Insulating an old balloon frame
Here’s a cold climate (western Canada) insulation question for you all.
I’m about to start a reno on an old Sears and Roebuck kit house built about 1905. Brick outside of balloon framed 2×4, 2 storey. No insulation at all now; I’m planning to blow cellulose into the stud bays from the inside but wondering how to manage vapor barrier at the point of the 2nd floor joists. Inside each floor I’m going to use a barrier paint over the lath and plaster, seal trim and electrical box openings but I think I’m going to lose large amounts of air (and water and heat) through the joist bays into the walls.
I’ve seen these old balloon frames burn down in about 5 minutes and wonder if anyone’s ever retrofitted fireblocking and willing to share a secret or two.
My experience blowing insulation into older walls is all from eastern KY where I did a lot of those old coal camp houses, so I’m trying to translate a little bit for this climate.
thanks for all your thoughts. I’m not new to the magazine but I am new to the forum. i printed this question in the wrong folder a bit ago, so i hope yo’ll excuse me deleting and moving over here to the HVACies
Jeff
JT Renovation and Building
Cartwright, MB
Replies
There are arguments that denspak cells don't need VB as much because air migration is minimized.
I don't know how much of that would apply to the chimney effects for fire blocking. I add it at cieling level of the first floor when I have either cieling or walls or both openned up
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
What I thought was simple clapboard siding on an 1830s timberframe with balloon studding farmhouse , turns out to be 1 inch thick vertical tongue and groove with lath and plaster on the interior making it a tough old bird.
I find that I have a clear shot to each studbay from the attic as the bays dead end there and are open, thus eliminating the need to drill holes and plug except for corner bracing and the window studs, so dense pak is getting more and more attractive.
But I understand that the typical blower one might rent from a bigbox doesn't have the oomph needed to get the desired density.
When you do a building do you own your own blower, know a rental place that has what is needed, or somehow have a way to bolster the lightweight blowers to achieve the necessary pressure?
be a greenhorn
as Buddha said to the hotdog vendor .... "make me one with everything"
I use subs. You'll have to get Mike Smith's attention for that answer. He blows his own. As I remember, he teaches that you can't denspak a tall wall all the way from the top. Think about it - the hose goes down a couple feet ands then the loose fibre has to float all the way to the bottom. That would not be dens packing it, so it would settle later.My guy will remove siding or drill holes to bung afterwards when he has to maintain the interior, but I am usually tearing things up so he can staple up the retaining mesh and spary from inside, poking holes wherever he needs them. I also find that these old places have solid diagional bracing in some strange places so you will always have some few voids when you can't see where you are blowing.I know Mike needs to coment on this. He probably had more tricks up his sleeve.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
if you've got open topped stud bays your a lucky guy. It can be a wee bit finiky, but get an extra length of hose, a helper, and feed that sucker all the way down to the bottom of the bay. Then turn on the wind and slowly back it out and you've got nice compaction btm to top. If you pay attention it will also tell you which bays have bracing or blocking in them so you have to go inside/outside and pop a hole. This is not a good idea with top-plated bays since whatever little hole you drill won't be big enough for the feedin/slideout process. this place I'm working on (started it this afternoon) has great wide base trim throughout so I'll likely take it off on the 2nd floor, cut some holes, blow in from there, and install conventional fireblocking. thanks for your thoughts on this. Jeff
Consider drilling a hole in each stud bay and spraying in Great Stuff Pro (colored orange) as a fire block. Not as good as real fire stops but it may work well for a retrofit. Get yourself a good foam spray gun.
http://www.dow.com/buildingproducts/sprayfoam/news/20031201.htm
http://greatstuff.dow.com/pro/index.htm
Billy
Edited 9/7/2005 6:10 pm ET by Billy