# Insulate Ceiling Joists?



## HandyFrank (Jan 8, 2010)

I have an old home that was built before insulation was used. I have a room open and I can see right through the ceiling joists from the front of the house to the back based on the way the house ceiling slopes down in that area. I think it is technically Balloon Framing, but i'm not fully sure. Would it make sense for me to put some insulation in the end of the ceiling joist to stop cold air from penetrating both sides and the cavity between the 1st and 2nd floor in the ceiling joists?

I can easily stick an R-19 or R-30 in there to at least stop the cold air from being able to pass from the front to the back. The floor definitely feels cold on the 2nd floor in certain areas (Near the ends of the house) and exactly where I could stick insulation in some spots.

Or, was this type of construction done for a reason or for venting of some sort?

To reiterate, the second floor basically has a 2X8 standing upright, and there is no rim board and I can see right through from the front to back of the house through the ceiling joists. Maybe Balloon framing is what its called, I'm unsure.

Any tips appreciated.


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## joecaption (Nov 30, 2011)

Posting a picture would help clear it up.
If you do have balloon framing you need to be doing what's called fire blocking if the wall is open. 
Balloon framing act's like a chimney in a fire because the walls are open from the basement or crawl space all the way to the attic.
Fire blocking is just sealing up the tops and bottoms of the walls to stop the draft.
If the walls are 9' or taller add another block in the middle of the wall. 
While it's open would be a good time to up grade any wiring, or cables.


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## HandyFrank (Jan 8, 2010)

joecaption said:


> Posting a picture would help clear it up.
> If you do have balloon framing you need to be doing what's called fire blocking if the wall is open.
> Balloon framing act's like a chimney in a fire because the walls are open from the basement or crawl space all the way to the attic.
> Fire blocking is just sealing up the tops and bottoms of the walls to stop the draft.
> ...


Thanks for the tips. The house has some fire blocks already in the original construction as sill boards I think. So not a true balloon framing, but sort of.

The area I am talking about is from the front of the house to the back. The house has an overhang type front porch so there is void space in the ceiling of the front porch, which is between the upper part of the 1st floor, and the lower part of the 2nd floor. So the 2nd floor floor (Or 1st floor ceiling) joists are exposed and you can see from the front of the house to the back if you are looking through from the front porch ceiling which leads to the back porch overhang.

I'm hoping to close up the void today but if I have time to post a pic I will.


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## danpik (Sep 11, 2011)

If the ceiling joist bays do indeed open into the porch ceiling that should be addressed. Fiberglas insulation by itself is not an effective wind barrier. In fact, no air movement should occur in insulation. Air movement effectively pulls out the trapped warm air rendering the insulation useless. If there are openings, they should be blocked off with wood. Seal any cracks with spray foam or caulking and fill the area on the inside with fiberglass batting. This will stop air movement into the joist bays and keep the floors warmer. 

balloon framing usually refers to a method used in wall construction. Walls in two story homes were built using framing members that went from the foundation all the way up to the header on the second floor. There was a stud bay that went the height of both floors. fire blocking in the old days was not thought of or required. With these tall open stud bays and no insulation, fires could quickly move up inside a wall between floors and also get into the joist bays above the ceiling. Some balloon framed houses, including one I used to own, had the stud bays open from the basement all the way up to the attic. Great for fishing wires but really sucked when we had some of the walls blown in with insulation and we did not realize the openings were there


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