Core-Fill
Insulation
Foam-in-place insulation for concrete block cores and masonry cavities. Injected through small holes in the mortar joints, set in about twenty seconds, no demolition.
The block insulation that goes in
after the wall is up.
Core-Fill 500 is an amino-plast foam insulation manufactured by Tailored Chemical Products, Inc. of Hickory, North Carolina. It is injected into the open cores of concrete masonry units and into masonry cavities, where it expands to fill voids and sets in roughly twenty seconds under typical conditions.
Bahl installs Core-Fill in new masonry construction and as a retrofit in existing block walls: schools, churches, warehouses, precast hollow-core panels and commercial buildings where the wall is already standing and the energy bill says it is uninsulated.
Pending confirmation (decision 1.2): this page and its eleven blog posts assume Bahl sells and self-performs Core-Fill. New page, no existing copy to keep.
What Core-Fill does, and what it does not do
Block density moves the wall R-value more than the foam does. Same 8-inch unit, same foam: R-8.58 in 85 pcf lightweight block versus R-4.08 in 135 pcf normal-weight block. That 2.1x swing comes from the block, which is why manufacturer construction tables read high.
Core-Fill is a two-component amino-plast foam: resin plus a catalyst and foaming surfactant, mixed at the gun and injected into the cores. It fills the voids, it does not carry load, and it does not raise the fire rating of the wall. Those limits matter as much as the R-value.
Wall R-values that account for thermal bridging through the block webs
| Unit | 85 pcf | 95 pcf | 105 pcf | 115 pcf | 125 pcf | 135 pcf |
|---|---|---|---|---|---|---|
| 6-inch foamed cores | R-6.38 | R-5.54 | R-4.80 | R-4.17 | R-3.63 | R-3.16 |
| 8-inch foamed cores | R-8.58 | R-7.40 | R-6.38 | R-5.49 | R-4.73 | R-4.08 |
| 10-inch foamed cores | R-10.47 | R-8.98 | R-7.69 | R-6.57 | R-5.62 | R-4.82 |
| 12-inch foamed cores | R-12.99 | R-11.10 | R-9.47 | R-8.07 | R-6.87 | R-5.86 |
Source: CMHA (formerly NCMA) TEK 06-02C, Table 2, series-parallel method. For compliance, point at the adopted energy code or ASHRAE 90.1 Appendix A, never at a manufacturer table. Foam R-value: R-4.5 per inch at 74F mean, R-4.9 at 32F mean, ASTM C518.
Standing limitations, stated on every page
- Not for ceiling or attic applications; not for overhead work.
- Will not support compressive loads; not for flotation.
- Not above 190F sustained; not underground as a vapor barrier.
- Does not raise the fire rating of a concrete masonry unit. If the wall needs a rating, that is a different scope.
Pricing a scope?
Send the drawings and the spec section. We return a number, not a range.
The block sets the R-value.
The foam finishes it.
Density is the variable nobody prices. A lightweight 85 pcf block with foamed cores insulates twice as well as a normal-weight 135 pcf block with the same foam. We say that on the bid so the number is real.
How we install Core-Fill
Survey
Block type, density, wall height and existing penetrations mapped; injection pattern set.
Drill
Small holes in the mortar joints on the injection pattern; no demolition.
Inject
Foam placed core by core from the bottom up, set in about twenty seconds.
Verify fill
Overflow at the next hole up confirms the core is full; voids re-shot.
Patch and document
Holes patched to match; coverage map and batch records handed over.
Contact Us
Call, email, or send the drawings through the form. All three land in the same place, and Ross reads them.
Request a Core-Fill bid
Core-Fill insulation by state
Austin, Dallas-Fort Worth, Houston, San Antonio, Lubbock
Core-Fill insulation in Texas →Oklahoma City, Tulsa
Core-Fill insulation in Oklahoma →Wichita, Kansas City metro, Hays
Core-Fill insulation in Kansas →Phoenix, Tucson
Core-Fill insulation in Arizona →Minneapolis, St. Paul, Rochester, Duluth, Brainerd, Walker, Bemidji
Core-Fill insulation in Minnesota →Milwaukee, Madison, Green Bay, Superior
Core-Fill insulation in Wisconsin →Core-Fill FAQ
Does Core-Fill raise the fire rating of my block wall?
No. The manufacturer states it is not intended and should never be used to increase the fire rating of a concrete masonry unit. It insulates; it does not rate.
Can it go in an existing building?
Yes. Retrofit of standing CMU walls is one of the four applications the manufacturer lists, alongside block insulation, masonry cavity fill and precast hollow-core panels.
What R-value will my wall have?
It depends on the block density more than the foam. The TEK 06-02C table above is the honest answer; the manufacturer construction table overstates it because it ignores the webs.
Is there an ICC-ES report?
None could be located as of August 2026, so we do not cite one.
What kinds of buildings use Core-Fill?
Anything built out of block. Schools and gyms, churches, fire stations, warehouses and shops, correctional and municipal buildings, agricultural structures, and precast hollow-core panels. New masonry and standing walls both.
How disruptive is it in an existing building?
Small injection holes go in the mortar joints and get patched to match. No demolition, no wall opened up, no interior finish removed. Most retrofits happen from the exterior while the building stays in use.
Does it settle over time?
It cures in place as a rigid cellular foam rather than sitting loose in the cavity, so it does not slump the way poured or blown loose fill can. That is most of the reason it gets specified for retrofit.
How much wall can you fill in a day?
Enough that it is rarely the schedule driver. The pour is fast; access, staging and weather are what set the duration. We give a real production rate with the bid once we see elevations.
From the Bahl library
Core-Fill 500 masonry insulation: the guide
Read the guide →
Core-Fill installation in concrete block walls
Read the guide →
CMU retrofit with Core-Fill 500 in existing buildings
Read the guide →
Rigid foam board vs Core-Fill 500 in the masonry cavity
Read the guide →This page describes Bahl Fireproofing's scope of work and general code context. Requirements, adopted code editions and inspection procedures vary by jurisdiction and project; confirm them with your licensed architect or engineer and the authority having jurisdiction. Nothing here is a warranty of a building's compliance or a substitute for the approved construction documents.