Weatherproofing & Draft Sealing — Stop Paying to Heat and Cool the Outdoors
Every gap around a window frame, every failed door sweep, every unsealed penetration through an exterior wall is moving conditioned air out and unconditioned air in — every hour your HVAC runs. NorTech’s weatherproofing professionals find every leakage point, seal it with the right material for that location, and put a measurable dent in what you spend on heating and cooling every month.
Request a QuoteEvery repair is backed by NorTech’s 1-year labor warranty. If any issue returns within 12 months, we come back and fix it. View warranty details →
Limited-Time Offer
15% Off Your First Weatherproofing Service
Apply at booking. Valid on draft audits, weatherstripping, caulking, vent sealing, and full weatherproofing projects.
Warning: Air Leaks Cost You Money Every Hour Your HVAC Runs — These Are the Signs Your Home Has Them
Air infiltration is the most expensive home maintenance problem most homeowners never address because it’s invisible. You don’t see a draft the way you see a cracked window or a leaking roof. You see it on your utility bill — a number that’s higher than it should be, month after month, for years. The U.S. Department of Energy estimates that air leaks account for 25–40% of the energy used for heating and cooling in a typical home. These are the signs that your home’s envelope has failed and is costing you money right now.
Drafts Near Windows or Doors
A perceptible draft near a closed window or door when the HVAC is running means the weatherstripping or frame seal has failed completely. The gap doesn’t have to be visible to be moving significant air — even a 1/8-inch gap around a door perimeter has the equivalent air leakage area of a small hole through the wall.
Rooms That Won’t Stay Comfortable
Rooms that are consistently too hot in summer or too cold in winter despite functioning HVAC typically have localized air leakage — either through the ceiling plane into the attic, through exterior wall penetrations, or through windows and doors with failed weatherstripping.
Energy Bills Rising Without Explanation
If your utility bills have increased year over year without a change in usage patterns, the most likely cause is degrading weatherstripping and caulk that has been failing incrementally. Each failed seal adds a small amount to your HVAC load — the aggregate effect compounds across dozens of small failures throughout the home.
Dust on Outlets and Switches on Exterior Walls
Electrical boxes on exterior walls are common air infiltration points. Dust rings or streaking around outlet plates on exterior walls is visual evidence of air moving through the wall cavity at that location — the same wall cavity that connects to the attic and crawl space through open stud bays.
Interior Humidity Problems in Hot Climates
In Houston, Miami, Tampa, and Orlando, humid outdoor air entering through gaps and penetrations is the primary cause of interior humidity problems that persist despite running the AC. Humid air entering the building envelope condenses on cooler surfaces in wall and ceiling cavities — driving mold growth that is invisible from the interior.
Ice Dams or Frost on the Attic Deck in Winter
In cold climates, warm moist air from the living space that escapes through ceiling penetrations into the attic condenses and freezes on the cold attic deck. Ice on the underside of roof sheathing or ice dam formation at the eave are direct indicators of inadequate attic air sealing below.
Weatherproofing & Draft Sealing Services We Perform
Weatherproofing addresses both the moving components — doors, windows, garage doors — and the stationary building envelope — walls, penetrations, attic, and crawl space. NorTech professionals handle both sides of the building envelope.
Doors, Windows & Openings
The moving components of the building envelope — where weatherstripping and threshold seals do the work.
- Door weatherstripping replacement — all door types and frame profiles
- Door sweep and threshold seal replacement
- Window weatherstripping replacement — double-hung, casement, and sliding
- Window frame caulking — interior and exterior perimeter joints
- Garage door weatherstripping — top, bottom, and side seals
- Pet door and mail slot draft sealing
- Storm door adjustment and seal inspection
Building Envelope & Penetration Sealing
The stationary building shell — where caulk, foam, and air barrier materials stop infiltration through the structure itself.
- Full exterior perimeter caulking — siding joints, trim, and transitions
- Utility penetration sealing — pipes, wires, conduit, and cables
- Recessed light fixture air sealing in the attic
- Attic hatch and pull-down stair weatherstripping and insulation cover
- Top plate and rim joist air sealing
- Crawl space foundation vent sealing for conditioned crawl spaces
- Draft audit — full home assessment of air leakage points and priority ranking
Where Air Actually Leaks Out of Your Home
Most homeowners focus on windows and doors — but research consistently shows those are not the largest air leakage sources in a typical home. Here’s where the air is actually going, ranked by impact.
Ceiling & Attic Floor Penetrations
The largest single source of air leakage in most homes. Open stud bays, top plates, recessed lights, electrical boxes, and plumbing penetrations through the ceiling plane allow warm air to rise into the attic continuously. Sealing these is the highest-impact weatherproofing measure in most homes.
Walls — Electrical Outlets & Switches
Electrical boxes on exterior walls are typically open to the wall cavity — which connects to the attic above and the crawl space below. Foam gaskets behind outlet and switch plates on exterior walls are an inexpensive, high-return air sealing measure most homes don’t have.
Floors — Crawl Space & Rim Joist
The rim joist — the perimeter framing at the base of the home’s floor system — is a major thermal and air leakage boundary in homes with vented crawl spaces or basements. Gaps between the sill plate and foundation and open rim joist cavities move significant air and thermal load.
Fireplace & Chimney
An open or unsealed fireplace damper is essentially a hole through the ceiling. When not in use, a fireplace without a closed damper or an inflatable chimney balloon moves more air than most windows and doors combined — a fact that surprises most homeowners when it’s quantified.
Plumbing & HVAC Penetrations
Pipes, ducts, and conduit passing through exterior walls, floors, and ceilings often have gaps around them that were never sealed at installation. A single unsealed 3-inch pipe penetration through an exterior wall has more air leakage area than a poorly sealed window.
Doors & Windows
Doors and windows account for roughly 10–15% of total home air leakage in a typical home — significant, but not the dominant source most people assume. Failed weatherstripping and deteriorated caulk at the frame perimeter are the two primary failure modes to address.
Common Weatherproofing Problems We Find & Fix
These are the six most frequent weatherproofing failures NorTech professionals diagnose across homes in Houston, Dallas, Atlanta, Phoenix, Denver, Nashville, and throughout the country.
Flat or Compressed Door Weatherstripping
Foam and pile weatherstripping compresses permanently over time and stops creating an effective seal. A door that closes easily but shows light around the edges when inspected has weatherstripping that has lost its ability to compress and recover — it requires replacement, not adjustment.
Failed Exterior Caulk at Window Frames
Exterior caulk at the joint between window frames and siding deteriorates on a 5–10 year cycle. Cracked or separated caulk at window perimeters allows both air and water infiltration. In Houston, Miami, and Tampa, this is one of the primary drivers of interior humidity problems and mold risk.
Unsealed Attic Penetrations
Recessed light fixtures, top plates above interior walls, attic hatch frames, and plumbing vent penetrations through the ceiling are frequently left unsealed even in newer construction. The cumulative air leakage through these openings often exceeds the leakage through all windows and doors combined.
Garage Door Bottom Seal Failure
The rubber bottom seal on garage doors deteriorates faster than any other weatherstripping on the home — exposed to UV, vehicle traffic, and direct ground contact year-round. A failed garage door bottom seal allows unconditioned air, pests, and water directly into the garage and through any attached walls into the home.
Utility Penetrations Left Open
Cable, conduit, gas line, and plumbing penetrations through exterior walls are commonly installed with gaps around the pipe that were never sealed. These penetrations go unnoticed because they’re often behind cabinets, in closets, or in mechanical rooms — but they move air and moisture continuously regardless of their visibility.
Attic Hatch with No Insulation Cover
Pull-down attic stairs and hatches are typically uninsulated and poorly weatherstripped — creating a large, poorly sealed opening directly into the attic. An attic hatch without a properly fitted insulated cover is responsible for a disproportionate share of ceiling air leakage in homes where it exists.
Weatherproofing Priorities Vary by Climate
The right weatherproofing strategy depends on where you live. Hot-humid and cold climates have different air infiltration failure modes — and different consequences when the envelope fails.
Hot & Humid Climates — Houston, Miami, Tampa, Orlando, Jacksonville
The primary concern is humid outdoor air infiltrating the building envelope and condensing on cooler interior surfaces. Air sealing prevents moisture-laden air from entering the wall and ceiling cavities where it cannot dry out. Window caulking, door weatherstripping, and exterior penetration sealing are the highest-priority measures. Vapor drive is outward in winter and inward in summer — the air sealing strategy must account for both directions.
Cold & Mixed Climates — Denver, Nashville, Charlotte, Raleigh, Dallas
The primary concern is warm interior air escaping through the ceiling plane into the attic — carrying moisture that condenses and freezes on cold attic surfaces, and driving ice dam formation at the eave. Attic air sealing is the single highest-impact weatherproofing measure in cold climates. Door and window weatherstripping addresses comfort and secondary energy losses. Rim joist and crawl space sealing address floor-level thermal performance.
Hot & Dry Climates — Phoenix, Las Vegas, San Antonio, Austin
Extreme summer heat combined with high solar gain makes cooling load the dominant energy cost. Air infiltration brings hot exterior air in and allows cooled interior air to escape simultaneously — doubling the impact on the HVAC system. Duct sealing and penetration sealing have high returns in these markets. UV degradation of exterior caulk and weatherstripping is accelerated — replacement cycles are shorter than in moderate climates.
Mixed Climates — Atlanta, Charlotte, Dallas, Nashville
Homes in mixed climates need weatherproofing strategies that perform in both heating and cooling seasons. The building envelope sees hot humid summers and cold dry winters — placing different demands on air and moisture management at different times of year. A comprehensive draft audit identifies which measures have the highest impact given your specific home’s construction and the dominant seasonal energy cost in your market.
How Much Does Weatherproofing Cost?
Weatherproofing costs range from minor — replacing weatherstripping on a few doors — to comprehensive whole-home air sealing projects that address the attic, crawl space, and full building envelope. The return on investment is among the highest of any home improvement. Here’s what drives the cost on every job.
Scope of Work
Replacing weatherstripping on two exterior doors is a minor, fast job. A full draft audit followed by attic air sealing, rim joist sealing, full exterior caulking, and weatherstripping replacement across all openings is a comprehensive project priced accordingly — but with proportionally higher energy savings.
Number of Openings & Penetrations
Homes with more exterior doors, windows, and utility penetrations have more individual air sealing points. A larger home with more openings costs more to fully weatherproof than a smaller one — but also has proportionally more energy savings available from the work.
Attic & Crawl Space Access
Attic air sealing requires working in the attic space — which varies in accessibility, depth, and insulation coverage. Crawl space sealing varies by height clearance, moisture conditions, and existing insulation. Difficult access adds to labor time and cost.
Material Type
Standard foam weatherstripping is inexpensive. V-strip, magnetic, and compression seal products last longer and cost more. Two-part spray foam for penetration sealing, rigid foam board for attic hatch covers, and professional-grade exterior caulk for frame perimeters are specified by location and performance requirement.
NorTech’s pricing approach: Every weatherproofing project starts with a draft audit — a full walk of the home identifying all significant air leakage points and ranking them by impact. Your technician presents a written upfront estimate before any sealing work begins. Use code NORTECH15 to save 15% on your first service.
What Homeowners Say About NorTech Weatherproofing Services
“Energy bills had been climbing for three years. NorTech did a full audit — found the attic hatch had no insulation cover at all, four recessed lights with open gaps into the attic, and two doors with completely flat weatherstripping. Fixed everything in one visit. First utility bill after was noticeably lower.”
“Master bedroom was always cold in winter and I assumed it was a heating problem. NorTech found the issue in about ten minutes — the exterior wall had a cable penetration that was completely open, and the window weatherstripping had failed on both windows. Sealed both, room temperature is now consistent with the rest of the house.”
“Had all the exterior caulking redone before repainting — NorTech stripped the old material, cleaned all the joints, and applied new sealant around every window, door, and corner board on the house. Good prep work that most painters skip. Took a full day for a large two-story home.”
“Houston summers with humidity coming through the walls — turns out the original builder left half a dozen penetrations unsealed in the exterior walls. NorTech found and sealed all of them, replaced the weatherstripping on the back door, and recaulked all the windows. Interior humidity dropped measurably.”
“Garage door seals — top, bottom, and both sides — were all deteriorated. NorTech replaced everything in one visit. The garage is noticeably cooler in summer now and the door seals properly for the first time since we bought the house. Straightforward job, fairly priced.”
“Had the attic air sealing done as part of a larger energy efficiency project. NorTech sealed all the top plates, the attic hatch, and every recessed light in the ceiling. Combined with new insulation on top, the difference in how the house holds temperature is significant. Would have done it years earlier if I’d known.”
Frequently Asked Questions — Weatherproofing & Draft Sealing
Common questions about weatherproofing costs, energy savings, air sealing methods, and what to expect from NorTech.
How much does weatherproofing a house cost?
Weatherproofing costs depend on scope — replacing weatherstripping on a few doors costs significantly less than a comprehensive whole-home draft audit and sealing project. NorTech provides a written upfront estimate after an on-site assessment. Use code NORTECH15 for 15% off your first service.
How do I know if my home has air leaks?
Common signs include drafts near closed windows or doors, rooms that won’t stay comfortable, rising energy bills without a usage change, dust accumulation around outlets on exterior walls, and persistent interior humidity in hot-humid climates. A NorTech draft audit identifies all significant air leakage points and prioritizes them by impact.
What is the difference between weatherstripping and caulking?
Weatherstripping seals moving components — doors and operable windows. It must be compressible and durable enough for repeated contact. Caulking seals stationary joints — between trim and siding, around window frames, at penetrations. Both are required for a complete air seal. Using caulk where movement occurs causes it to crack; using weatherstripping where rigidity is needed causes it to gap.
How much can weatherproofing reduce my energy bill?
The U.S. Department of Energy estimates that air sealing and weatherization can reduce heating and cooling costs by 10–20% in a typical home. Homes with older weatherstripping and no attic air sealing typically see the largest reductions. The return on investment for weatherproofing is among the highest of any home improvement.
What is attic air sealing and why does it matter?
Attic air sealing addresses gaps and penetrations in the ceiling plane that allow conditioned air to escape into the attic. Common leakage points include top plates, recessed light fixtures, attic hatch frames, and plumbing penetrations. It is one of the highest-impact weatherproofing measures because warm air rises — the stack effect continuously pulls conditioned air up and out when the ceiling plane is unsealed.
Does weatherproofing help with moisture as well as drafts?
Yes. Air infiltration carries moisture with it. In humid climates like Houston, Miami, and Tampa, warm humid air entering the building envelope through gaps condenses on cooler surfaces inside the wall or ceiling cavity — one of the primary causes of interior mold and insulation degradation in hot-humid climates.
How long does weatherstripping last?
Door and window weatherstripping typically lasts 3–7 years depending on material, frequency of use, and climate exposure. Foam deteriorates fastest. V-strip and door sweep products last longer. Weatherstripping that has compressed flat, torn, or separated is no longer providing an air seal and should be replaced.
What areas of the home lose the most heat or cooling?
The attic floor and ceiling plane is typically the largest air leakage source — warm air rises and exits through gaps in the ceiling continuously. After that, electrical boxes on exterior walls, plumbing and HVAC penetrations, and rim joists account for significant infiltration. Doors and windows, while the most visible issue, typically account for a smaller share of total air leakage than most homeowners expect.
Weatherproofing & Draft Sealing Services Near You
Serving homeowners across the country — every climate has air leakage problems, and every climate has energy savings waiting to be captured. View full service territory →
Your HVAC Is Running — Make Sure It’s Not Working Against an Open Envelope
Get a free on-site draft audit and written upfront estimate from a certified weatherproofing professional in your area. Most jobs scheduled within 24–48 hours. First-time customers save 15% with code NORTECH15.
