Spray Foam Insulation in Dorchester, MA

Spray Foam Insulation in Dorchester means working on a neighborhood with deep roots and a lot of streetcar-era housing. Wikipedia describes Dorchester as covering more than 6 square miles, roughly the size of Cambridge. It was founded by Puritans in 1630, a few months before Boston itself, and was still mostly rural with about 12,000 people when Boston annexed it in 1870. The streetcar boom that followed brought waves of immigrants in the late 19th and early 20th centuries and the triple-deckers and two-families that still line its streets.

The triple-decker problem

A Dorchester triple-decker usually has a basement with a bare rim joist, three floors of plaster walls with empty bays, porches tied into the main frame and a low-slope roof with a shallow cavity. Air moves up through the building all winter. The fix works from both ends: closed-cell foam at the sill and rim, sealing and insulation at the roof cavity or top-floor ceiling, and dense-pack in the walls.

Victorians and singles

Dorchester also has Victorian single-family homes, especially on its hills. Those have tall walls, turrets, dormers and odd attic spaces. Balloon framing lets air rise inside the walls, so sealing the top and bottom of each bay matters as much as filling it.

Owners and tenants

Many Dorchester buildings are owner-occupied on one floor and rented on the others. Mass Save's assessment page lists paths for both landlords and renters in one- to four-unit buildings. If you hire us directly, we schedule floor by floor so tenants know when to expect us.

Barriers in older buildings

Older Dorchester houses often have knob-and-tube wiring somewhere in the walls, and some have vermiculite in the attic. City guidance says inactive knob-and-tube does not stop insulation and points income-verified owners to a barrier incentive of up to $7,000.

Costs

HomeGuide lists rim joist foam at $2,000 to $2,500 and dense-pack cellulose at $1.60 to $4.20 per square foot nationally. A three-unit building has more area than a single-family house, so we price each area separately and let you phase the work.

Porches and bays

Dorchester triple-deckers often have stacked front porches and bay windows that tie into the main frame. Where a porch roof meets the wall, and where a bay projects out over open air, the framing is usually open and uninsulated. Cold air travels from those spots into the floor and wall cavities of each unit. Sealing those junctions with foam is a small part of the job that fixes drafts tenants notice right away.

Get started

We walk the whole building and send a written quote by area and unit. Get a free estimate