Quick Answer
The easiest way to cut cold drafts in an older home without major renovations is targeted air-sealing: add weatherstripping to doors and windows, install door sweeps, caulk stationary gaps and trim, seal outlets/switches on exterior walls, and use window shrink film on leaky windows. These low-cost upgrades can be done in a weekend and often make a dramatic difference in comfort and heating costs.
Why Drafts Happen (and Where to Look)
Older homes leak air through many small gaps. The stack effect pulls warm air out at the top of the house and sucks cold air in at the bottom. Common leak points:
- Around doors (jambs, threshold) and window sashes
- Trim gaps at baseboards and window/door casings
- Electrical outlets/switches on exterior walls
- Attic hatch or pull-down stairs
- Fireplace dampers and around flues
- Basement rim joists and utility penetrations (pipes, cables)
A quick way to find leaks: on a breezy day, walk the house with an incense stick or smoke pencil and watch for smoke movement. An infrared thermometer also highlights cold spots.
Materials and Tools
- Weatherstripping: adhesive foam, V-seal, or silicone bulb (doors/windows)
- Door sweep or automatic door bottom (for exterior doors)
- Caulk: paintable acrylic-latex with silicone; high-quality exterior-grade for outside
- Low-expansion spray foam labeled “Window & Door” (small gaps around frames/penetrations)
- Outlet/switch foam gaskets; child-safe draft blockers for covers
- Window shrink film kits or removable rope caulk
- Chimney balloon or tight-fitting damper (if fireplace is unused)
- Cleaning supplies: mild detergent, rags, isopropyl alcohol
- Hand tools: utility knife, caulk gun, tape measure, putty knife, scissors, drill/driver (if installing thresholds)
- PPE: safety glasses, gloves, dust mask
Weatherstripping:
- Type: Adhesive foam, V-seal, or silicone bulb
- Size: 1/4–3/8 in compression
Door sweep:
- Gap target: no visible light; minimal drag on threshold
Caulk:
- Bead: ~1/8 in; paintable acrylic-latex + silicone
Foam:
- “Window & Door” low-expansion polyurethane
Attic hatch cover:
- Target R-value: R-10 to R-20
Step-by-Step: High-Impact, Low-Cost Fixes
1) Seal Exterior Doors (1–2 hours per door, $15–$40)
- Clean the jambs and let dry.
- Apply V-seal or silicone bulb weatherstrip on the stop so it lightly compresses when the door closes. Avoid over-compression.
- Install a door sweep on the bottom rail. Test with a flashlight: no light should be visible along the threshold.
- Check and adjust strike plate if the latch resists closing after sealing.
2) Weatherstrip Windows (30–60 minutes per window, $5–$15)
- For double-hungs: apply V-seal along the meeting rails and side tracks; use rope caulk along the sash-to-frame gap if windows are kept closed in winter.
- For very drafty windows you don’t plan to open: apply interior shrink film kits. Warm with a hair dryer to tighten.
3) Caulk Trim and Small Gaps (1–2 hours per room, $5–$10 per tube)
- Run a thin bead around interior casing where wood meets drywall and along baseboards on exterior walls.
- Fill gaps around pipe penetrations under sinks, behind toilets, and at cable/utility entries.
- Smooth with a wet finger or profiling tool for a neat joint.
4) Seal Outlets and Switches on Exterior Walls (5 minutes each, <$1 each)
- Turn off power at the breaker.
- Remove cover plates and insert foam gaskets. Reinstall plates and add child-safe draft blockers if needed.
5) Attic Hatch and Pull-Down Stairs (1–2 hours, $20–$60)
- Add adhesive weatherstrip around the hatch frame.
- Build or buy an insulated cover box for the hatch or stair opening to reach roughly R-10 to R-20.
6) Fireplace Drafts (30 minutes, $20–$60)
- If the fireplace is unused, close the damper tightly and install a chimney balloon or inflatable plug. Tag it so it’s removed before any future fire.
7) Basement and Rim Joist Touch-Ups (1–2 hours, $10–$20)
- Use low-expansion foam for gaps around sill plate, plumbing, and cable penetrations. For wide cracks, backer rod + caulk works well.
Safety and Best Practices
- Lead paint caution: in homes built before 1978, avoid sanding/abrading painted surfaces. If paint is damaged, follow EPA RRP guidelines.
- Electrical safety: always shut off power before working on outlets or switches.
- Ventilation and combustion: don’t block combustion air intakes for furnaces/boilers. Keep CO alarms working on each level.
- Foam use: choose low-expansion “Window & Door” foam near frames to avoid bowing. Wear gloves and eye protection.
- Ladder/step stool safety: place on stable surfaces and don’t overreach.
Common Mistakes to Avoid
- Over-compressing weatherstrip so doors won’t latch or windows bind.
- Sealing window weep holes (exterior drainage slots). Leave them open.
- Using high-expansion foam around windows/doors.
- Skipping surface prep: dirty or wet surfaces cause weatherstrip and caulk to fail.
- Forgetting the attic hatch; it’s often a major leak.
Costs, Time, and Priority Order
- Start with doors, attic hatch, and the draftiest windows for fastest comfort gains.
- A typical small home can see big improvement for $100–$300 in materials over a weekend.
- Expect a noticeable reduction in cold spots and fewer furnace cycles.
When to Call a Pro
- If rooms are still drafty after DIY sealing, a home energy audit with a blower door and infrared scan pinpoints hidden leaks.
- For major insulation upgrades (attic/roof, dense-pack walls) or spray foam at rim joists, hire a qualified contractor.
- If you have knob-and-tube wiring, consult an electrician before insulating.
- Masonry or window restoration work is best handled by specialists if frames are rotted or sashes are warped.
With a few focused hours and modest materials, you can drastically cut drafts without touching walls or replacing windows. Tackle the quick wins above, then consider an audit for deeper improvements if needed.