OK, there has to be a more economical way to do this. I have an older house with either no insulation or very old insulation in small amounts in a space or two. I would like to spray foam (closed cell) the ENTIRE house where ever possible. Now after getting some quotes by professionals to come to do the job and also looking at the DIY kits that come in what look to be basically propane drums I have come to the conclusion that neither is cost effective for as large a project as I have. Hiring a contractor would be great if I just needed a room or two done. The DIY kits are perfect for small projects or very small places. But to do my entire home using either would cost a fortune. There has to be a way to buy the same equipment the professions use but on a smaller less industrial scale to do the job myself. That way I can just buy a large drum or so of foam and will have the equipment do the job myself for the entire house. From what I can tell from searching the web the only two things you really need appear to be a paint sprayer machine (pump) and a proportioner machine that also heats the hose? Can anyone help educate me to see if this is possible or chime in on what my options might be? I have a hard time believing this is that difficult a thing to accomplish but rather just rare to do.