Cellulose Insulation in Washington, DC

Dense-pack cellulose is our highest-ROI move for a Washington, DC row house with original plaster-and-lath walls. We bore 2-inch access holes into the wall cavity from the interior or the exterior brick, blow recycled-paper insulation in at high density (3.5+ lbs per cubic foot), and patch the holes invisibly. The wall stays vapor-open — critical for old DC brick that needs to dry inward — while gaining R-13 to R-15 of thermal performance and a major reduction in air infiltration. For attics, blown-in loose-fill cellulose at R-49 is the budget-friendly path to code-compliance.

Why Cellulose Wins for DC Historic Homes

Pre-1940 DC row houses were built without insulation in the wall cavities. Adding closed-cell spray foam to those walls is risky because the brick exterior needs to dry — trapping moisture between vapor-impermeable foam and the masonry can cause spalling and freeze-thaw damage over a decade. Dense-pack cellulose solves this by being vapor-open: water vapor moves freely through the assembly, the brick keeps drying, and you still get the insulation and air-sealing benefits. The Historic Preservation Office reviewers we work with regularly approve dense-pack cellulose as a preservation-friendly upgrade.

Cellulose is also fire-treated with borate to a Class A fire rating, naturally pest- and mold-resistant, and made from 80%+ post-consumer recycled paper — a strong story for the LEED-certified gut renovations common in DC.

Where We Use Cellulose vs. Other Materials

Pre-1940 row house walls (Capitol Hill, Georgetown, Adams Morgan, Mount Pleasant): Dense-pack cellulose, almost always. Vented attics: Blown-in loose-fill cellulose at R-49 is half the cost of foam and performs identically when the attic stays vented. Cathedral ceilings: Dense-pack between the rafters with proper baffling for ventilation. New construction: Spray foam or fiberglass usually wins on speed; we recommend cellulose for clients prioritizing recycled content. Basements and crawl spaces: Closed-cell spray foam — never cellulose, because cellulose can wick moisture if the wall ever gets wet.

Our Process, Run From Our Falls Church Shop

DMV Foam is headquartered in Falls Church — about 25 minutes from anywhere in DC. Every project begins with a walkthrough to confirm wall construction, access, and target areas. We protect floors and finishes (especially important for original DC hardwood and historic plaster), drill the smallest possible access holes, install to the right density so the material stays put for the life of the building, and patch every hole flush. We work weekly across Capitol Hill, Columbia Heights, Georgetown, Adams Morgan, Dupont Circle, and Mount Pleasant, and we coordinate with HPO submissions for any project that needs them.