Caulking and weatherstripping: sealing drafts around windows and doors
Updated · KeystoneProGuide editorial team
Is sealing drafts worth doing?
ENERGY STAR thinks so. It says that if you added up all the leaks, holes and gaps in a typical home's envelope, it would be like leaving a window open every day of the year, and that most U.S. homes are under-insulated and leaky. The EPA estimates that air sealing combined with added insulation in attics, floors over crawl spaces and basements saves homeowners an average of 15% on heating and cooling costs, or 11% of total energy costs. Sealing can also cut outside noise, keep out pollen, dust and insects, and help with humidity.
Windows and doors are the most accessible part of that work, though ENERGY STAR says they may save less energy than attic and basement projects.
How do you find the leaks?
ENERGY STAR lists the signs around window and door trim:
- a draft near a window or door that is closed;
- gaps you can see around the trim;
- dust or insects getting in around the frame;
- outside smells coming in;
- peeling paint around the frame.
It suggests two quick tests. Close a window on a sheet of paper: if the paper moves back and forth easily, the window could be tighter, and thicker weatherstripping can fix it. Or hold a lit incense stick near the seams and sash and watch whether the smoke is pushed one way, which points to a leak.
Which material fills which gap?
ENERGY STAR's guidance for sealing behind trim sorts the materials by gap size:
- Caulk for gaps of a quarter inch or less, with the crack cleaned out first and the bead smoothed to seal.
- Non-expanding foam made for windows and doors, for larger gaps; trim the excess once it hardens.
- Fiberglass or backer rod pressed into larger gaps between the jamb and the framing, without forcing it so hard that the frame bends, which can stop the window or door from opening and closing properly.
Weatherstripping is the answer where a window or door itself does not close tight, as the paper test shows.
Is this a DIY job or a handyman job?
Both, depending on how far you go. Running a bead of caulk or replacing weatherstripping is ordinary maintenance. Sealing behind the trim is more: ENERGY STAR rates it a moderate to difficult project that means prying off trim, removing old filler, sealing and nailing the trim back. It estimates one to two days and "$$" of materials for a homeowner, against about a day and "$$$" with a contractor, on its scale where "$" is under $100 and "$$$$$" is over $2,000. It recommends a professional for complicated trim with sills, quarter rounds or decorative accents.
If you handle fiberglass, ENERGY STAR advises a dust mask, gloves and eye protection.
What changes in an older house?
Two things: the paint and the windows. ENERGY STAR's own instructions say that if your home was built before 1978, or the work disturbs paint, you should first read the EPA's lead renovation resources, and that you may need a professional to deal with lead paint chips. For paid work, the EPA's rule applies once a job disturbs more than six square feet of paint per room inside or 20 square feet outside. Prying off and cutting old painted trim counts toward that.
Replacing glass in old windows is a lead question too: the EPA notes that old glazing putty is painted and must be removed to replace a pane.
Can you caulk over damp or moldy spots?
No. The EPA says not to paint or caulk moldy surfaces; clean the mold and dry the surface first, and fix the water problem that caused it. Condensation on windows is a sign of high humidity, which the EPA suggests keeping below 60 percent.
Is there anything you should not seal?
Vents. Sealing a house tighter is about closing unintended gaps, not the openings that fuel-burning appliances need. The Consumer Product Safety Commission warns that during home renovations, appliance vents and chimneys must not be blocked by tarps or debris, and it says a carbon monoxide alarm is added protection, not a substitute for the proper use and upkeep of fuel-burning appliances. If your furnace, water heater or dryer vents through a wall near the work, keep the vent opening clear.
What does it cost to hire?
The surveys price these as small jobs. HomeGuide lists caulking repair at $150 to $300 and weather stripping installation at $150 to $400,. Bundle every window and door in one visit to spread a minimum charge.
Is there help for low-income households?
Yes. ENERGY STAR points to the state Weatherization Assistance Program, which in Pennsylvania serves households at or below 200% of the federal poverty guidelines through local agencies in every county. In Chester County, the county lists weatherization through a Delaware County community action agency. The repair help guide has the local details, the lead paint guide explains the rule for older homes, and local businesses are on the handyman services page.
Sources
- Renovation, Repair and Painting Program: Contractors, U.S. Environmental Protection Agency
- Frequent Questions About Renovations Covered by the RRP Rule, U.S. Environmental Protection Agency
- A Brief Guide to Mold, Moisture and Your Home, U.S. Environmental Protection Agency
- Weatherization in PA, Pennsylvania Department of Community and Economic Development
- Housing Resources, Chester County
- Carbon Monoxide Fact Sheet, U.S. Consumer Product Safety Commission
- Why Seal and Insulate?, ENERGY STAR (U.S. Environmental Protection Agency)
- Sealing Behind Window & Door Trim Project, ENERGY STAR (U.S. Environmental Protection Agency)
- Handyman Hourly Rates, Price List and Average Job Cost, HomeGuide