DIY Home Insulation: 10 Gaps You Can Air Seal Yourself

September 11, 2014
niki dube

How to Save Energy at Home by Air Sealing 10 Leaky Spots

This post is part of our Max DYI Series, which to provides you with the tools, tips and tricks you need to tackle your own home insulation projects.

Places to Air Seal

Image source: New England Energy Consulting Company

In classic David Letterman style, below is reverse-order list of targeted projects for reducing those uncomfortable drafts in your home by closing gaps.

The general timeframe for this project depends on how truly ambitious you are. If you don’t include trips to Home Depot or Lowe’s, a long weekend might be sufficient time to get all of these done. Any work done in or around the electrical components, such as junction boxes should be done slowly and patiently for safety reasons. Turn all power off if removing switch plates or outlet covers.

Want more? Check out our other great tutorials in the Max DIY Series

Air leaks from gaps might seem trivial at first, but collectively it is equivalent to having many small holes in a boat. Eventually it would sink or you would fall over exhausted bailing the water out. In old DC homes, the flow of air from crawlspaces and cellars can also introduce unpleasant smells. The lack of air sealing and insulation allow these unpleasant moisture-induced currents to circulate in your home.

What’s You’ll Need

Tools and Materials
  • Door & Window Gap filler spray foam
  • Loose fiberglass insulation
  • Work gloves
  • Screw driver
  • Weather stripping

Got all that? Okay, let’s get started. Here are the top 10 places your home is leaking air.

Top 10 Air Leaks In Your House

10. Check all outlet boxes. Remove face plates. Most homes are poorly insulated around these boxes. If you do anything with these outlet boxes, TURN POWER OFF at the circuit breaker. I repeat, turn power off. These protective face plates are in place for a reason. Many old DC homes have either knob and tube wiring or poor sheathing insulating the wire that separates you from a biting 110 volts. Hardware stores sell insulation for the back of a face plate. It’s a stick on product. Also, spray foam can be applied very carefully to the exterior side of the junction box.

9. Windows. If you have double hung windows, make sure they latch tightly to create an air seal. Some latches can be replaced if worn or inoperative. Use weather stripping if a gap exists. Curtains and shades can make a big difference too. If you don’t have thermal or double paned windows, replace them. Apply for energy rebates. When reinstalled, make sure installer insulates around the jams and under the casings. Installers typically do not care about your home’s insulation properties.

8. Doors. Use weather seals; replace or adjust the threshold to tighten up to the bottom seal of the door. This includes dog doors. Hardware stores usually have many types of weather seals and strips from which to choose.

7. Unfinished basement, crawl spaces or cellar ceilings. List is too long to provide all the possibilities on what can be done in a basement or unfinished cellar. Cellars can be a major source of drafts and unpleasant odors. There are several different solutions for cellars.   It’s best to have a professional assess and recommend the best solution.

6. Attic openings including drop down stairs, stairwells, doors, and areas around pipe jacks, chimneys and soffits. This may require a visit to the roof. Roofs are notoriously unsafe for unsuspecting reasons. Pitch (angle of your roof), combined with age and condition of the shingles can make for a very slippery slope. There are ways to evaluate attic openings without going onto the roof but repairs are often made on the roof.

Be on the safe side, call or email Max Insulation for a free consultation and estimate – (202) 341-6015 |

5. Chimney. DC homes can have two types of chimneys. A chimney for carbon monoxide exhaust and one for fires. Chimneys are notorious for drafting a lot of conditioned air out into space. In either case, make sure you have a tight-fitting flu that opens and closes properly. Flashing around chimney should also be tight to prevent air and water leaks.

4. Hardwood floors. Many DC homes have hardwood floors attached right on top of the joists without insulation or moisture barriers underneath. The ground underneath can be a major source for cold, damp air. In my house, the former barbershop, the hardwood was in such bad shape from all the customers over the years, I just laid new hardwood right over the old with a moisture and insulation barrier in between. Results have been wonderful.

3. Ceiling lights. Ceiling lights are usually connected to a junction box in the ceiling that can provide an escape for warm or cold air into the attic. A properly insulated attic will address this. Go read: How To Insulate Your Attic.

2. Light switches. Similar to outlet boxes, uninsulated light switch boxes can provide a steady stream or outside hot or cold air. Turn of the power at the circuit breaker if you are going to be removing the switch plate.

1. Window air conditioners. Many DC homes lack central heat, ventilation and air conditioning systems or HVAC. Window AC units are always poorly fitted and allow drafts in both directions. Weather stripping is very effective with filling the window AC gaps.

Contact Max for a free consultation and estimate to live more comfortably in your home for less cost. Call or email us at or (202) 341-6015 (ask for Max).