Best way(s) to bring house insulation up to comfortable levels.
February 16, 2016 3:11 PM   Subscribe

Original 1950’s construction 6 room (3 bedroom) cape cod style house north of Boston MA with varying levels of (inadequate) insulation. How do insulate this house?

My main concern is regarding the 2 bedrooms upstairs. Since there is no insulation at all in some parts of the house, we’re getting killed with the heating and cooling costs not to mention ice dams in winter and 95+ degree temps in the summer. I’m starting to see the plaster/drywall cracking because of the temperature differential.

The first level walls will get wrapped and insulated from the exterior this coming spring/summer when the cedar siding and windows are replaced with vinyl. Will that be enough to insulate and prevent drafts? Or do I need to empty several dozen cans of spray foam insulation/sealant along the foundation sill plate to remedy that?

The second level in the rear has new faced fiberglass insulation in the knee walls (by me), on the floor behind the knee walls (by me) and some in the roof (original).

The front has some original insulation in the knee wall in one room but nothing on the floor or ceiling/roof for either room. Just for reference, the original insulation looks like it was placed above the ceiling and draped over the side of the walls with most of it hanging away from the drywall in between the studs.

No insulation as far as I can tell in the very top portion of the gable anywhere.

I have access through the closet to get behind the knee walls both in the rear and front. I can (and plan to) insulate the walls and floor on the front portion of the house with faced fiberglass. Should I be using rigid foam in the wall/floor instead of fiberglass?

One of my questions is how do I get the ceiling/roof insulated without taking down the drywall or otherwise demolishing anything?

What should I be using? Rigid foam? What kind?

Would all this just be a stopgap solution for the ceiling/roof because it won’t be sealed?

I would like to keep the option of gutting the rooms as a very very last resort. Although we’re planning on doing a small addition at the rear entryway in the spring so maybe it would be a good time do it since we’ll have a dumpster already?

Or is the answer to just bite the bullet and hire a roofer (after the winter) to remove shingles, sheathing and add insulation from above before re-roofing?

I am also a bit discouraged by the results we got when we re-did the small sunroom last spring. Although we insulated it to higher than building code requirements (R49 in the ceiling, R13 walls, R38 in the floor), we’re getting a wicked air leak from around the baseboards and the bottom of the window frames, really evident now that the polar vortex was in effect this past week. Yes, the room is wrapped on the outside and has vinyl siding.

What the heck am I supposed to use to seal things up so the upstairs doesn’t have the same issue?
I’m happy to clarify anything or put up a diagram or drawing somewhere if needed.

As usual, thank you in advance.
posted by eatcake to Home & Garden (8 answers total) 7 users marked this as a favorite
Sign up to get a home energy assessment and then find out what rebates and credits are available to you to complete the work.

For my own part I found that attic insulation and blown in wall insulation had the biggest bang for their buck. Replacing windows is expensive and it takes a loooong time to recoup the costs of replacement. You could consider pop-in storm windows as an alternative.
posted by brookeb at 3:16 PM on February 16, 2016 [5 favorites]

Just want to add before too many people suggest this that I've already looked into the MassSave efficiency incentive program and none of it is available in my town. We have municipal electricity and oil forced hot air heat only. The utility company has appliance rebates but that's pretty much it.

The windows (with storm windows) are getting replaced regardless because they need to be. There is all sorts of wood rot in the frames and they are single pane double-hung weighted windows (probably with lead in them). Besides storm windows are not really air tight, just mostly to keep water and debris out.
posted by eatcake at 3:29 PM on February 16, 2016

Whatever else you do with insulation you're going to want to caulk the living daylights out of it - go around windows, look for gaps in siding. We found it made an astonishing difference in drafts in our last house.
posted by leslies at 4:03 PM on February 16, 2016 [2 favorites]

If you remove old insulation - get it tested for asbestos before proceeding and hire a professional for that. That stuff is no joke.
posted by polychromie at 4:29 PM on February 16, 2016 [1 favorite]

Our house was built in 1951 and this year we replaced the original single pane windows with double hung and sprayed in 6" of insulation in the attic and our heating bills were literally cut in half. To save on insulation costs we bought the insulation at Lowes and got the blower free with the purchase of 15 bags. We actually ended up only using 12 bags and returned 3 but they didn't undo the free blower rental so that was nice. We also put foam insulators in our exterior outlets and replaced the weatherstripping on the doors to cut down on air leaks.
posted by julie_of_the_jungle at 4:51 PM on February 16, 2016 [4 favorites]

As an alternative to fiberglass, I used Roxul in my basement. It has more of a sponge-like consistency than fiberglass and is much easier to work with. A bit pricier than fiberglass though.
posted by LoveHam at 7:22 PM on February 16, 2016

Like Leslies says, caulking around window frames and baseboards. Sunrooms don't benefit much from insulation because windows don't hold in all that much heat (even double-glazed).

The biggest bang per buck is attic insulation and I'm a bit confused ....if you can't get into the attic, you'll need to cut an access panel in a closet or hallway ceiling (unless it's been re-done with cathedral ceilings?). They can blow the stuff in pretty cheaply and quickly from a truck. The attic needs to be ventilated and open to the outside. You just make sure it's small well sealed inside the house. The government guy who talked to me about it in our upgrade said that the paint on the inside of the house is considered a sufficient vapour barrier for older homes. I'd only do tha walls if it was part of a massive gutting, with new electrical/plumbing.
posted by bonobothegreat at 4:48 AM on February 17, 2016

Insulation doesn't necessarily make a surface airtight: closed-cell foam will stop air, but fiberglass, even with a paper facing, won't. Taking care of construction joints (wall corners, floor/wall joints, foundation/wall joints) is key.

For ideas, look at the Mass Save guide [pdf].
posted by Monday, stony Monday at 11:16 AM on February 17, 2016

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