Thermal wrap and condensation scope

Duct Insulation Cost Calculator (2026)

Estimate R-6 or R-8 duct wrap by accessible length, attic or crawl-space access, old-insulation removal, air sealing, vapor barrier, and condensation conditions.

Direct answer

Professional duct insulation often plans around $7-$24 per linear foot, or roughly $1,500-$4,500 for an accessible 150-foot project. This page prices thermal insulation. Use duct sealing for leakage and duct repair for crushed, torn, or disconnected sections.

Duct Insulation Cost per Linear Foot

Scope	Planning range	Why the range changes
Open basement or utility-area ducts	$7-$14 per linear ft	Good access can reduce labor; verify whether code or comfort goals require insulation in that space.
Attic duct wrap	$10-$20 per linear ft	Heat exposure, limited footing, existing wrap, sealing, and continuous vapor-barrier details affect labor.
Crawl-space duct wrap	$12-$24 per linear ft	Low clearance, ground moisture, contamination, supports, and wet material can change or stop the work.
Remove old or wet insulation	$3-$8+ per linear ft	Disposal and safe handling are separate from new wrap; remediation is not assumed.

Correct Order of Work

1. Diagnose moisture. Find roof, plumbing, crawl-space humidity, condensation, or air-leakage sources before covering the duct.
2. Repair the duct. Replace crushed, torn, wet, contaminated, unsupported, or undersized sections.
3. Seal accessible joints. Treat leakage at seams, takeoffs, boots, and plenums before insulation hides them.
4. Install a continuous assembly. Specify R-value, sealed seams, vapor-barrier continuity, support, and clearance.
5. Verify. Inspect all sides, record dry conditions, and confirm airflow or leakage testing promised by the bid.

Condensation Is a Symptom

New wrap may fail again if humid air reaches a cold duct through gaps in the vapor barrier, if duct leakage chills the exterior, or if bulk water and crawl-space moisture remain. Require the contractor to name the suspected cause and the condition that will be verified before closure.

Compare Local Duct Insulation Quotes

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R-6 vs. R-8 Quote Questions

What installed R-value and product are included, and which local requirement applies?
Does the stated value cover fittings, boots, plenums, and difficult transitions?
How will seams, penetrations, compression points, and vapor-barrier damage be closed?
Are supports being adjusted so insulation is not pinched or left against wet surfaces?
Which old material, cleanup, access, testing, and remediation items are excluded?

Choose the Correct Duct Task

Seal otherwise sound, leaky ducts Repair localized physical damage Replace widespread failed ductwork Design a new supply-and-return system

FAQ

How much does duct insulation cost?

Accessible residential duct insulation commonly plans around $7-$24 per linear foot depending on location, access, R-value, old-wrap removal, sealing, vapor-barrier work, and moisture conditions. A 150-foot project may plan around $1,500-$4,500 before remediation or duct repair.

Should ducts be sealed before they are insulated?

Usually, accessible joints and penetrations should be inspected and sealed before new insulation covers them. The proposal should separate air-sealing scope from thermal insulation and document large repairs first.

Is R-8 duct insulation better than R-6?

R-8 provides more thermal resistance, but the correct requirement depends on duct location, climate, adopted code, available clearance, and the complete assembly. Ask the contractor to state the installed R-value and code basis.

Will duct insulation stop condensation?

It can reduce surface condensation when the insulation and vapor barrier are continuous, dry, correctly installed, and suitable for the conditions. It will not fix bulk water, high crawl-space humidity, air leakage, missing vapor barrier, or undersized equipment by itself.

When should insulated ducts be replaced instead?

Consider replacement when ducts are crushed, torn, contaminated, wet through the liner, poorly sized, unsupported, or deteriorated across many sections. Do not pay to wrap material that cannot carry the required airflow.

Methodology

The estimator models accessible duct length, location, target R-value, old-wrap removal, sealing preparation, and condensation diagnosis. It separates insulation from physical repair and remediation so proposals can be compared on the same scope. Last updated September 29, 2026.