Pretty quiet around 637 Polk this week . . . until Friday. Seems that it is increasingly difficult to schedule subcontractors in a timely fashion because everyone is very busy and overcommitted.
But on Friday, the insulation guys arrived to apply the spray-foam insulation. The material they are using basically consists of two different chemicals that when mixed together – foam up and provide not only a great insulation value, but also seal up cracks and crevices to really help cut down on air infiltration. It was 2 guys in a big truck, but the inside of the truck was mostly 55 gallon drums and pipes and hoses. 
It was equipped so that both of them could spray at the same time – so there were two hoses run in through the front door and up into the attic spaces. They were both clothed in plastic suits and had respirators on and it was pretty hot up there . . . that is until the insulation was applied.
The chemical process as the two materials combine and react to each other put off a bit of heat, but once the foaming was done you could almost immediately feel the impact of the insulation on the inside of the house.
The walls will all get fiberglass batt insulation – because it is more cost efficient. The spray-foam goes everywhere else – the underside of the roof deck, the perimeter of the floor framing, the gable ends in the attic space, etc.
The spray came out of the nozzle almost like a thick coat of paint, but almost immediately it would foam up and grow to fill the depth of the cavity. Code requires R-30 for the attic insulation which would equate to about 10″ of fiberglass batts or blown-in on top of the ceiling. However you can achieve the same R rating with about half that thickness of spray-foam insulation.
The other great benefit is that it is applied to the underside of the roof deck so the attic space doesn’t get nearly as hot. With normal attic insulation, the batts or blown-in insulation are laid on top of the ceiling drywall, so it creates an blast oven in the attic – which anyone who has ever been in their attic in the summertime can attest to. And if you have your HVAC ducts in the attic (which most houses do), the ducts are having to overcome that stifling heat when trying to carry cool air to the rooms below. However with the insulation located at the top of the attic, the heat is kept outside and the attic maintains a much more tolerable temperature.
The spray-foam sticks to everything and creates a winter wonderland in the attic. Above is a photo of the main attic space over the Second Floor. Below is above one of the upper Bathrooms. Its too late to move anything now!
They are also spraying the cavities created where the floor joists sit on the Basement walls. This will provide great resistance from air infiltration there – which was not so great before we started this little project.
Finally they are also spraying under the cantilevered Master Bath to keep our feet warm in the winter.
In the meantime, to continue my obsession with quiet drain pipes, we’ve decided to add mineral wool under and around the pipes in the ceiling of the Pantry. 
We bought yet one more bag of mineral wool (that’s 9 bags in all) and I think that this will wrap it up. I have a little extra – if anybody needs some, just let me know.
The insulation guys will be back on Monday to put batts in all the exterior walls. The code back in 1980 only required R-11 insulation in the walls, but now it requires R-13. We originally planned to just leave some of the walls alone since they weren’t being disturbed for other reasons, but this week we re-visited the issue and decided to go ahead and pull the old drywall and R-11 insulation off the few remaining undisturbed walls and put in all new R-13 and drywall.
So we were back to the old days of demo! Drywall off, and then pull the old insulation down.
We tossed the insulation out one of the back windows – easier than carrying down all the stairs.
All the drywall went out the front door and then it was time to dispose of it.
I’ve lost count of dumpsters – but we’re filling up another one. The drywall contractor will be here soon – and that will probably fill this one on up.
The batts should go in on Monday – and we’re getting very close to time for drywall!
