common way a well-intentioned vent cover job goes wrong is that somebody solves the airflow problem and creates a water problem.

Every exterior termination is a hole in a weather barrier. The hood's job is to be a proper part of that barrier, which means the flange has to shed water outward and downward, sealed in a way that matches the substrate. Brick, brownstone, stucco, wood siding, and vinyl each want a different approach, and the sealant that works on one will fail on another. Sealing a hood to brick with an interior-grade caulk is a repair that lasts one winter.

Two details we hold to on every install. The hood is pitched slightly downward and outward — never level, never tipped back — so condensate and driven rain leave rather than run into the duct and wet the lint bed. And duct joints are sealed with foil tape or an appropriate sealant, never cloth duct tape, which dries out and releases, and never with screws that project into the airstream, because every projection into a dryer duct is a lint snag.

If we find staining below your existing hood, we tell you at the quote stage that the job now includes correcting whatever has been letting water in.

Landmarked facades, co-ops, and permission

Brooklyn adds a permission layer that most places do not.

If your building is in a landmarked district — much of Park Slope, Brooklyn Heights, Cobble Hill, Fort Greene, Clinton Hill, and a good deal of Bed-Stuy and Crown Heights — changes to a visible facade can require approval. A like-for-like replacement in an existing opening is generally a far simpler conversation than cutting a new opening on a street-facing wall.

In a co-op or condo, the exterior wall and the exterior cap are typically the building's, not yours, even when the duct inside your wall is yours. That means the managing agent or the board usually needs to be in the loop, and the building will want a certificate of insurance before anyone touches the facade. We carry a million dollars in liability coverage and send the COI ahead of the visit as a matter of routine. The full approval chain is laid out in our Brooklyn co-op and condo guide.

None of this is a reason to put the work off. It is a reason to start the conversation before the hood fails completely rather than after.

Why a new cover on a dirty duct is a wasted trip

This is the part we say to nearly every customer who calls about a hood.

A vent cover and the duct behind it are one system. A restricted duct means the exhaust never generates enough pressure to open the new flap fully, so your new hood underperforms from day one, and the lint bed that built up while the old cover was failing will pack against the new damper and start the cycle over.

There is a practical argument too. We are already at your dryer, already sealing a vacuum to the wall stub, and already outside at the termination with the hood off — the single best access we will ever have to that duct.

So on most cover jobs we quote the cover work alongside a cleaning, and every cleaning visit ends with a before-and-after airflow reading and a written report you keep. If the duct genuinely was cleaned last season, we will say so and skip it.

Frequently asked questions

Can you just replace the flapper instead of the whole hood? Often, yes, and it is the cheapest thing we do. If the hood body is straight, the flange is tight, and the throat is the right size, a new damper assembly and pivot pin restore it completely.

How do I get a price without an appointment? Text a photo of the outside vent to (718) 541-5567. A clear picture of the hood, ideally with a little surrounding wall in frame for scale, tells us the termination type, the material, the damper style, and most of the time the fault.

How long does the work take? A flapper swap on a reachable wall vent is quick. A full hood replacement on a wall termination fits alongside a cleaning. Roof and parapet caps are their own visit because of access and the waterproofing detail. Anything involving opening a soffit panel or correcting water damage may need a return trip, and we tell you that at the quote rather than on the day.

Do you install a vent where there is no exterior opening at all? Yes, that is the installation case, and it is quote-only because the variables are the wall construction, the route, the permission situation, and what is inside the wall. New penetrations on landmarked or co-op facades need approval first, and we will tell you what that path looks like.

Will a new cover fix my long dry times by itself? Sometimes, if the cover was the whole restriction — a mesh screen, a frozen flap, a nest at the throat. More often the duct behind it is the other half of the problem, which is why we pair the two.

Get a quote on your vent cover

The fastest thing you can do right now is take one photo of the outside vent and text it to (718) 541-5567. Most of the time we can tell you from the picture whether you are looking at a repair, a replacement, or an installation, and give you a number without a trip.

Vent Pro NYC is a family-owned crew, licensed, insured, and working in NYC for more than ten years. Vent cover work is quoted in writing before anything gets touched, and it is guaranteed. Request an estimate or call or text (718) 541-5567, Sunday through Thursday 7am to 7pm and Friday until 3pm.