Fast, Reliable Spray Foam Insulation Across Windcrest
Most Windcrest homeowners with a 1960s or 1970s ranch are sitting on 3 to 4 inches of original blown fiberglass that’s compressed to R-7 or less after sixty years of 150°F attic heat cycling. Spray foam insulation in Windcrest typically runs $1.80 to $3.20 per board foot for open-cell and $2.80 to $4.50 for closed-cell, with a full attic retrofit on a 1,400-square-foot ranch ranging from $3,200 to $6,800 depending on whether we’re sealing the deck, encapsulating ductwork, or spraying the roof deck. We’re Envelope Insulation Co., independently owned and operated under The Haven Standard since 2016, and our crews serve Windcrest from our San Antonio dispatch office with same-day response to most calls. If your supply air is gaining 10°F or more before it reaches your vents, call (830) 549-6646 - we’ll give you a written price before any work starts and a blower-door number to prove the result.
Why Envelope Insulation Co. Is Windcrest’s Preferred Spray Foam Insulation Contractor
We’ve sealed and insulated over 9,000 homes since 2016, and Windcrest’s uniform mid-century build makes it one of the most predictable markets we serve. Every job begins with a written price - Haven Standard Clause 1 - and closes with a Documented Photo Record plus before-and-after blower-door readings on air-sealing work.
Our technicians know the Windcrest subdivision off Midcrown, the ranch homes along Walzem Road, and the low-pitched roofs near Windcrest Drive by their common failure patterns. Original 1-inch duct wrap on flex lines running through unconditioned attics, top plates never sealed during construction, rim joists left open to garage air - we find the same deficiencies house after house, which means our crews arrive with the right materials and no guesswork.
Calls are answered by a live person 24/7. Background-checked, uniformed technicians. A 365-Day Done Right Promise backed by written scope and written warranty delivered before anyone lifts a tool. And if you have a competing quote, bring it - we offer a Free Second Opinion on any written estimate.
Our Spray Foam Insulation Services in Windcrest
Closed-Cell Spray Foam
Closed-cell spray foam is our default recommendation for Windcrest’s shallow attic cavities and garage rim joists. At R-6.5 per inch, it hits code-compliant R-38 in under 6 inches of depth - critical when your roof pitch barely clears the top plates. We source closed-cell products from Demilec and Icynene, and we never spray over unsealed surfaces. On a 1962 ranch in the Windcrest subdivision off Midcrown, our tech found the original 1-inch-wrapped flex duct baking at 150°F+ against 3 inches of collapsed fiberglass, so we sealed the attic deck, encapsulated the ducts, and sprayed 2 inches of closed-cell foam on the roof deck - dropping the supply-air temperature gain from 12°F to 3°F on a 104°F afternoon. The homeowner walked away with blower-door readings, photos, and a written warranty.
Open-Cell Spray Foam
Open-cell runs $1.80 to $2.80 per board foot in the Windcrest market and works well for roof deck applications where vapor permeability matters. But we’re direct about the risk: open-cell applied directly over old, dusty blown insulation without air sealing the top plates lets humid Gulf air migrate through and condense on the foam underside. In Windcrest’s climate, that’s a mold liability. Our crews seal first - top plates, can lights, penetrations - then insulate. Always in that order. No exceptions.
Spray Foam Roof Deck
Windcrest’s slab-foundation ranch builds with ductwork in unconditioned attics create a compounding loss problem. Spraying the roof deck with closed-cell foam turns the attic into a semi-conditioned space, dropping ambient temperatures from 150°F to 85°F on peak summer days. This is often the most cost-effective retrofit for Windcrest homes where the HVAC system is already struggling. We check for active roof leaks before spraying - closed-cell over wet 1950s-70s sheathing traps moisture and causes rot. Our inspection is documented; you get the photos.
Rim Joist Spray Foam
Windcrest’s attached garages share a common flaw: rim joists left open to garage air, creating a thermal bypass that bleeds conditioned air into an unconditioned space. Closed-cell rim joist spray foam seals and insulates in one pass. Typical Windcrest garage rim joist jobs run $800 to $1,400 for a two-car bay. We remove degraded or pest-damaged old insulation before spraying - never foam over contamination.
Garage Ceiling Spray Foam
For homeowners converting garage space or running conditioned rooms above, garage ceiling spray foam addresses both thermal transfer and airborne infiltration. Windcrest’s 1960s construction rarely included any ceiling insulation here. We assess the floor system, check for plumbing penetrations, and deliver a written scope before work begins.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Before
AfterTrusted Brands We Install in Windcrest
We source spray foam materials from Icynene, Demilec, Owens Corning, and other major manufacturers - no proprietary lock-in, no house-brand substitutions. For Windcrest homeowners, this means we match the product to the application rather than forcing a one-size-fits-all approach. Demilec’s closed-cell formulations perform well in our high-humidity, high-heat climate zone. Icynene’s open-cell products carry strong track records for roof deck work where drying potential matters. We stock common formulations locally, so most Windcrest jobs start within a week of written approval, not after a multi-week material order.
Common Spray Foam Insulation Problems We See in Windcrest Homes
- Compressed original fiberglass performing at R-7 or less. Windcrest’s 3 to 4 inches of settled blown fiberglass from the 1960s-70s has degraded under decades of thermal cycling. Homeowners assume they have R-19; measurement shows R-7. The fix is removal, air sealing, and replacement with spray foam to current IECC standards.
- Open-cell foam installed over unsealed, dusty attic decks. We’ve corrected competitor jobs where humid Gulf air migrated through top plates and condensed against the foam. In Windcrest’s climate zone, air sealing is not optional - it’s a hard prerequisite under The Haven Standard.
- Closed-cell sprayed over active roof leaks on mid-century sheathing. Windcrest’s 150°F attic temperatures accelerate moisture damage when foam traps water against 1950s-70s plywood or board sheathing. Our pre-install inspection includes moisture mapping; you get the documentation.
- Uninsulated flex duct with 1-inch wrap running through 150°F attics. This is the hidden tax on nearly every Windcrest ranch. Spray foam on the roof deck or duct encapsulation with closed-cell solves it; either way, we measure the supply-air temperature gain before and after so you see the number.
Pricing for Spray Foam Insulation in Windcrest, TX
Here are the ranges we see on Windcrest jobs after delivering written prices since 2016:
| Application | Typical Range | Notes |
|---|---|---|
| Open-cell spray foam (attic deck) | $1.80 - $2.80 / board foot | Requires air sealing first; not for unsealed top plates |
| Closed-cell spray foam (attic, rim joist, garage) | $2.80 - $4.50 / board foot | Higher density, R-6.5/inch, moisture barrier |
| Full attic retrofit, 1,400 sq ft ranch | $3,200 - $6,800 | Includes removal, air sealing, spray foam to R-38 |
| Roof deck spray foam (closed-cell) | $4,500 - $8,200 | Turns attic semi-conditioned; includes leak inspection |
| Garage rim joist, two-car bay | $800 - $1,400 | Removes old insulation, seals and insulates |
| Duct encapsulation with closed-cell | $1,800 - $3,400 | Applied over existing flex duct in attic |
What moves the number: roof deck accessibility, active leak repair needs, old insulation removal volume, and whether we’re also encapsulating ductwork. Every Windcrest homeowner gets a written price before any work starts - Haven Standard Clause 1 - plus a Free Second Opinion if you have a competing quote. Call (830) 549-6646 to schedule.
We Also Serve Cities Near Windcrest
Our crews work throughout the San Antonio metro area, including Windcrest and nearby Seguin, New Braunfels, Cibolo, and Schertz. Dispatch and scheduling are coordinated from our San Antonio office; response times to these surrounding communities typically fall within the same service window as Windcrest proper. For spray foam insulation across the region, we apply the same Haven Standard: written price first, documented record last.
Serving Windcrest, TX - Our Local Coverage Area
We’re based in the Windcrest 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 - Spray Foam Insulation in Windcrest
No. We remove degraded fiberglass before spraying. Old blown insulation in Windcrest is typically compressed, dusty, and may harbor pest debris from decades of attic heat cycling. Our crew vacuums the attic deck clean, air seals top plates and penetrations, then applies spray foam to a clean substrate. You’ll receive before-and-after photos and blower-door readings. Call (830) 549-6646 for a written price - estimates are free.
Spray foam on the attic deck helps, but ductwork with 1-inch wrap in a 150°F attic is a separate loss point that compounds the problem. We often recommend duct encapsulation with closed-cell foam or a full roof deck spray to bring the attic into the conditioned envelope. On that 1962 ranch off Midcrown, roof deck foam dropped supply-air temperature gain from 12°F to 3°F. The right fix depends on your duct condition and HVAC age - we’ll assess both and give you a written scope with options.
Closed-cell for most Windcrest applications. The shallow cavity depth means you need maximum R-value per inch, and closed-cell’s R-6.5 delivers code compliance in under 6 inches. Open-cell works for roof decks where vapor permeability aids drying, but only after rigorous air sealing. We don’t recommend open-cell for rim joists or garage applications in our humid climate zone. Your written price will specify the product and why.
Yes. Garage rim joists in Windcrest often have degraded batt insulation, pest activity, or moisture staining from thermal bypass. We remove all existing material, clean the substrate, then apply closed-cell foam. The job includes a Documented Photo Record of the empty cavity and finished work. Typical two-car bay: $800 to $1,400. Written price before work starts.
Closed-cell spray foam on the roof deck typically drops Windcrest attic temperatures from 150°F+ to 80-90°F on peak summer days. The foam creates an air seal and thermal barrier at the roof line, moving the building envelope from the attic floor to the roof deck. Your ductwork now operates in a semi-conditioned space instead of a solar oven. We measure the before-and-after supply-air temperature gain so you see the performance change in degrees, not promises. Call (830) 549-6646 to schedule a free estimate with written pricing.
Ready to fix your Windcrest attic? Call Envelope Insulation Co. at (830) 549-6646. A live person answers 24/7. We’ll schedule a free inspection, deliver a written price before any work starts, and leave you with documented proof of the result - blower-door numbers, photos, and a 365-Day Done Right Promise backed by written warranty.
Written by Wes Okafor, Owner at Envelope Insulation Co., serving Windcrest and the San Antonio metro area under The Haven Standard since 2016.