Building materials/Density-rated
Insulation freight class and NMFC guide
Insulation is extremely light for its cube, so it usually lands in the most expensive density tiers. Compression and packaging are the difference between a full load and a costly one.
Reviewed November 11, 2026 · Reference 2026.11 · Estimate, not a classification
At a glance
DensityClassification basis
Density-rated
Typical packed density
0.7–2 lb/ft³
Planning estimate
Density-rated span
Class 250–400
Reclass risk
Medium
Density can move with packaging, case count, or pallet pattern, so a second measurement may land in another band.
Handling flags
Density-based estimate. Confirm the NMFC item, the packaging form, and any density subprovision before booking.
What drives the class
The density story behind insulation.
Insulation is a cube problem more than a weight problem. Loose fiberglass batts trap air, so a full trailer of insulation can weigh very little. Compressing the product or packing it tightly raises density and can move the shipment into a cheaper tier. Foam board and mineral wool are denser than loose batts, so do not use one range for every insulation product. Measure the packaged unit, not the nominal R-value.
Density-rated. Insulation is generally density-rated. The product is mostly air, so small packaging changes move the class quickly.
Density thresholds
Where the estimate sits on the 2025 scale.
The highlighted rows are the classes touched by the endpoints of the typical density estimate. A single measured density returns one class; the span is a planning range. The scale is effective July 19, 2025.
| Density band | Class | Estimate |
|---|---|---|
| 50 or more lb/ft³ | 50 | Reference |
| 35 to under 50 lb/ft³ | 55 | Reference |
| 30 to under 35 lb/ft³ | 60 | Reference |
| 22.5 to under 30 lb/ft³ | 65 | Reference |
| 15 to under 22.5 lb/ft³ | 70 | Reference |
| 12 to under 15 lb/ft³ | 85 | Reference |
| 10 to under 12 lb/ft³ | 92.5 | Reference |
| 8 to under 10 lb/ft³ | 100 | Reference |
| 6 to under 8 lb/ft³ | 125 | Reference |
| 4 to under 6 lb/ft³ | 175 | Reference |
| 2 to under 4 lb/ft³ | 250 | Typical span |
| 1 to under 2 lb/ft³ | 300 | Typical span |
| 0 to under 1 lb/ft³ | 400 | Typical span |
Measure it right
The handling unit is the shipment.
Carriers measure what is tendered, not the product inside the box. Use the pallet, crate, or bundle as the handling unit and include everything that travels with it.
- Measure the packaged bag or bundle at its widest point; compressed packages can bulge.
- Use gross weight with the bag, wrap, and pallet.
- Measure loose-fill and board insulation separately; their densities are different.
The formula
cube = L × W × H ÷ 1,728
density = gross lb ÷ cubeRound for display only. Compare the unrounded density to the scale boundary.
Oversize / bulky
Long, tall, or irregular handling units can affect stowability and linear feet.
Moisture-sensitive
Needs wrap, desiccant, or a dry loading position to avoid a damage claim.
Pack it for the rating
Packaging changes the cube before it changes the class.
- Compression helps density but can damage some products; follow the manufacturer limits.
- Keep insulation dry and off the trailer floor; moisture destroys R-value and creates a claim.
Don't confuse it with
Adjacent items, different answers.
The most expensive classification mistake is usually a description that sounds close but is not the item. Check these before you copy a description from another shipment.
Foam products
Acoustic panels
Reflective barriers
Before you book
Make the rating defensible.
- Confirm the item for the specific insulation type.
- Ask whether the carrier rates the packaged unit or the loose product.
- Photograph the package and pallet before pickup.
BOL description template
Starting pointInsulation, [type], packaged, [quantity] bags or bundles, [gross weight] lb gross, [length x width x height] in per handling unit.
Add the confirmed NMFC item number before you tender the shipment. The template describes the freight; it is not a classification.
Common questions
Insulation and the 2025 scale.
How are insulation classified for LTL freight?
At an estimated packed density of 0.7–2 lb/ft³, the 2025 density scale spans Class 250–400. That is a planning span derived from the endpoints of the density estimate, not a promise that every shipment lands in every class. The NMFC item and the shipment as tendered control the final class.
What is the classification basis for insulation?
Density-rated. Insulation is generally density-rated. The product is mostly air, so small packaging changes move the class quickly.
How do I confirm the NMFC item for insulation?
Confirm the item for the specific insulation type. Ask whether the carrier rates the packaged unit or the loose product. Photograph the package and pallet before pickup. Confirm the current item in ClassIT+ or with the carrier before booking.
Related commodities
Keep the comparison close.
Plastics & chemicals
Foam products
Foam is one of the lightest freight commodities. Density depends almost entirely on compression and packaging, and the class can move several tiers with a tighter bundle.
Class 250–300Building materials
Drywall
Drywall is heavy, brittle, and usually shipped in large flat units. Density is high and stable, so the class is rarely a surprise — but damage and handling are.
Class 50–55Building materials
Lumber
Lumber is dense and stable, so density is rarely the hard part. The classification question is usually the species, grade, treatment, and whether the load ships as loose boards, a bundle, or a unit.
Class 55–65Building materials
Plywood
Plywood is dense and ships in flat, stackable units. Density is stable, but the number of sheets per unit and the way the unit is banded can change the measured cube.
Class 55–60Sources & limits
What this page is, and what it is not.
This is an independent planning reference, not the NMFC and not a carrier classification. The typical density is an estimate. The class span is derived from the 2025 density scale. The NMFC item, the carrier tariff, and the shipment as tendered control the final rating.
Reviewed November 11, 2026 · Reference 2026.11
- NMFTA — National Motor Freight Classification
The official classification system, its 18 classes, and the role of the NMFC item.
- NMFTA — 2025 NMFC changes
The July 19, 2025 effective date and the density-scale restructuring.
- NMFTA — ClassIT+
The licensed lookup for current NMFC item numbers and classification text.
- FedEx Freight — freight class calculator
Carrier class and density reference used to sanity-check the ranges.
Next step
Measure the load, then check the class.
Use the freight class calculator for a measured density, the pallet calculator for the finished handling unit, and the chart for the full 2025 reference.