Fast, Reliable Spray Foam Insulation Across North Hills
Spray foam insulation in North Hills typically runs $2.80 to $5.60 per board foot for open-cell, and $4.20 to $7.90 per board foot for closed-cell, with most attic applications falling between $2,400 and $7,500 depending on square footage and foam depth. Most jobs are completed same-day or next-day because we dispatch crews from our Van Nuys shop, about fifteen minutes from Sepulveda Boulevard. If your ranch home’s attic hits 150°F by noon and your AC never stops running, we can usually be out to you within 24 hours. Call (855) 382-3451 and we’ll tell you exactly what your roof deck needs before anyone climbs a ladder.

North Hills sits in the hottest corridor of the San Fernando Valley. That’s not marketing language. It’s the reason spray foam specs here look different than they do in Burbank or Thousand Oaks. The heat load drives everything. We’ve worked enough homes along Nordhoff, Plummer, and Hayvenhurst to know that the wrong foam in the wrong attic creates problems most contractors never see coming.
Why Thermal Insulation Co Is North Hills’s Preferred Spray Foam Insulation Company
We’re a dedicated insulation contractor. Not a generalist. Not a handyman who picked up a foam rig last spring. Thermal Insulation Co is led by Ruben Castellano, and insulation is the only trade we practice. That matters in North Hills because the housing stock here presents a very specific set of problems: 1950s and 1960s ranch homes with low-pitch roofs, original R-11 batts that have compressed to R-4 or worse, and attic cavities that get so hot the framing itself dries out and cracks over decades.
Homeowners in the 91343 and 91393 ZIP codes call us after failed attempts with other contractors. The usual story: someone sprayed open-cell foam on the roof deck, it shrank in the heat, and now there are gaps pulling conditioned air straight out of the house. We fix those. Ruben has walked more North Hills attics than most crews in the Valley, and he’ll tell you honestly whether spray foam is even the right call for your specific home, or whether a different method makes more sense.
Our proximity to North Hills means response times are short. We don’t treat this area as an outlying service territory. We stock materials for the housing types we know we’ll encounter here: closed-cell foam systems, air-sealing products, and radiant-barrier coatings sized for low-pitch attics.
Open Cell Spray Foam in North Hills
Open-cell spray foam in North Hills works well on vertical surfaces like rim joists, garage ceilings, and interior walls where the cavity doesn’t bake under direct roof heat. It expands aggressively, seals air leaks, and dampens sound. At roughly $2.80 to $5.60 per board foot, it’s the more affordable foam option when applied correctly to the right location. What we see too often, though, is open-cell foam applied to roof decks in North Hills attics where summer temperatures exceed 150°F, and that’s a failure waiting to happen: the foam shrinks, pulls away from the rafters, and you’re left with half-sealed cavities and wasted money.
Rim Joist and Garage Applications
For a North Hills ranch home, the rim joist is the wooden band running around the perimeter of the foundation, and it’s a major air leak point. Open-cell foam expands into the joist cavities and stops the stack effect that pulls hot attic air down through wall cavities. Garage ceilings also benefit, especially when the garage sits under a second-story addition or has a bedroom above.
When Open-Cell Fails in North Hills Heat
Ruben routinely sees open-cell foam that has shrunk on roof decks in 91343 and 91393 homes. The valleys between rafters become visible again, and conditioned air escapes through the gaps. If you have a low-pitch composition-shingle roof and a hot attic, open-cell on the roof deck is not a durable solution. We don’t sell it that way.
Spray Foam Insulation Contractors in North Hills
Spray foam insulation contractors in North Hills should know the difference between a roof deck application and a rim joist application, and many don’t. We do. Our crews handle open-cell and closed-cell systems from Icynene and Demilec, and we’re trained on the specific thermal and moisture conditions that define the San Fernando Valley. A typical closed-cell roof deck job on a North Hills ranch runs $4,500 to $7,500, while rim joist sealing on a standard 1,200-square-foot home usually lands between $1,800 and $3,200.
Closed-Cell for the Roof Deck
Closed-cell foam delivers about R-6.5 per inch, and more importantly, it resists moisture vapor and holds its shape at high temperatures. In a North Hills attic hitting 150°F, that stability is the difference between a sealed thermal envelope and a gap-riddled mess. We often pair it with a radiant-barrier coating on the rafters to reflect heat before it ever penetrates the foam.

Radiant Barrier and Air Sealing Combination
The most effective upgrade for a 1960s North Hills home is rarely just foam. It’s foam plus air sealing at top plates, electrical penetrations, and recessed light cans. That combination addresses the conductive heat gain through the roof deck and the convective air leaks that pull hot outside air into your living space all summer.
Trusted Brands We Service in North Hills
We carry Icynene and Demilec spray foam systems because they hold up under sustained heat better than cheaper formulations, and we install them correctly for the application. For North Hills homeowners who need batt or blown-in work alongside their foam project, we stock Owens Corning, Johns Manville, and Knauf fiberglass, plus Rockwool mineral wool for fire-resistance applications near furnaces and water heaters. GreenFiber cellulose is available for homeowners who want a recycled-content option in walls or attic floors. Eight brands, three installation methods, one trade. We stock what we install, which means faster turnaround for North Hills jobs.
Common Spray Foam Insulation Problems We See in North Hills Homes
- Open-cell foam shrunk on the roof deck. In attics that exceed 150°F, open-cell foam pulls away from rafters within a few years, creating gaps that leak air straight through the ceiling. We remove the failed material and respec with closed-cell foam and a radiant barrier.
- Compressed or rodent-contaminated original batts. The 1950s and 1960s ranch homes in 91343 and 91393 often still have their original R-11 fiberglass, which by now is compacted, dusty, and sometimes full of rodent droppings. Spraying foam over that mess traps moisture and fails to seal the air leaks you’re trying to fix.
- Shingle overheating from improper foam application. On low-pitch composition-shingle roofs, applying foam directly to the underside of the deck without proper thermal planning can drive shingle temperatures up and shorten roof life. We assess the roof assembly before we ever fire up the rig.
- Bare joist cavities visible at the attic hatch. Pop the hatch on a mid-century North Hills home and you’ll often see exposed ceiling drywall below the joists, meaning there’s no insulation at all in some cavities. That’s a heat sieve, and it’s one of the first things we address when we scope a job.
Pricing for Spray Foam Insulation in North Hills, CA
Open-cell spray foam in North Hills runs $2.80 to $5.60 per board foot. Closed-cell foam runs $4.20 to $7.90 per board foot. A full roof deck application with 3 inches of closed-cell on a typical 1,200-square-foot ranch runs $4,500 to $7,500. Rim joist sealing typically lands between $1,800 and $3,200. Garage ceiling foam runs $900 to $2,200. What drives the cost: how much prep work is needed (failed insulation removal, rodent cleanup, air sealing), access difficulty in low-pitch attics, and whether we’re adding a radiant barrier. Call (855) 382-3451 for an exact quote. Estimates are free, and we’ll show you the numbers on paper before you commit.
We Also Serve Cities Near North Hills
From our Van Nuys shop, we run crews to Northridge, Van Nuys, Valley Glen, and San Fernando on the same schedule we serve North Hills. If you’re just outside the 91343 or 91393 ZIP codes, call us and we’ll confirm same-week availability. Our Spray Foam Insulation team covers the entire central and western San Fernando Valley.
Serving North Hills, CA — Our Local Coverage Area
We’re based in the North Hills area and know this community well. Use the map below to see our service coverage — if you’re nearby, we can almost certainly help.
FAQs About Spray Foam Insulation in North Hills
Yes, but only closed-cell foam. Open-cell foam degrades and shrinks at sustained 150°F heat, while closed-cell holds its shape and seals the roof deck properly. We recommend 3 inches of closed-cell with a radiant-barrier coating on low-pitch North Hills roofs. Call (855) 382-3451 for a roof deck assessment and firm quote.
No, and we won’t. Spraying foam over failed, rodent-contaminated fiberglass traps moisture, smells, and air leaks. We remove the old batts, air-seal the top plates and penetrations, then apply the correct foam spec. The removal step adds to the project cost but it’s the only way to get the performance you’re paying for. Call us for a removal and re-insulation quote.
Closed-cell spray foam seals the small entry points rodents use to enter: rim joist gaps, plumbing penetrations, and top plate seams. While foam isn’t a rodent repellent, it closes the routes they travel, and we remove contaminated insulation before sealing. A sealed attic stays cleaner and less attractive to pests.
Yes, when applied to the right surfaces. Mid-century stucco homes in 91343 typically have accessible attics and exposed rim joists, both good candidates for foam. We focus on the roof deck, rim joist, and garage ceiling rather than wall cavities, which are hard to reach without major demo. Call (855) 382-3451 and we’ll scope the specific home.
A North Hills ranch that currently has compressed R-11 batts typically jumps to R-19 or R-20 at the roof deck with 3 inches of closed-cell foam, and the air-sealing work alone often reduces air leakage by 30% or more. The combination addresses both conductive and convective heat gain, which is the real problem in 150°F attics.
Call Thermal Insulation Co for Spray Foam in North Hills
If your attic runs 150°F in summer and your AC never stops running, we’ll scope it honestly and tell you what’s actually causing the problem. Ruben Castellano and our crews know North Hills housing stock: the low-pitch roofs, the failed 1960s batts, the bare joist cavities. Call (855) 382-3451 for a free estimate, and we’ll walk your attic before we quote a single number.
Written by Ruben Castellano, Owner at Thermal Insulation Co, serving North Hills and the broader San Fernando Valley from our Van Nuys shop.