Keepin the Heat in!

Sill plate and Rim Joist Insulating:

RIM JOIST INSULATION WITH FOAM BOARD AND SPRAY FOAM

Last winter, our children were cold. Picture this...a raised ranch. The basement level has our bedroom and the Wood Stove on the far left (the D side for the Firefighters in the group. ) The Kids rooms are at the opposite side of the house on the main floor. (A/B & B/C sides) Nana stays in the living room right above the wood stove. She is always hot and keeps the oil baseboard heaters set to 60f. So when it is cold, my room and the basement is 80f and the kids rooms on the opposite side and up one floor is always really cold. Last year we let them run a small ceramic heater and a big infrared heater in the other bedroom. My plan was to pipe a hot water jacket from the wood stove into the baseboard heater system. We then decided to hold off on that until we replace the oil boiler with an on-demand propane water boiler. I also had planned to insulate the rim joist.

We had bought a bunch of 2 inch foam board and spray foam for the greenhouse. Given that project remains foundering, we decided to use some of that material to insulate the rim joist. Years ago, I worked for a company called Dr. Energy Saver out of Seymour CT. This is a division of CT Basement Systems...All things basementy...what we did was make

homes more comfortable and energy efficient. The basic idea is that every hole in your house lets air out or in. The cable company drills a hole to run a wire into the house, air leaks around the wire. We had ways to seal off any room or situation. What is the sill plate and rim joist? This is where the wood meets the cement. The house foundation is poured. The sill plate is the board that rests on the cement and the rim joist is what the floor joists are attached to. Now, no matter how well the concrete was poured, it wont be perfectly level. There will be gaps between the sill plate and the concrete. The rim joist is then just outside of that, covered with insulation and siding, but leaking just the same. Air leaks through this part of the house, unless the house has been encapsulated in spray foam insulation.

Lets talk a moment about fiberglass insulation. Fiberglass is an excellent insulator when encapsulated...It has to be covered by wall on both sides. Many houses have fiberglass insulation stuffed into the floor joists and open to the basement. We had this, with the insulation stuffed into the cantilever of the first floor. It does not do anything for your house if you have soffit and a cantilevered first floor. So, in the pictures, you can see the foam board block cut to fit in between each set of floor joists. Then I sprayed foam around the edge to ensure an air tight seal. Prior to this, cold air from the outside would waft into the wall from the rim joist and travel up, being pulled into the living areas of the house by the hot air moving up and escaping from around the windows and ceiling lights. With the flow of air stopped, the warm air in the bedrooms cannot run away as quickly as there is no cold air "chasing" the warm. The next step is to remove the soffit, pull out all the useless fiberglass and fill the spaces with foam blocks and 'picture-framed' with spray foam. As they sit now, air will travel into the soffet and into the floor keeping the floors freezing cold and allowing more hot air to escape throughout the house. The other step in warming the kids bedrooms is to cut floor registers. I have ordered 4in x 10 in floor registers with fans built in. With the basement sealed off, heat from the wood stove will move to the far side of the basement and get sucked up into the bedrooms. I have faith this will warm their rooms and cool mine. Let me end with an anecdote: While I was doing the job, we kept the stove going as foam works better warm. We filled it at 9am and let it burn down throughout the day. At bedtime it was 74 in my room. It was 45 outside overnight and we were at 70 in the morning. In the past when we failed to start the stove on a 50 night, it would be 64 in my bedroom in the morning. That alone is worth the energy and misery to insulate. This is a simple project that anyone can do. The money saved from the energy saved will make it a worthwhile project, not to mention actually being warm and comfortable in your house.