Crawl Space Insulation - Same-Day Service, Done Right the First Time

Trusted Crawl Space Insulation Nationwide

Crawl space insulation is the most overlooked upgrade in a house with a raised foundation. Cold floors, damp air, a musty smell in the hallway and heating bills that never make sense all trace back to the same dark space under your feet. Woolsey Attic Insulation has focused on insulation only since 2002, working as part of the Kingswell family of independently owned and operated insulation companies. We insulate, seal, and restore crawl spaces for homeowners across the United States, with background-checked, uniformed technicians on every job and a live person answering the phone 24/7 at (325) 240-5411. Every job starts with a written price before any work begins, and every installation carries the Kingswell Guarantee in writing.

Call (325) 240-5411

Most people think of insulation as an attic job. The crawl space is just as important, because the floor above it is the largest surface in your house that touches unconditioned air. Glenn Hartley leads the Woolsey team with one standard: if the number changes at the door, the deal is off. We have been doing crawl space work that way since 2002, and we are happy to explain exactly what we find under your house and what it will take to fix it.

Key Takeaways

• Most crawl space insulation jobs run between $1,500 and $5,000 depending on square footage, the method, and how much moisture work is needed. You get the exact written number before any work starts.
• We insulate the right surface for your crawl space. Floor joists in a vented crawl space, foundation walls in a sealed one. Mixing those up is the most common mistake in this trade.
• The 365-Day Done Right Promise covers every job in writing: if it isn’t right within a year, we come back and fix it at no charge.
• A live person answers the phone 24/7. Not a voicemail maze, not a call-back window.

Why Crawl Space Insulation Matters

Crawl Space Insulation is the layer of material installed under your first floor or along the crawl space walls to slow heat loss, block moisture, and keep the floors above comfortable. Without it, cold air moves straight up through the subfloor in winter, and hot, humid air does the same in summer. The result is a house that is hard to heat and cool, floors that feel cold under bare feet, and ductwork or plumbing in the crawl space that works harder than it should. Woolsey Attic Insulation installs crawl space insulation in homes across the country, matched to your climate zone and the way your foundation was built. A typical crawl space insulation job runs $1,500 to $5,000, and you will see the written price before any work begins. If your attic is also thin, we can quote both at once, and you can read more about our attic insulation work.

What Poor Crawl Space Insulation Costs You

A bare or poorly insulated crawl space can account for a real share of your heating and cooling loss, and it drives up humidity in the whole house. Damp joists invite mold and wood rot, and wet insulation hanging off the floor stops doing its job at all. Fixing the crawl space is often the cheapest comfort upgrade a homeowner can make.

Vented or Sealed, Which One Do You Have

Older homes usually have a vented crawl space with small openings in the foundation wall. Newer building practice favors a sealed, conditioned crawl space with a vapor barrier on the ground and insulation on the walls. We inspect yours first and recommend the approach that fits the house, the climate, and the budget.

Crawl Space Insulation Methods

There is no single right way to insulate under a house. The best material depends on whether the space is vented, how often it floods or gets damp, how much headroom there is, and what lives down there, like ducts and pipes. Woolsey Attic Insulation works with spray foam, rigid foam board, fiberglass batts, and mineral wool, and we choose based on the conditions we measure, not on whatever is on the truck.

Floor Insulation Between Joists

For a vented crawl space, insulation goes in the floor joist bays directly under the subfloor. Fiberglass or mineral wool batts are held in place with support wires or netting, and they need to touch the subfloor with no gaps. Batts that sag or sit loose do almost nothing, so fit matters more than thickness.

Foundation Wall Insulation

For a sealed crawl space, we insulate the foundation walls instead of the floor. Rigid foam board or closed-cell spray foam goes on the wall surface, paired with a ground vapor barrier. This keeps the crawl space inside your thermal envelope and protects ducts and plumbing from freezing.

Spray Foam for Tight Spots

Closed-cell spray foam seals air leaks and adds a moisture barrier in one pass. It costs more per square foot than batts, but it works well on rim joists, uneven walls, and low crawl spaces where board stock is hard to fit.

Batts and Mineral Wool

Fiberglass and mineral wool batts are the lower cost option for vented crawl spaces with dry conditions. Mineral wool resists moisture and fire better, which is why we recommend it in humid climates.

Moisture, Vapor Barriers and Air Sealing

Insulation in a wet crawl space fails. Before we put a single batt or board down, we look for standing water, wet soil, plumbing leaks, and missing gutters or downspouts that dump water against the foundation. A heavy plastic vapor barrier laid across the ground and sealed up the walls stops the soil from pumping moisture into the air. Moisture control usually adds $500 to $2,000 to a job, depending on the size of the space and how much work the ground needs.

Sealing Air Leaks First

Rim joists, plumbing penetrations, and wiring holes let air flow straight into the house. We seal these gaps with foam or caulk before insulating, the same approach we use in attic air sealing. Insulation slows heat, but it does not stop air, so the sealing step is what makes the numbers work.

When Standing Water Is the Problem

If your crawl space floods, insulation is not the first fix. We will tell you plainly when drainage or a sump pump has to come first, and we will not sell you insulation that will be soaked by spring.

Removing Old or Damaged Crawl Space Insulation

Old fiberglass that has fallen from the joists, insulation soaked by a past leak, and material chewed up by rodents all need to come out before new insulation goes in. Installing over contaminated material just seals the problem in. Woolsey Attic Insulation handles insulation removal in crawl spaces with commercial vacuums, protective gear, and proper disposal. Removal typically adds $700 to $2,000 to a job, depending on how much material there is and how tight the space is.

Pests and Mold Under the House

Mice, rats, and raccoons love a warm crawl space with loose insulation. If we find droppings, nesting, or mold on the joists, we document it with photos, tell you what we see, and include cleanup in your written price before we start.

Crawl Space Insulation vs Attic Insulation

Homeowners often ask which one to do first. If your attic has less than the recommended R-value for your climate zone, start there, because heat rises and the attic is where most of it escapes. If your floors are cold and your attic is already in good shape, the crawl space is the better next step. Many homes need both, and the work pairs well on a single visit. We also install blown-in insulation in attics, which is often the fastest way to raise whole-house efficiency.

Our technician will measure both spaces, tell you where the biggest gains are, and put the whole plan in writing. You decide what to do, in what order, and on what budget.

Signs You Need a Pro Right Now

• Floors that feel cold in winter. If the floor is cold even when the thermostat is set high, heat is escaping through an uninsulated or poorly insulated crawl space.
• A musty smell in the house. Air from a damp crawl space rises into the living area. That smell usually means trapped moisture and possible mold.
• Insulation sagging or lying on the ground. Batts that have fallen from the joists are not doing anything, and they hold moisture against the soil.
• Frozen or sweating pipes. Plumbing under the house freezes when the crawl space is cold and open to outside air. Sweating pipes mean humidity is too high.
• Pest activity. Droppings, chewed material, or scratching under the floor all point to animals living in the crawl space.

Our Process, Step by Step

1. 1
   Call and talk to a live person. No voicemail maze, no call-back window. When you call (325) 240-5411, a real person answers 24/7 and gets your situation on our schedule.
2. 2
   On-site inspection and written quote. A background-checked technician goes into the crawl space, measures it, checks for moisture, pests, and air leaks, and gives you a written price before any work starts. That number does not change at the door.
3. 3
   Prep and cleanup of the space. We protect your home, clear out damaged material if needed, and fix drainage or moisture issues before insulating.
4. 4
   Installation done right. The crew installs the insulation and vapor barrier that fit your crawl space, seals the air leaks, and cleans up before leaving.
5. 5
   Written guarantee and follow-up. Every job gets a written guarantee, included, for 365 days. If anything is not done right within that year, we come back and make it right at no charge.

How Much Does Crawl Space Insulation Cost?

Where We Work

Woolsey Attic Insulation serves homeowners across the United States through local crews under the Kingswell banner. Each location is independently owned and operated, which means the crew that shows up at your door is part of your community, not a corporate dispatch from somewhere else. Wherever you are, the standard is the same: written price before work starts, a committed arrival window, a clean job site, and a written guarantee on every job. We will connect you to the Woolsey team nearest you when you call.

Frequently Asked Questions About Crawl Space Insulation

Schedule Your Crawl Space Insulation Service Today

If your floors are cold, your crawl space smells damp, or your insulation is sagging, the fix starts with one phone call. Call (325) 240-5411 and talk to a live person, any hour of the day or night. We will schedule a visit, take measurements, and hand you a written price before any work starts. No obligation, no door-step surprises, and every job covered by the Kingswell Guarantee in writing. That is the only way we have done it since 2002, and it is the only way we will. You can also start from our home page to see everything we do. Call today.

Written by Glenn Hartley, Owner at Woolsey Attic Insulation, serving homeowners across the United States since 2002.