Insulation – In rim joist cavities

In old houses that have not been insulated and/or remodeled the rim joists are covered with black mold and some dry rot.

This condition was and is being caused by no insulation on this area. With no insulation in this rim joist and the warmest air in any area is located at the ceiling. This air also has the most humidity in it.

When the air migrates across the ceiling to the out side wall 2 thing happen.

  • 1 humidity in the air is condensed on any cold surface, and being the rim with no insulation is the coldest surface, it condenses on it making it damp to actually wet to the touch. Creating a good area cool and damp for bugs, mold, and rot this an incredible ecosystem to be studied in a lab, not in your houses rim joist.
  • The 2nd thing that happens is it starts a thermo train where warm air rushes to the exterior wall, it cools and drops to the floor, then the air migrates across the floor to the center of the house where it’s warmed back up.

    Warm air being lighter than cold air it moved back up to the ceiling and the process starts all over.

    Adding insulation to the rim joist slows down the thermo train. If you install the wrong type of insulation you will cause a lot more mold and rot and invite many different type of bugs to live with you.

    The worst type of insulation is porous type (fiberglass, cellulose, mineral wool etc.) If this type is to be used install a vapor barrier on the warm side of the insulation to keep any humidity from getting into the insulation.

    Vapor barrier can be 6-mill poly — insulate, caulk all surfaces with a polybutylene caulk this stays soft than apply the poly over it and staple the poly in place making a perfect seal. Do this to all rim joist areas.

    Vapor barrier can be foam board — insulate, cut the foam board to fit snug in each rim joist space then caulk all edges of the foam board.

    Another way of getting around the problem is to insulate the rim from the outside. This only works in new construction while building.

    Move the rim joists in 2″ and install a 2″ foam board and then sheath over it. The drawback is you must install solid material where you are going to add a deck or other structural framing.

    Another type of insulation that can be used is Icynene this you can by on E-bay or hire a contractor to have is sprayed into the rim joist cavities.

    This type of insulation will not allow the humidity to pass through it making it great for this type of application.

    Insulation – In stud cavities Part 2

    Having blown in fiberglass or cellulose insulation into stud cavities works great for the first couple of years. But as the heating and cooling cycles go by moisture is allowed to migrate into the stud cavities with cellulose it make hard clumps losing R-value. When the house is shaken with the wind (jets) or ground vibrations (heavy trucks or railroad cars passing by) this vibrates the insulation down leaving hollow pockets of air or no R-value of insulation.

    This will happen at the top of all the walls and under all the windows as well as where wiring is run through the wall, the wiring holds up the insulation from settling
    downward but below the wiring there again is no insulation.

    Using an Open Cell insulation this sprays in place and bonds to the studs wires and wall sheathing locking it in place.
    The only draw back with Open Cell insulation is trying to fish wire into new outlets it’s hard to do.

    While fiberglass is easy just move it to the side pull the wire into place and install your electrical box, O by the way installing wire this way losses all you r-value in that stud cavity by moving the insulation you have created a void on the one side and on the other side you have pushed in to much insulation and have less R-value.

    What is R-Value and what R-Value do I need?

    Insulation is rated in terms of thermal resistance, called R-value, which indicates the resistance to heat flow. The higher the R-value, the greater the insulating effectiveness. The R-value of thermal insulation depends on the type of material, its thickness, and density.

    In the case of Icynene these are the facts:
    Thermal Resistance R 3.6/in x thickness of stud
    2×4=12.6 2×6=19.80
    Heat flow reduction through 1.0″ = 72.7%
    Heat flow reduction through 3.5″ = 92.2%
    Heat flow reduction through 5.5″ = 95.0%
    Heat flow reduction through 10.0″ = 97.3%

    What does this mean?
    Example-Look at your living room wall let’s remove a 14″ x 14″ piece of sheetrock & poly on the insides and on the out side let do the same size and location, remove the siding and wall sheathing so on both sides of the wall we can see the insulation.

    Now lets say it’s —2° below 0 and on the inside it’s 7° degrees.

    Standing out side dip your hands into water and place them on the siding just above the hole how long will be able to stand there before your hands freeze?

    Lets do the same with a house made of Icynene Insulation. Again how long before your hands freeze?

    A Fiberglass insulation — Never and instead your hands should be dry in under 6 minutes at —2° below °. Above the hole the temp should be on a calm day about 5°

    A Icynene Insulation- in about 30-40 Seconds major frost burn should start.

    The deference is that fiberglass insulation slows the air movement down inside the stud space while Icynene creates millions of little air pockets but not allowing them to move.

    Fiberglass insulation with out poly and/or wallboard on the in side and wall sheathing on the outside is really a very poor type of insulation in and of it’s self.

    Why is there frost inside my house

    I had a client upset because when she removed a blanket that was lying against the door. The blanket was frozen to the door and when she pulled it away from the door it removed the paint on the door. What actually happened? The door is a solid core wood door with an R-value of 2.47. This means in the winter with the outside temp of -20°F and 65°F inside. The center of the door is 17.5°F and it’s hard to maintain the temp. of 65°F at the surface of the door even with air moving across it. 5/8″ from the inside surface of the door is the freeze point of the door.

    Now lets put a blanket against the door. Next there is no air moving across the door and the blanket is like adding a blanket of insulation on the inside surface of the door.

    The new freeze point is now located at 1 1/2″ into the blanket so when the blanket is now removed the moisture in the blanket has frozen to the door. With this under standing let’s look at your windows.

    A window with Low E II will have an R-value of 3.5 – 3.75 Now let’s add drapes on the windows and people blame the window that it is bad.

    When in fact there are 2 problems 1 no air movement across the surface of the window and the humidity in the house is to high for the exterior temp.

    Tried of wet floors by the entry doors

    Are your entry floors wet and slippery from kids and adults tracking ice and snow in from the out side. If your basement under the entry floor is open you can install electric heat in the floor joist area.

    Install an electric heat thermostat on the entry wall then install the electric heater in the floor joist under the entry and wire it into the electrical panel.

    (Use a 220-volt heater) Set the thermostat about 5 degrees above the room temperature this will dry the floor out and dry the boots and shoes.

    If you set the temp higher you only waist electricity.

    Foundations – Draintile Post 1

    The code requires that you put draintile around the entire perimeter of the house at the bottom of the footing and then daylight it and /or run it to a sump tank. Installing the drain tile on the inside of the footing is known as cosmetic.

    The code also requires that 1/2 of the depth of the excavation around the building is back filled with course fill rock, sand and/or gravel. Continue reading

    Attic insulation part 2

    People say Cellulose is great let’s look Cellulose. Cellulose is made from ground-up newspapers and treated with flame retardant chemical. They say it won’t burn but when it does it burns (all thing burn if the temperature gets hot enough) in forms of well like mice trails so if you have a fire over the bedroom of the house. Continue reading

    Heating- Location of Equipment

    The more readily accessible the equipment, the easier it is to install, maintain, and ultimately replace.
    Working on equipment outside is great because you do not have to get into the home, unless you have no power or if the thermostat needs attention. More…

    Putting equipment above ground level often results in wasps and fowls finding a place to make their nests.

    Putting equipment on roofs becomes a pill for the maintenance person and the equipment now has an opportunity to leaking into the home.

    Putting the equipment at ground level opens up the opportunity for small animals to chew the wires and make their home in it.

    Installing the equipment in the home or a mechanical room keeps the wildlife out of the equipment and makes the environment safe for the technician to maintain it.

    Heating- Types of Fuels

    • Electricity

    Electricity has been the most costly in the past 30 years, but with energy costs jump on oil it may be the way to heat and cool the home.
    • Gas

    Next to electricity gas would be the easiest product to maintain.
    Simple concepts and the largest number of contractors work with this type of equipment.
    Gas has long been the leader in affordable heat.
    • Oil

    Oil is a good option, the concepts are simple but there are very few contractors who really understand how to fix the equipment when it needs maintenance.
    • Solar

    Some solar systems are very easy with little to no maintenance.
    However, the investment and size of the equipment is often large for the small return of investment.
    • Wood

    Wood, appears to be cheep, but requires vehicles, chain saws, a huge source of wood and teenagers.
    • Hybrids

    Dual fuel, Water source heat pumps, and much more are good options.
    The concepts are simple but there are very few contractors who really understand how to fix the equipment when it needs maintenance.

    Heating- Types of Cooling

    • Forced /Direct Cooling

    With direct conditioning of the air, you will get the quickest response from the equipment onto the air that is possible.
    I.E. Coming home to a cold house the air will cool down the faster because you are directly cooling the air.
    You can moisten, clean and condition the air. More…
    • Radiant Cooling

    With radiant conditioning of the air, it will take forever to get the home cool in a desirable amount of time.
    To my knowledge – no one makes this type of equipment.
    The concept is the same as the earth losing heat at night into space.
    I know of a couple of people who ran cold water in their radiant panels, only to find out that the humidity condensed on the panels and piping and ruined the non-stone construction of their homes.
    • Convection Heat

    See Radiant Cooling above.