Hello, all. My home is in Maryland, and was built in 1963. The style is “mid-century modern”, or what we used to call a “split level”. The main living area has a rolled roof (which is light grey in color to reflect the sun) with very little slope; that roof rests directly on sheathing that is in turn nailed to the ceiling rafters. There’s nothing even vaguely resembling an attic. The rafters are, I think, 2×8, and they span the living room and kitchen area – a distance of about 25 feet, with a width of around 30 feet.

The ceiling is relatively high – 13 feet at one end of the room, down to 10 feet at the other end – and that directly reflects the slope of the roofline.

There is no insulation in that ceiling, and in the summer, that room heats up and forces the A/C to run constantly in what seems like a losing battle to cool that space. When I called a contractor to inquire about having insulation blown or sprayed in, he quoted me a price of about $5000 (for blown cellulose insulation only, holes in the drywall plugged, but no finishing work)

In thinking about this, I’m wondering how crazy it would be to simply drill a series of small (1/4″ or so) holes every 18 inches or so on a line between the rafters and spray expanding foam (maybe the fire-stop variety, or the extra-expanding flavor) through those holes. My goal is to get some R-value in there without having to rip my ceiling to shreds. I know it’s not ideal, but it would seem efficient and at least marginally effective.

To me it seems crazy that there isn’t a long, thin tube that could be threaded through a hole at one end of the ceiling and then pulled out, spraying a layer of insulating foam behind it. I’ve been told that no such thing exists. I get that it would be a specialty market, but I don’t see a reason why it couldn’t be done relatively easily with existing equipment. Is there something I’m missing? Many thanks in advance your collective wisdom.