Insulating the last cellar

We moved into the house in February 2015, after about four years of heavy renovation work, but due to exhaustion, there was one cellar left uninsulated: the one under our living room. Our first winter in the house was relatively mild, so it wasn't so bad. But the winter of 2016/17 was bitterly cold, and we really noticed that the floor of the living room was much colder, and the cold crept in. Unfortunately, due to shoulder problems at the time, I could in no way do any overhead work, so we sealed up the cellar door to reduce the ingress of cold air, and lived with it.

This year, with the arm again movable, I decided enough was enough, and it needed to be done before the really cold weather comes again. After considering several options, from Rockwool to Styrofoam, I decided on a method that had relatively minimal effort, but also probably the most effective, using cellulose-based insulation, like our roof.

To do this effectively, the cellar ceiling had to be as airtight from underneath as possible, essentially creating a big bag, stuck to the walls, that would be later filled with isofloc. To start this, I plastered the top 15cm of the walls to ensure a smooth surface around the perimeter. An apron of breathable damp-proof membrane was glued around the perimeter, using a special sealant. This would form the sides of the "bag".

Once dried, a framework of 4x6cm timbers was then suspended from the oak beams, to a depth of about 12cm below the ceiling. This time, I used Justierschrauben (adjustment screws), which negated the need for planing blocks of wood to precise thicknesses to achieve the desired height, which is what I did in the other cellar, and under most of the floors, so I was glad to avoid that again!

The membrane was then attached to this frame, and the apron folded up and all seams taped closed, to form a single, sealed unit, and laths screwed to the initial framework, to provide support and something to attach the final ceiling finish to (not yet decided).

This alone already made a difference in the living room, as air couldn't move so easily up into the living room.

I'd taken a half day today, after agreeing with a local carpenter earlier this week that he'd come at one o'clock with a machine to blow the cellulose insulation into the void. He turned up at 1:30 to say he didn't have enough material, and asked if  we could do it in a week. This has pissed me off, as he said he had enough material, clearly didn't check, and could have gotten it even today from a nearby supplier. We reckon he's busy on another site, but I would prefer honesty. So much for German efficiency, again! I guess I got a long lunch break out of it.

Maybe next year we'll do something more with this room. The plan is to move my beer and cider cellar into here, as I need more room for barrels and fermenters, and maybe a table for when friends come around.

Anyway, let's see how it looks in a week's time.