insulate next step... walls...

[maverick06]

I have a split level house built in about 1952. Its cold in the winter and hot in the summer. I put in R30 insulation in the attic over about an inch of rockwool and then about 7" of fiberglass (was at the top of the joists initially). So I am satisfied with the attic, it made a huge difference.

Windows are all moderately new, everything is doublepane and no notable drafts from them.

the exterior walls are so cold though, I think this really needs to be the next step. I have a friend in mass who did it to a much larger house for $3800 and the state paid for $2k of it.

I am looking into the best options here. And specifically if there are any PA programs to help fund this, I haven't found them yet...

I would prefer if this can be done from the outside. I have vinyl siding outside, assume iti would be easy to pop off a row and spray/blow in whatever. I am not sure what is best to do in that method, or where to shop around for contractors. The friend in Mass said it was highly regulated what insulation materials were refundable.

I am in media, pa (just outside of Philadelphia). Any comments would be appreciated.

 

[saewoody]

Being from CT, I don't know about any rebate programs in PA, but I do know that we did blow in insulation from the outside a few years ago and the improvement was amazing. Our house was a 900+ sq ft 1938 Cape with only an attic upstairs (no bedrooms). We went from heating that with 4-5 cords to heating the original house plus a full second floor addition and a 250sq ft addition off the kitchen with the same 4-5 cords. They do just what you said; pull of a row of siding and drill 2" holes and blow the insulation in, then fill the hole with a plug. Ours was done near the top of the wall as well as half way up. Well worth the money.


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[blades]

blown in dense packed cellulose or foam for walls. Recommend using a contractor very familiar with either for this job. Not a diy.

 

[velvetfoot]

They didn't put any insulation in the walls in 1952?

 

[EatenByLimestone]

They didn't put any in my 1946 cape. Having cellulose put into the walls made a huge difference in comfort. And the house is quiet too!

 

[maverick06]

the few wall cavities i have had to go into were empty, and the temperatures are quite cold on the walls.

 

[EatenByLimestone]

Oh, run any new outlets you might want on the exterior walls before they start!

 

[blades]

Ditto on interior as well

 

[woodgeek]

Yup. Wall insulation was optional in the 1950s around here. By 1960 some of the walls had fiberglass, but it was so expensive, they put 1" or 2" thick 'econobatts' in there (I think I have some of those).

Answering Mav's question: I got help from PA for an energy retrofit, and it was in the form of a low interest loan to cover 100% of the work, to be paid entirely by me. I think they charge me 1% interest over 10 years, and they paid the first 6 months (including principal), or something like that. Worked out to be an effectively zero cost to finance for 10 years, and that worked for me if the payback was less than 10 years...no opportunity cost, b/c there is no upfront charge, and the loan gets paid off from savings.

Of course, the state has to pay the loan agency an unspecified rate to offer these terms, and the program gets funded in a lump sum every few years by the PA statehouse. And then when the money gets used up, no more loans. The retrofit contractors go from feast to famine and back again....not the most efficient process.

I did mine like 4 years ago, and my neighbor more like 7-8 years ago (same terms). Maybe the statehouse will drop another bolus soon...I wouldn't bet on it.

 

[Circus]

blown in dense packed cellulose or foam for walls. Recommend using a contractor very familiar with either for this job. Not a diy.

I blew cellulose into a rental 25 years ago. It was easy and only a couple hundred dollars. The hardware store that sells the insulation rents the machine. Just blow insulation into the bottom hole of the wall til it spits out the top hole. Walls are a lot more pleasant than blowing cellulose in an attic. An hour of study and you'll be an expert.

 

[peakbagger]

I helped do a couple of homes years ago with cellulose. As Circus describes it was pretty simple, pop or drill the siding top and bottom and then blow upwards. The biggest hassle is renting a rig that is in good shape and finding a circuit that will take the load.

The cellulose is nice but foaming the walls is even more impressive (but expensive). It cuts sound transmission way down. I think the federal government pays for homes near landing strips to have that done. A friend had it done and with the air to air heat exchanger turned off, when you close one door from the outside you can feel another exterior door try to open. It pretty well eliminates any air infiltration. That with a window upgrade really quiets things down.

 

[venator260]

They didn't put any insulation in the walls in 1952?

My house was build in 1954. They put foil backed kraft paper between the studs and plaster, and that's it. I've insulated the kitchen/dining room and a bathroom so far (gut and redo everything). Big different in the temperature of the walls. I can look at my roof when it has snow and tell where I've improved the attic insulation as well (1.5 story, so the attic spaces are split up).

I'm glad to hear that blown in cellulose is a DIYable job. I don't really want to gut my living room, but I would like to insulate the walls. I'll be paying enough contractors over the next year (an excavator, a building contractor, and fireplace installer). Didn't want to have to hire another one.

 

[velvetfoot]

As far as retrofitting insulation, it seems better to have no insulation in a wall compared to some weak stuff.

 

[woodgeek]

If I were filling walls, I would want densepack cellulose for airsealing and no settling, and do NOT consider that to be a DIY job. An experienced pro will show up with a truck mounted hopper/blower, make short work of the job, and leave you no gaps anywhere.

 

[Ashful]

If I were filling walls, I would want densepack cellulose for airsealing and no settling, and do NOT consider that to be a DIY job. An experienced pro will show up with a truck mounted hopper/blower, make short work of the job, and leave you no gaps anywhere.

Exactly. The DIY jobs often leave the upper foot or two of wall cavity empty, after settling.

 

[velvetfoot]

How's foam nowadays?

 

[EatenByLimestone]

I had a foam company suggest and install the cellulose. They felt foam is best applied when walls were open. I had called them to inject foam into the walls. It was surprisingly affordable.

 

[Circus]

Exactly. The DIY jobs often leave the upper foot or two of wall cavity empty, after settling.

Looks like only a question of technique, and $10 of vinyl tubing.

 

[Ashful]

How's foam nowadays?

I used it in my barn/shop. Crazy tight, like pop-your-ears tight, if someone slams a door. My favorite choice for new construction, but it's not an easy retrofit unless you're planning a full gutting.

 

[semipro]

Looks like only a question of technique, and $10 of vinyl tubing.

I'd be a lot more impressed if Brad did that without the benefit of see-through walls.
Your point is valid though. Technique makes a big difference.

 

[Brian26]

I was surprised when I ripped into a wall in my 1958 built house to find 2 inch insulation bats. I may have it tested as some online research suggests it probably contains asbestos but nobody seems to know for sure. Its behind the walls and sealed so I am not going to worry about it. I will say though that its works really well considering how old it is and back then I am assuming insulation was kind of new. Based off using my FLIR it seems to be insulating extremely well on the exterior walls.

Its Red Top brand by US Gypsum.

 

[maverick06]

well i have about 8 contractors which do this type of job. many are injection foam, some are cellulose. at least one is clear that its dense pack, not so sure about the others. now to get some quotes and decide whats better, foam or dense packed cellulose. I guess the latter, but am not really sure...

 

[woodgeek]

I think foam is ok in moderation when you've got a special application (like a rim joist or need a lot of R in a very thin space), but there are technical things that can go wrong, leading to shrinkage (and loss of performance) or offgassing odors.

I am on the fence re the safety of the chemicals offgassed by the foams....it seems poorly regulated with a lot of BS like 'its made of soybean oil', when it is 10% soybean oil and the other 90% is polyurethane. And cavity fill (as opposed to spraying an open cavity) seems like it is tricky to get right.

While I would be fine to have a (warrantied) outfit do a small area of my house (and hope to pull the trigger later this spring, probably with Amerifoam, in a below grade application) I would balk at doing the entire house exterior walls with cavity fill foam.

Densepack cellulose is totally where its at, cheap, very green and zero outgassing. A good install is all about operator skill and experience...find someone that has been doing it for a while. I had some good densepack cellulose guys at Orange Energy work on my house. Only issue is do you get the stuff with sulfate flame retardant or the slightly more expensive stuff with borate flame retardant? They say the sulfate is corrosive and can attack your wiring....after a long period of time. I don't think its a big deal, neither material is particularly toxic. After my densepack work there was a little gray dust around, that had a slightly acrid smell. When the dust was gone after cleanup, the smell was gone too.

 

[semipro]

I share the concern of others related to shrinkage and out-gassing of sprayed foam.
Properly installed dense (even medium) packed cellulose has a compressive springiness to it that I like as far as long term air seal maintenance.
I packed cellulose in various cantilevered floor portions of our house using a big box machine and was impressed with the density I got. I later had to remove a soffit board below the packed cellulose for unrelated reasons and was impressed at how much pressure the packed cellulose was exerting on it. It seemed far more than he weight of the cellulose alone.
If I had work done by others I'd want verification of their work using an IR camera. Unpacked voids readily show up using IR. I'd expect a seasoned installer to do this as part of their install.

 

[blades]

Please not that the rental machines do not, for the most part, supply the correct pressure /velocity/volume ( I forget the numbers, easily found on the net) for enclosed cavity work like existing walls ( dense pack). They are meant for open areas like attics. So that said ask any contractor what he/she uses for walls vs attic- that will tell the tale quickly if they are honest. My current place is 90% brick -therefore most of it if not all would have to be done from the inside - just can't go popping 2" holes in the brick work - most contractor quotes should include restoration of the exterior / interior wall- painting would generally be left up to you.