retrofit insulation

Blown in cellulose is popular, but you can also blow in fiberglass or mineral wood or other materials. There is also a poured in foam which would probably be better, but likely more complicated. Now you really need only to insulate the exterior walls and roof as the party walls usually abut a heated space next door. However, you may need to assess if there is a wall cavity to blow insulation into. If not, you may be better off demoing the drywall and adding 2 or more inches of rigid insulation. Honestly I doubt it will make too much difference because you can put R-13 walls, but the windows are much of the wall area and they will be not more than R-5 and more likely R-3. The roof is where it makes the most sense to blow insulation in.

op, because i am getting ready to do some of this in my house, i have been doing a little reading and stumbled on an article on line by Bob Villa (this old house fame). he discussed the different ways to apply insulation after the fact and the different kinds that can be put in (“blown in” can mean different things). i am sorry i did not save a link (it was my bedtime reading), but it should be easy to google.

also, what i said about contractors and asking them questions. there are certain “trades” in the city (the unlicenced kind) that tend to draw a lot of people who could otherwise not succeed at anything else. these “trades” are often in areas that a lot of consumers do not know a lot about and they are often not the wysiwyg (what you see is what you get) variety so it allows some people to operate without really knowing what they are doing and in a way that they can hide their mistakes. they are also in things like this for one thing: money (where as craftspeople are very well in it for something else). and too often, they do a job and six months late r, issues arise.

as a contractor (and one who has had to source a lot of other contractors), this insulation industry seems to be one that can be a safe haven for people looking to make a quick buck. that is why i am suggesting you read and when you bring people in ask questions and see what answers you get. if you begin asking about moisture or condensation below the roof deck or what happens if you have a leak around a window and you have blown in newspaper clippings as ooposed to fiberglass mulch and they either do not know what you are talking about or look evasive or give you an answer that does not jibe with what you are reading, show them to the door. keep in mind, if this is their “career” they should have the answer right there with out having to ask someone else.

because of the problems that can result if moisture gets where it does not belong, this is an industry i would be careful with. done wrong, it could get pricey later.

one thing i notice about houses – and this is because i work on doors – if you have leaks or openings up top, stack effect will push air in at the bottom, and when i say push, i mean push. i often stand in doorways and feel drafts and sometimes i will ask the occupant if they have a fire place and if they damper is open. if you have fire places and you do not plan to use them, make plans to close them. it is not even a matter of heat going out them, it is the matter of the cold air coming in as the air leaves them. due to the stack effect, this kind of cycle works continuosly.

i am wondering how your finished walls are placed to the brick exterior walls. if the finished wall is placed on firring or sticked with 2×4’s, perhaps you can blow insulation in through holes cut in the space between the studs.

i am getting ready to blow and spray foam insulation into the spaces between the joists in my basement as we have a full size garage door that opens into the back yard. there are ways to do this without a lot of disruption. i am doing it to kill noise and for fire protection on exposed joists but it will have other benefits for us as well, slowing movement of air and loss of heat. perhaps something like this can be done at the top of the house, but before blowing anything in below the roof, talk to a pro (and not just some salesman who wants your money but someone who will tell you the truth and turn a job away if it is not the right thing to do) or wait for someone on here who has studied this to comment as there are moisture concerns at the tops of houses and under the roof deck and i am not sure what we can and cannot do.

this reminds me of somethihg else. In the house i live in, there is actually a large space between the roof and the finished ceiling. a cockloft. the temptation exists to insulate this but for the reasons i state above i will not. but also this: if the ceiling is not properly supported, if they treated it less like a structural element and more like a finishing element, it may not be able to hold a lot of weight. here where i lived they did not run 2×6’s to hold the ceiling. maybe 2×4’s and 2x4s are not designed to span anything. so they tie the center of the 2×4 grid to the roof joists with a single wire in the middle . someone over here blew insulation in and the wieght snapped the wire and the entire ceiling came down. be careful.

Even though insulation is not my thing, i am a contractor and when this stuff has to be done in my house i do it. the difference between me and you, in knowledge on this stuff is not a lot. as a contractor, i know the questions to ask people who i bring into my house to do work (and i weed the bad ones out fast; one or two questions) Wait for others to come on here with what they did under their roof decks and keep reading on the ‘net, about “blown in insulation” and “foam insulation” and how they get it in and moisture concerns and you will soon know a lot and better yet, if you bring a contractor in, you can put a few questions to them.

one last thing, i know you said you will not be doing the roof for some time, but when they do these roofs, they can put insulation under the membrane. i have had that done on commercial buildings, not so much for heat value, but to pitch the roof. if you can do your roof a little sooner and make the insulation wait a little longer, perhaps that is something to consider,