Insulate a Basement Ceiling in an Old House :: How to Estimate & Install for Where You Live
As I stood in my basement, looking up at the floor joists of the dining room, I thought to myself, “I guess I do know a few things about insulation.”
I mean — I know that snowy days are perfect for jobs like insulating a basement ceiling with Owens Corning EcoTouch Insulation, of course.
Ha! And OK . . . . What I really mean is . . .
I know that insulation is meant to stop air movement. You insulate the areas through which air can potentially move.
I know that this here article on Building Science from friend Allison Bailes offers an easy to follow overview on the basics of air movement.
I know that insulation (and/or insulation effectiveness) is measured by R-Value, the “R” standing for Resistance as in “thermal resistance.”
I know (generally) that the thicker the insulation, the greater the insulation value (for a given set of materials and if installed correctly).
I know that when you are insulating with kraft paper “faced” insulation, the paper (a vapor barrier) always goes towards the conditioned (heated or cooled) space (and at least in my part of the country). And when cutting or installing, it is always best not to tear or puncture this paper.
I know that the most common insulating material these days is fiberglas. Batts, Rolls or Blown.
I know that fiberglas insulation should not be compressed when it is installed.
I know that installing insulation correctly (yes, there is an incorrect) is a fairly easy task.
And this is the “look” that we should be going for (roughly):
image via basiccarpentrytechniques.com
I do not know why we (OK, I) usually don’t think about insulating our home(s) till the winter. It’s not like insulation doesn’t help, say — keep the warm out (hence the cool in) during other months of the year. But it. just. is. So . . .
Why Insulate Now?
Well . . . personally . . .
Because it was on my todo list, though in not so many words – Insulate. Insulate at least portions of my basement as well as add to the insulation in the “crawlspace” area up under our back rooms (built out in a porch conversion).
And anyways, and in the winter months, there is almost always a slight (but very noticeable) temperature difference between our kitchen and our dining room. (You must pass thru the landing of a stairwell to go from one room to the other. ) And it is one spot, I think, where the original house was added onto, an addition — where things were not built quite so tightly.
A cool blast of air right there. And with the help of Owens Corning . . . it was time to get it fixed.
How to Insulate . . . ? (Short Version)
* Before I started I had to first figure out two very import things:
- What product should I use? I mean – I already knew I would be using Owens Corning’s EcoTouch, but what (or which) R-value? And Faced or Unfaced?
- How much of it would I need?
* Taking that, I started by measuring the space underneath my dining room. I measured the ceiling’s length and width (adding a little to accommodate both for “old house foundation walls” and “the band” < see my intro post at the link back there).
* I then measured the joist spacing, width and height, as well as the joist member thickness.
What I found here, as with most “old houses” (and built using a framing technique called balloon framing), the joist spacing was quite irregular, varying between a 16” oc in some places to, get this, a 20” oc spacing in others.
Beyond that I found that the interior spacing (inside of joist to inside of next joist) varied too. On a joist space of 16” on center, I pulled measurements from just a little over 13” to sometimes nearly 16”. (Uhhhh . . . old house! And SURELY this would make for a little added time. Oh well!) I would need insulation for both 16-inch and 24-inch framing, and . . . I would have to do some cutting.
Joist depth was, phew, easy enough at 10” and the joist thickness was actually 2” exact, making for a true 2×10 throughout.
* To determine which insulation thickness (read: R-value) I needed, I actually turned to the DOE’s “Insulation Facts.” (Maybe you’ll enjoy these easy to read graphics, and hey, there is also some fantastic info on insulation usage back there.)
I chose R-30 . . . batts.
* To determine how much I needed I turned to this handy insulation calculator offered by the Home Depot and Owens Corning. (I checked myself too with some simple math.)
* I took a quick trip to my local HD.
* Back at home, I cleaned my joist bays of all visible obstructions. I cleared out as much space as possible (in the room) to make working easier.
(And really there it is, in those few steps above, the hardest parts of this job. Oh! and then, there is the installation too.)
* While cross cutting of insulation is easy enough, rip cuts are, well, something I knew I wanted to take a little extra time with.
* Using a scrap piece of ¾’ plywood as a cutting station, a (drywallers) t-square, and both scissors and knifes (one utility & one folding) … I got jiggy. Here is a little bit of my work(ing) below:
* And that’s basically how it went. Measure, Cut, Hang, Repeat.
Taking special measures at the ceiling’s cross braces, I suspended the snugly fitted R-30 (kraft paper face up, of course) using Simpson Strong Tie’s Insulation Supports. Note: In most cases, these flexible metal “pins” needed to be cut down. (They are made, I know, for both 16″ oc & 24″ oc.) I did all cutting here using a pair of end cutters and a little bit of ummph.
While I am not quite finished with the entire room (about 70%), I wanted to get it up before the end of “insulation” season. (Hope you don’t blame me and I hope it helps.)
Something of a Review
I know that fiberglas insulation has historically be known to irritate the skin, eyes and throat. And I guarantee that I have had more than my fair share of “itchies” after a day of insulation. But, here, I have to give a nod to what the original DIY Guy (and his work) suggested. The Pink, while much like other insulations I’ve used, had the surprising characteristic of being, well, a little . . . gentler
for baby’s touch for these manly, and sometimes chainsaw-wielding, hands.
For the few hours that I have worked this project thus far, yep — sans gloves, sans sleeves (in some cases), no dust mask (though I probably would recommend it for dirty, dusty basements or attics), and, yes, sometimes sans eye protection … I only felt minor eye irritation one evening.
Call me guinea pig, and maybe I am building a tolerance. dk. And I can’t say I wasn’t advised; (shout to OC) here for recommended material handling.
Final Tip and Full Disclosure
I know you know you need insulation . . . and it’s good if you’ve got it, but not enough, or worse, not understanding the why and the how can seriously diminish its usefulness (just sayin’).
Thanks out to Owens Corning for including me in this fantastic program, and if I have to say it, I probably should say: In accordance with FTC guidelines, Owens Corning provided the materials for this project, but these are my opinions only, herein.
>> Thanks for reading and enjoy your weekend. ~jb
But Wait! Even More Moxie
A sweet homeowner tool >> Owens Corning’s Home Insulation Comfort Quiz.
. . . now I’m out, back maybe with update on my drafty dining room or maybe *fingers crossed* home energy savings.
Update :: Here is a fantastic article on developing a “Basement Insulation System” (esp. important with finished basements) via Todd Fratzel. (It made me re-think how I addressed the rim joists or “band” for this article.)
3 thoughts on “Insulate a Basement Ceiling in an Old House :: How to Estimate & Install for Where You Live”
Shortly after posting this I got pinged by friend and builder Todd Vendituoli. The Building Blox.
He asked if this was my house (… it is in fact) and he wrote this:
“Here’s what I’ve seen- in spring/summer the temperature differential between in and out will create moisture without a dehumidifier or adequate ventilation. That moisture will rise into the insulation and it will get soaked, possible fall down due to the weight of the water or create mold issues on the framing. I have seen all of these things happen and the corrections are not fun or cheap. Possible solutions: Cover the entire insulation area with plastic so the moisture hits but can’t soak in plus the ventilation and it should be good.”
It was a friendly ping and I am glad he voiced his concerns. 100% legitimate. Todd has been known (and I hope this is fair Todd) to work in more northern New England and/or the more southern Bahamas.
With that I replied – “I hope I did a good enough job on pointing out regional differences when insulating. (I am in the Mid-Atlantic, non-coastal, Baltimore and of course this project may be specific to my region.)
I had the exact same set up in my most previous house (less than a quarter mile away) without issue. I do not expect issue here but will monitor. “ (And have noticed an immediate improvement to the draftiness I was targeting.)
Other factors that come into play here: I have a cement basement floor, a stone foundation that does sometimes take water in heavy rains, (I currently do not have downspouts on my house – which I think is a direct cause there), there are 4 windows in the space, it is unconditioned (i.e. not heated or cooled), and despite taking water, signs of excessive moisture has never been present. But I did always and do plan to eventually add a dehumidifier to the area being insulated, but again I will likely watch this now with a little more of an intent eye.
Thanks Todd and thanks all. Always open for discussion. ~jb