How Much Does It Cost to Repair Ductwork in a Crawl Space? [2025 Data]

Repairing Ductwork in a Crawl Space Cost Factors 

While the largest cost factor is the type of repair required, the cost of working under a house or in the attic is something not many want to do. Because of this, you’re going to pay more than you would for the same work done on exposed ductwork.

Type of Repair 

Whether it’s a minor leak or fully replacing a section of ductwork, the type of repair will impact your cost.

Simple Leak Repair With Tape or Mastic

Ironically, duct tape doesn’t really work on ducts. Because the adhesive melts at high temperatures, you’ll want to use special tape for fixing minor leaks. Mastic works as well; just make sure it’s specifically for ducts, as it needs to be both resistant to high temperatures and safe to breathe. While checking for air duct leaks can cost $150 to $450, it’s less expensive to fix it—especially if you DIY. 

Swapping a Section of Ductwork

A full air duct replacement costs $3,500 on average, but you likely won’t need to take it that far. Most ducts, whether they are made from fiberglass or sheet metal, can be cut and replaced with newer sections. This fix is only really suitable though if a section of ductwork was damaged beyond repair. Otherwise, you may need to replace every duct.  

Mold or Asbestos Removal and Cleaning 

Some experts recommend air duct cleaning every three to five years. If mold or other harmful biological growth is noticed during an inspection, you’ll need to clean it. On average, air duct cleaning costs around $400, but the price is worth the clean air and peace of mind. While some repairs can be DIY, mold removal is better left to the pros. 

If a pro finds mold in the ducts, remediation will be necessary. Removing mold costs $375 to $7,000, depending on severity. For health reasons, professionals must also eliminate asbestos from ductwork. Hiring a pro to remove asbestos costs $450 to $6,000. 

Adding or Replacing Insulation

Insulating ducts in a crawl space is no easy feat. While you can try wrapping your ductwork, it needs to be in good condition, and you better be ready to be uncomfortable for long stretches of time. The insulation itself costs around $100 per 25 linear feet, but the real cost is the time required to insulate your duct sufficiently.  

Securing Loose Ducts

Sometimes you don’t need to replace your air ducts—you just need to tighten them down. Any rattling or banging noises coming from your crawl space could mean your ductwork is loose. Consider crawling into the space and locking everything down or hiring a pro to handle the work at a cost of $40 to $80 per hour.  

Removing Obstructions

Removing obstructions in your ducts can either be quite cost-efficient or, in some cases, pretty expensive. If the obstruction is large enough, you’re better off removing the section and replacing it. If no materials are required, expect to pay the hourly rate above. 

Accessibility 

Accessibility is a major concern when it comes to ductwork repair. There isn’t much room to maneuver, especially in a crawl space. If the crawl space is especially difficult to access, it will increase the overall price by around 5% to 10%. The same is true if the laborer finds that excavation into a wall is necessary to complete the work. 

Size 

While the largest factor is the type of repair required, the size of your ductwork matters too—especially if you plan on replacing large sections. While each repair has a different cost basis, you can see below how the length of the ductwork impacts the total project cost. Due to the wide range of materials and labor time required, the average estimated cost is about $275 per 10 linear feet. 

Duct Material 

There are several types of ductwork materials, but they fall into three categories: rigid, flexible, and insulated. Rigid ducts made from aluminum or steel are prone to corrosion and leaks. Repairs range from $300 to $2,100, depending on the type of damage and its extent. 

Flexible ductwork is fairly common, as it's an excellent choice for routing through tight spaces. However, it’s less durable than rigid ductwork. Repair costs average from $100 to $800. Insulated ductwork, which is flexible ductwork wrapped in insulation, costs between $200 and $1,200 to repair.

Labor 

General labor will cost between $40 and $80 per hour. Hopefully, you don’t require specialized equipment or professionals with certain licenses—such is the case with mold contamination—as those hourly rates can be between $50 and $120 or more. For repairs, you’ll likely be quoted in hours. For larger jobs, expect a more detailed cost breakdown. 

Repairing Ductwork in a Crawl Space vs. Replacing

There are a few instances where you should consider replacing your ductwork. Mold issues, pest infestations, and severe damage are all costly and complicated fixes. While they may cost 75% more than a repair, they are often the better choice.

That being said, you can do many minor repairs yourself. Taping or sealing an obvious duct rip can be satisfying and cost-effective. You can wrap your ductwork in installation, provided you can get to it. A general rule is to hire a local ductwork professional if the ducts are contaminated or if the job takes too much time or requires more than 10 minutes of research.    

DIY Repairing Ductwork in a Crawl Space vs. Hiring a Pro 

You may consider DIY ductwork repair in a crawl space. However, there are some drawbacks to going it alone. Safety complications could arise due to unknown contaminants, and there’s also the potential for costly or dangerous mistakes.

When you hire a duct pro, you’re paying for licensing and years of expertise. Professionals are extremely efficient compared to DIYers, and while their hourly rates might be high, they can work much faster than most homeowners. The key is to get a range of quotes from different contractors and hire someone you trust. 

Tips to Reduce Cost While Repairing Ductwork in a Crawl Space 

There are a few ways you can lower costs when repairing ductwork in a crawl space:

• Handle simple repairs yourself. 

• Hire professionals outside of busy seasons, like deep winter or high summer. 

• Shop around—the best deals might not be at the closest store. 

• Sign up for blanket discount codes from home improvement stores. 

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.