Fast, Reliable Spray Foam Insulation Across Murrieta
Spray foam insulation in Murrieta typically costs $3.50 to $7.50 per square foot for open-cell and $4.50 to $9.00 per square foot for closed-cell, with most attic applications running $4,200 to $11,800 depending on square footage. A full two-story home retrofit off Clinton Keith Road or Winchester Road usually lands between $7,500 and $16,000. Thermal Insulation Co installs both open-cell and closed-cell foam from Icynene and Demilec, and we stock the materials to handle Murrieta’s specific problem: those 1990s and 2000s tract homes where the original attic batts have compressed and the upstairs rooms bake every summer.

We’re a dedicated insulation contractor with crews that know the Murrieta housing stock the way a local would. When you call (855) 382-3451, you’ll reach a scheduler who can talk about specific neighborhoods off Murrieta Hot Springs Road or the older streets around Historic Downtown without needing a script. We run free estimates throughout 92562, 92563, and 92564, and we can typically get a technician to your house within two business days of the initial call, faster if you’re dealing with an active moisture issue or a spike in your SCE bill during the first heat wave.
Why Thermal Insulation Co Is Murrieta’s Preferred Spray Foam Insulation Company
We’re not a generalist contractor who picked up a foam rig last year. Insulation is our only trade, and our work in Murrieta has taught us the specific failure patterns of the city’s master-planned subdivisions. The original R-19 attic batts in homes off Clinton Keith Road compress under years of 100°F+ attic heat, and the R-11 wall batts in 1980s builds near downtown were never enough for the inland valley summers. Knowing this changes how we quote a job, which is why our estimates for Murrieta homes reference the construction era of the specific neighborhood.
Ruben Castellano leads our crew, and under his direction we’ve built a reputation in southwest Riverside County for matching the foam system to the home rather than pushing whatever is on the truck. We carry both open-cell Icynene for interiors where sound control matters and closed-cell Demilec where moisture resistance and structural rigidity are priorities. That dual-brand capability means you’re not forced into a single product line. Homeowners in 92563 who’ve had us out on the first 100°F day of the year tend to tell their neighbors, which is how most of our Murrieta work arrives.
Spray Foam Attic Insulation in Murrieta
Spray foam attic insulation in Murrieta is the single most effective retrofit for those two-story stucco homes where upstairs bedrooms run 10 to 15°F hotter than the living room every July. The job involves sealing the attic deck from the inside, covering the roofline rather than the floor, and transforming the attic from a passive hotbox into a conditioned space. In Murrieta’s tract housing off Winchester Road and Clinton Keith Road, the most common application is open-cell or closed-cell foam sprayed across the entire roof deck after the old compressed batts are removed. Closed-cell adds structural strength and an air-permeance barrier that open-cell can’t match, and we recommend it in most Murrieta attics because the summer temperature delta is severe enough to warrant the extra cost. Attic deck applications here typically run $5,800 to $12,400 depending on the roofline area and whether you have deep overhangs or a low-pitch tile roof that limits access.
Whole-Attic Sealing, Not Just More Batts
Most Murrieta homes don’t just need more insulation. They need the gaps around recessed can lights, HVAC plenums, and framing penetrations sealed. Those gaps are radiant heat chimneys during the first 100°F week of summer. We find them on nearly every 1990s and 2000s build we open up in this city.
When the Original R-19 Has Failed
If your attic batts measure 6 inches thick or less, they’ve compressed to roughly R-11 or lower. Foam replaces them with a continuous air and thermal barrier. We also handle the transition where the attic floor meets the top plates of exterior walls, a spot fiberglass never sealed well in Murrieta’s master-planned builds.
Spray Foam Wall Insulation in Murrieta
Spray foam wall insulation in Murrieta is a common retrofit for older neighborhoods near Historic Downtown and parts of 92562 where the original wall batts were never upgraded. The work requires opening wall cavities, removing any failing batt material, and spraying foam directly against the interior face of the exterior sheathing. In Murrieta’s stucco-clad wood-frame construction, the critical step is removing the old R-11 or R-13 batts before spraying. Applying foam over them traps moisture against the wood and stucco, especially after a Santa Ana wind-driven rain event when sideways water pushes through hairline stucco cracks. We remove the old material first, inspect the sheathing for dry rot or termite damage, and only then spray. Wall applications here generally run $2,800 to $7,200 for a partial retrofit up to $12,000 to $22,000 for a full two-story re-insulation, with closed-cell Demilec on the higher end due to its higher R-value per inch and moisture-blocking performance.
Open-Cell for Interior Walls
Where sound transfer between bedrooms or from the garage matters, open-cell Icynene does double duty. It deadens noise and insulates without the rigid, dense feel of closed-cell. We recommend it for interior partition walls and bonus rooms over garages.
Closed-Cell for Exterior Walls
For exterior walls in Murrieta’s fire-prone zones, closed-cell Demilec is the better choice. Its density helps block air infiltration and adds a measure of rigidity to the wall assembly. It also doesn’t absorb water, which matters when the Santa Anas drive rain into stucco.

Trusted Brands We Service in Murrieta
We install and service foam from two major manufacturers: Icynene for open-cell applications where air sealing and acoustics matter most, and Demilec for closed-cell jobs requiring moisture resistance and structural reinforcement. That’s a meaningful distinction in Murrieta, because the two foams solve different problems. Beyond spray foam, our product portfolio includes Owens Corning and Johns Manville batt and blown-in systems for cases where foam isn’t the right call, along with Rockwool mineral wool for fire-resistant wall assemblies in Murrieta’s high-fire-zone neighborhoods. Since we stock materials locally for Murrieta jobs, turnaround from estimate to installation is faster than a contractor ordering foam from out of state.
Common Spray Foam Insulation Problems We See in Murrieta Homes
- Compressed attic batts leaving radiant heat chimneys. Original R-19 batts in 1990s and 2000s tract homes off Clinton Keith and Winchester Road compress to R-11 or less. Gaps around recessed can lights and HVAC plenums then funnel 140°F attic air into upstairs bedrooms.
- Foam sprayed over old wall batts, trapping moisture. Some retrofit jobs in 1980s stucco homes near downtown skipped batt removal. After Santa Ana rain events, moisture wicks into the wood frame and the stucco interior face, creating mold and dry rot risk behind the foam.
- Closed-cell foam applied too thin on attic decks. Under 2 inches of closed-cell on the roofline doesn’t stop thermal bridging through the wood rafters. The rafters still conduct heat straight down into the ceiling drywall, so upstairs rooms stay hot even after the job.
- Ignoring the attic-hatch and top-plate seams. Spray foam works as a system, not a patch. We see Murrieta homes where the attic deck was foamed but the pull-down stair or hatch was left unsealed, leaking conditioned air and undermining the whole air barrier.
Pricing for Spray Foam Insulation in Murrieta, CA
Open-cell spray foam in Murrieta runs $3.50 to $7.50 per square foot of surface area sprayed. Closed-cell runs $4.50 to $9.00 per square foot. A typical attic deck application in a 2,400-square-foot home off Clinton Keith Road costs $5,800 to $12,400; a full wall retrofit on the same home runs $12,000 to $22,000. What moves the number? The roofline area and pitch, whether we’re removing old batts (usually yes), the foam system you choose, and the access conditions around low-pitch tile roofs common in Murrieta subdivisions. Estimates are free, and we walk you through the specific line items before you commit. Call (855) 382-3451 and we’ll schedule a measurement visit.
We Also Serve Cities Near Murrieta
Our crews cover the surrounding southwest Riverside County cities, including Murrieta Hot Springs, Wildomar, Temecula, and Sedco Hills. If you’re just outside the Murrieta city line but still fighting the same inland valley heat, give us a call. We schedule routes through Spray Foam Insulation service areas across the region, so timing is often shorter than you’d expect.
Serving Murrieta, CA — Our Local Coverage Area
We’re based in the Murrieta 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 Murrieta
Yes. Spray foam seals the attic deck and converts the attic from a passive hotbox into a conditioned buffer, which directly reduces the heat load that radiates down into upstairs bedrooms during Murrieta’s 100°F+ days. It also cuts air leakage that Santa Ana winds force through ridge vents and gable ends. Closed-cell foam on the attic deck adds a structural barrier against wind-driven ember intrusion, which matters in Murrieta’s high-fire-zone areas. Call (855) 382-3451 for a heat-loss assessment.
Yes, in almost every case. Spraying foam over the original builder-grade R-11 or R-13 batts in Murrieta’s stucco-clad homes traps moisture against the wood frame and the back of the stucco, especially after Santa Ana rain events. We remove the old batts, inspect the sheathing, and only then spray. It’s the only way the foam bonds correctly to the exterior sheathing.
Closed-cell spray foam can reduce air movement through the wall and roof assembly, which slows the spread of flame and limits ember intrusion through gaps. It is not a fireproofing system on its own, but combined with proper fire-rated assemblies and ember-resistant vents, it supports the ignition-resistant construction Murrieta homeowners are asking for. We also install Rockwool mineral wool for specific fire-resistant wall applications.
In Murrieta’s 1990s and 2000s tract homes, the original attic batts have compressed and gaps around recessed can lights and HVAC plenums act as radiant heat chimneys. During the first 100°F week of summer, those spots push attic air into the upstairs bedrooms, creating the 10 to 15°F temperature difference you’re feeling. Sealing those penetrations and spraying the attic deck fixes the stack effect and brings the upstairs within a degree or two of the downstairs setpoint.
It depends on the home’s framing and current insulation condition, but in most 1970s Murrieta homes near Historic Downtown, the wall cavities are already under-insulated with degraded R-11 batts. Adding more batts on top doesn’t fix the air leakage or the moisture issues. Spray foam, properly installed after batt removal, addresses both thermal and air-barrier performance at once. We’ll tell you if batts alone can do the job, but in our experience with Murrieta’s older stock near downtown, foam is the more durable fix.
Written by Ruben Castellano, Owner at Thermal Insulation Co, serving Murrieta and surrounding Riverside County cities.
Ready to see what’s actually happening in your attic or walls? Call Thermal Insulation Co at (855) 382-3451 for a free estimate. We’ll measure, diagnose the specific failure patterns in your Murrieta home, and recommend the right foam system for your construction era and performance goals.