OPEN CELL SPRAY FOAM FOR MULTIFAMILY BUILDINGSa
The best choice for sound control between units. Open-cell spray polyurethane foam expands to fill every irregular cavity completely, providing excellent air sealing and insulation simultaneously while dramatically reducing unit-to-unit sound transmission. A meaningful tenant satisfaction improvement that adds value beyond the energy savings.
COMPLETE CAVITY FILL WITH SOUND CONTROL
Open-cell spray polyurethane foam is a two-component foam that expands 100 times its liquid volume upon application, sealing and insulating in a single application. The "open cell" structure means individual foam cells are interconnected, which gives the material superior sound-dampening properties compared to closed-cell foam or any fiber insulation. It expands into and seals irregular cavities, around penetrations, and into geometric details that batt insulation cannot fill.
— WHY OPEN CELL
For multi-family buildings, the sound control benefit is significant. Tenant complaints about noise from neighboring units rank consistently among the top three reasons tenants do not renew leases. Open-cell foam between units reduces this complaint dramatically while delivering R-3.5 to R-3.8 per inch and acting as a partial air barrier. It is the right choice for interior partition walls, complex geometric cavities, and any assembly where comfort and acoustics both matter.
✓ R-3.5 to R-3.8 per inch installed thermal performance
✓ Reduces unit-to-unit sound transmission significantly
✓ Expands to fill irregular cavities completely
✓ Acts as a partial air barrier and insulator in one application
✓ Lower cost per board foot than closed-cell spray foam
✓ Best for interior walls, sound dampening between units, complex cavities
✓ Rebate eligible across applicable Illinois utility programs
Where We Install Open Cell Spray Foam
Open cell foam excels where complete cavity fill and sound dampening matter more than maximum R-value or moisture resistance. In multifamily buildings, that means interior spaces, complex geometries, and assemblies between units.
Interior Partition Walls
Between units in multifamily buildings. Open cell foam dramatically reduces unit-to-unit sound transmission. Tenants stop hearing neighbors. Lease renewals go up. The acoustic benefit alone often justifies the material choice.
Vaulted & Cathedral Ceilings
Sloped and irregular ceiling geometries that batt insulation cannot follow. Spray foam expands to fill every angle, joist bay, and structural detail completely, leaving no voids where convection currents can form.
Mechanical Chases
Vertical chases for plumbing, HVAC, and electrical run between floors and through walls. Spray foam seals around pipes and conduits at the same time it insulates, blocking the air pathways that batt insulation cannot.
Complex Framing
Older Chicago multifamily buildings often have irregular framing, blocked cavities, and unusual structural details. Open cell foam fills every irregularity completely, where pre-cut batts would leave voids and underperform.
Window & Door Penetrations
The gaps around window and door framing are one of the most common air leak points. Low-expanding open cell foam seals these penetrations without bowing the framing, and bonds permanently to the structure.
Floor Cavity Sound Dampening
Between floors in stacked multifamily units. Sealing the floor cavity with open cell foam reduces footstep noise and unit-to-unit sound transmission while providing thermal separation between conditioned spaces.
How Open Cell Foam Compares to Other Insulation Types
| Property | Open Cell Foam | Closed Cell Foam | Cellulose | Fiberglass Batt |
|---|---|---|---|---|
| R-Value per Inch | 3.5 - 3.8 | 6.0 - 7.0 | 3.2 - 3.8 | 2.2 - 2.7 |
| Air Sealing Ability | ||||
| Sound Dampening | ||||
| Cavity Fill Quality | ||||
| Moisture Resistance | ||||
| Typical Cost | Medium | Highest | Low - Medium | Lowest |
| Best For | Interior walls, sound dampening, complex cavities | Rim joists, crawl spaces, exterior walls | Attics, walls, retrofits | New construction |