older home: insulation or radiant barrier?

[Dan]

I have a 1950's house, with about 3" of blown cellulose in the attic (I assume none in the walls). After two sequential $250+ heating bills, I decided to address the insulatory nature of the home. My question is, without the addition of a ridge vent, would those of you in the know recommend installing radiant barrier or blowing in another 8" of insulation (not fiberglass). The costs appear to be the same (or assume they are), and I can only budget for one. Assume I would be doing either of the installations. One additional question involves painting the roofs underlayment with a ceramic/metallic paint marketed for it's radiant and insulatory benefits. Thank you in advance. - Dan

[Joseph Meehan]

I would add the 8" It will do far more in the long run for you. I would also suggest checking out the walls. If they lack insulation (in the 50's most if not all homes in my area would have had insulation) taking care of them will pay back quickly enough to make it worthwhile and you also gain comfort.

If you have questions about roof venting, I suggest you have that checked. However I would guess that if you don't see problems after 50+ years, your venting is not all that bad.

[Daniel Callahan]

Thanks. I agree about the walls and am trying to decide between foam or blown cellulose. The exterior is brick, so most likely I would access the walls from inside. Thoughts/experience?

[m Ransley]

Where do you live , what are your low temps. Blown in cellulose settles and any future leak will ruin it as it is paper. Fiberglass batts are best and R 50 is worth the investment for most areas. And many areas could use even higher R value. Foam in walls is good but how will you know if its been filled, and will it break your walls when it expands

[Joseph Meehan]

...

With my experience, the brick went all the way through. The plaster was directly on the brick (home about 150 years old). I built a new wall using

2x4s allowing for utilities and insulation.

[Daniel Callahan]

I live in Charlotte, NC. We just experienced 15" of snow, which is a lot for us. That being said, we are going in Spring and then muggy summer. Your comments about insulation are appreciated - thanks.

[m Ransley]

Dan, since you live in a zone 7 area R 50 - 60 would be great, it will also help in your air conditioning bills. you do have central air , yes, because summer heat rises, and i know the Carolinas are hot... Im in zone 5 we go to - 20- 25, i put in R 100, Remember minimums are just that the minimum so you dont go broke paying the utilities, before you cant pay the bank . people would if allowed, build houses without insulation, Its also the best investment you can make, as interest rates are low and gas and electric will always go up.

[Daniel Callahan]

R100!? Impressive. Thanks for the comments. For the easy of installation I probably will go with blown cellulose unless someone really convinces me off it. Dan