Fast, Reliable Spray Foam Insulation Across Redwood
Spray foam insulation in Redwood, TX typically runs $1.80-$3.20 per board foot for open-cell and $3.50-$5.50 for closed-cell, with most ranch houses and detached shops needing 2,000-5,000 board feet for a full attic or roof deck. We’re Envelope Insulation Co., independently owned and operated under The Haven Standard since 2016, and our crews serve Redwood from our Dallas-Fort Worth dispatch office with self-sufficient rigs built for the longer county-road drives. Call (737) 337-8049 for a written price before any work starts.
Redwood’s unincorporated Gonzales County acreage properties aren’t like jobs inside San Marcos or Seguin city limits. Your shop might sit twenty minutes off County Road 445, your ranch house might be pier-and-beam with belly boards exposed to ground moisture, and your attic might hit 150°F in July. That distance and those conditions change how we spec the foam, how we load the rig, and how we plan the day. We don’t make return trips because we forgot a heated hose or ran low on resin.
Why Topside Attic Insulation San Marcos Is Redwood’s Preferred Spray Foam Insulation Company
We’ve sealed and insulated more than 9,000 homes since 2016, and a growing share of those jobs are in Gonzales County’s rural stretches - Redwood, the county roads around it, and the acreage properties where city-code insulation never applied. Our Redwood customers find us through referrals from San Marcos and Lockhart homeowners we’ve already worked with, and they tend to call after reading our three-star reviews as carefully as our five-star ones. That scrutiny doesn’t bother us. We publish before-and-after blower-door numbers on every applicable job so you can verify the performance change yourself.
Response time to Redwood runs same-day to next-day depending on rig routing from our Dallas-Fort Worth office, but we answer calls 24/7 with a live person - no voicemail loops, no callback windows measured in business days. When we schedule your job, you get a named technician and a text when they’re on the way. Under Haven Standard: Arrive on schedule.
We know Redwood’s housing stock. Older farmhouses with zero wall insulation. Modest ranch-style homes from the mid-20th century with compressed fiberglass batts that humidity has degraded. Detached metal shops with open-gable roof decks that turn into solar ovens. Pier-and-beam foundations with crawl spaces that breathe ground moisture. We moisture-check every rim and belly board before we spray, and we meter foam thickness at every rafter bay instead of eyeballing it.
Our Spray Foam Insulation Services in Redwood

Closed-Cell Spray Foam
Closed-cell spray foam in Redwood runs $3.50-$5.50 per board foot and delivers R-6.5 per inch with a vapor-closed barrier. On Redwood’s acreage properties, we spec this heavier than city jobs because your detached shop or barn faces unbroken sun exposure and the kind of wind-driven rain that finds every gap. After Winter Storm Uri in 2021, Gonzales County homeowners learned fast that thin or missing insulation means frozen pipes. Two inches of closed-cell on a shop roof deck or rim joist gives you both summer radiant heat blocking and winter cold-air infiltration resistance. We sprayed two inches of closed-cell foam on the underside of an open-gable roof deck on a metal shop on County Road 445 just outside Redwood, after the homeowner reported his August shop thermometer pegged 154°F and his window AC couldn’t touch it. We closed the rim joist and the wall-to-roof transition in the same trip, and on the follow-up call he said the shop now holds under 80°F with the same unit running half as long.

Spray Foam Roof Deck
Spray foam applied directly to the roof deck - the underside of your roof sheathing - turns your attic into a conditioned space instead of a 150°F convection oven. In Redwood, where attics regularly exceed that temperature for months straight, this is often the right move for ranch houses with HVAC ducts running through the attic. Open-cell foam at $1.80-$2.80 per board foot works here at 5.5-6.5 inches depth for an R-38 assembly. But on detached shops with metal roofing, we typically spec closed-cell for its structural adhesion and vapor closure. The key on Redwood acreage jobs: we plan for the full depth in one pass, because a return trip costs us two hours of county-road driving.

Rim Joist Spray Foam
The rim joist - the perimeter band where your floor framing meets the foundation - is the leakiest part of most pier-and-beam houses. In Redwood, where pier-and-beam construction is common and ground moisture is persistent, an unsealed rim joist pulls humid air into your floor cavity year-round. Closed-cell rim joist spray foam in Redwood typically runs $800-$1,400 for a full perimeter treatment on a modest ranch house. We moisture-check every rim and belly board before we spray, because foam applied over damp wood traps that moisture and pops off within a season. This is non-negotiable on old Gonzales County ranch houses where the crawl space dirt might never fully dry.

Open-Cell Spray Foam
Open-cell spray foam at $1.80-$3.20 per board foot gives you R-3.6 per inch and vapor permeability, which matters in certain Redwood attic assemblies where you want the roof deck to dry to the interior. We use this in conditioned attics where the assembly is designed to manage moisture movement, not in crawl spaces or against ground-contact surfaces. For Redwood’s typical ranch house attic, 5.5-7 inches of open-cell on the roof deck achieves code R-38 with a lighter material load than closed-cell. We source open-cell from Icynene and Knauf, among others, with no proprietary lock-in.

Garage Ceiling Spray Foam
Garage ceiling foam in Redwood addresses the common scenario: attached garage with a bedroom above it, or detached shop you want to use year-round. We see a lot of converted garage spaces in Redwood’s older ranch properties, and the ceiling is usually an uninsulated floor assembly bleeding heat in both directions. Open-cell garage ceiling spray foam runs $1.80-$2.80 per board foot, with most Redwood jobs falling between $1,200 and $2,400 depending on square footage. We air-seal the garage-to-house wall and any penetrations before we foam, because insulation without sealing is just a filter.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Before
AfterTrusted Brands We Service in Redwood
We source spray foam materials from Icynene, Knauf, and Rockwool, among others - no proprietary product lock-in, which means we spec what your Redwood property actually needs rather than what our supplier is pushing this quarter. Our rigs carry multiple resin sets for different ambient conditions, because the humidity and temperature on a July morning in Gonzales County can differ significantly from what we’re seeing in Buda or Kyle that same day. We stock local-access replacement parts for our application equipment so a hose failure or gun issue doesn’t strand your job halfway through.
Common Spray Foam Insulation Problems We See in Redwood Homes

- Thin foam coverage on detached shop roof decks. Redwood’s 150°F+ July attics cook off-spec thickness and leave radiant heat pouring through. We meter thickness at every rafter bay with a depth gauge, and we photograph the readings for your Documented Photo Record.
- Rim joist foam applied over damp wood on old ranch houses. The ground moisture common in Redwood’s pier-and-beam crawl spaces traps under closed-cell foam and pops it. We moisture-check every rim and belly board with a pinless meter before we spray, and we document the readings.
- One-trip planning failures on acreage jobs. Running out of foam, missing a heated hose, or losing a return trip because the shop is 20 minutes off the county road. Our Redwood spray foam jobs use heavier-duty self-sufficient rigs and a full-tank start - we plan for the worst, not the best.
- Zero wall insulation discovered mid-job. After Winter Storm Uri, many Gonzales County homeowners learned their older homes had literally no insulation in exterior walls. We find this regularly in Redwood ranch houses built before the 1970s. When we encounter it, we stop, photograph, and present options with a revised written price before proceeding.
Pricing for Spray Foam Insulation in Redwood, TX
Most Redwood spray foam jobs fall in these ranges:
| Application | Price Range | Typical Board Feet |
|---|---|---|
| Open-cell attic/roof deck | $3,600-$9,100 | 2,000-3,500 |
| Closed-cell attic/roof deck | $7,000-$13,750 | 2,000-2,500 |
| Closed-cell rim joist (perimeter) | $800-$1,400 | 200-400 |
| Garage ceiling (open-cell) | $1,200-$2,400 | 600-1,200 |
| Detached shop, full envelope | $4,500-$11,000 | 1,500-3,000 |
What moves you within these ranges: roof pitch and accessibility, existing insulation removal, moisture remediation needed before spraying, and whether we’re treating house, shop, or both. Every job begins with a written price - flat, itemized, no work starts without it. Bring us a competing quote and we’ll read it with you; our Free Second Opinion applies to any written estimate. Call (737) 337-8049 for your written price.
We Also Serve Cities Near Redwood

Our crews work throughout the corridor between San Marcos, Kyle, Lockhart, and Buda, with Redwood and Gonzales County’s rural properties as a growing share of our route. If you’re on acreage outside these city limits, the same self-sufficient rig and one-trip planning applies. Our Spray Foam Insulation team coordinates dispatch from our Dallas-Fort Worth office to reach rural jobs efficiently.
Serving Redwood, TX - Our Local Coverage Area
We’re based in the Redwood 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 Redwood

It often makes more sense on the shop, because your house at least has some insulation while your metal shop has none and turns into a 154°F oven. We regularly foam detached shops in Redwood with closed-cell on the roof deck and rim joist, which drops interior temperatures by 60+ degrees and lets a window AC unit actually work. Call (737) 337-8049 for a written price on your shop - estimates are free.
Yes, and it’s exactly the fix for what Uri exposed. We drill and fill stud cavities with closed-cell foam from the exterior, seal the holes, and match your siding. Most Redwood ranch houses need 2-3 inches for R-13 to R-19 in the walls, at roughly $4-$6 per square foot of wall area. The key is air-sealing first, then insulating - we don’t blow foam over leaks. Call (737) 337-8049 for an exact quote - estimates are free.
Closed-cell on the rim joist and belly boards, but only after moisture-checking every surface. Redwood’s pier-and-beam crawl spaces breathe ground moisture year-round, and foam over wet wood fails within a season. We pinless-meter every board, document the readings, and if moisture is too high, we tell you what drying steps are needed first. Call (737) 337-8049 for a crawl space assessment - estimates are free.
Redwood attics routinely exceed 150°F in July and August, which is why we spec 5.5-7 inches of open-cell or 2-3 inches of closed-cell for a full R-38 assembly. The heat doesn’t just make your AC work harder; it degrades fiberglass batts and makes them settle faster. Spray foam adheres to the deck and doesn’t shift. Call (737) 337-8049 for a written price based on your attic measurements - estimates are free.
Yes, and we plan for it deliberately. Our rigs leave with full resin tanks, backup hoses, heated hose assemblies, and enough material for 20% over your estimated board footage. A return trip to a Redwood acreage property costs two hours of county-road driving, so we don’t risk it. You’ll get a named technician, a text when they’re on the way, and a Documented Photo Record when they leave. Call (737) 337-8049 to schedule - we answer live 24/7.
Written by Wes Okafor, Owner at Envelope Insulation Co., serving Redwood since 2016 under The Haven Standard.