Wednesday 13 December 2017

More insulation for our walls and roof

When we first moved into our home in Assen we were disappointed by the lack of insulation resulting in a high energy bill even with low indoor temperatures during our first winter.

We have now lived here for more than ten years. Each year we've done something which has improved the energy efficiency of our home, including this year when we inexpensively added more insulation to the top floor of our home. The result is that this winter our home is again a little warmer and also more energy efficient so more economical than it was before.

Two days of snow followed by warmer weather and rain and
we still have solid snow on our roof. The area under the red
square is where we made the most recent change. The area to
the left of the red square is a bedroom which we had already
insulated in a similar way a few years ago.
The roof
This year's improvement was quite minor: We added insulation to the ceiling above the top floor landing and staircase. This results in the first floor landing and ground floor entrance hall being better insulated than they were before. This job actually began in the first winter that we lived here when I quickly added some thin insulation panels to this area after seeing our first winter fuel bill. It continued a few years later when I doubled the thickness of that insulation but then remained as an unfinished job until the beginning of this year when we began the last part of it, stretched out over months because of other commitments, beginning by adding yet more insulation to reach a total thickness of about 10 cm, covering this with reflective and damp proof foil and finally hiding that with plasterboard (aka gipsplaten, gypsum board, sheetrock), sealant to fill the gaps and applying some paint. Actually, the job is still not quite finished. I need to paint again.

Anyway the process was simple and can be summed up in one photo:
10 cm of solid insulation above double sided bubble wrap foil which itself offers quite good insulation and reflects back energy otherwise lost due to radiation. Gaps in the foil are closed by reflective tape where there are joins. Wooden battens are installed to support the weight of the plasterboard sheets. It's quite important that there is an airtight seal as this prevents condensation from forming behind the insulation where it is cooler.
Also the walls
It's been five years since I last wrote about insulating our home but that's not five years of doing nothing. Another job which was completed a couple of years ago was taking apart the lower parts of the front and back walls on the ground floor of our home. I had long suspected that there was not much insulation inside these walls, and was pleasantly surprised to find that they were better constructed than I had expected. In total there was 4 cm of glass wool plus another 3 cm of polystyrene solid insulation bonded to an asbestos sheet which provides weather protection on the outside of the house to a height of about half a metre (we don't have any other asbestos so far as I know, except a fireproof panel on the door to the room with the central heating).

The existing fibreglass looked a bit sad, clearly it had been damp at some time, though there was no sign of any damage to the wood, all of which looks brand-new from the inside despite being 40 years old. The insulation was not very evenly distributed. I removed it and it was possible to see some gaps through which air could come from inside the house, the probably source of the damp which had discoloured the fibreglass. I sealed the gaps and all around the edges so that the wall is now both air and water tight and no further damage should be possible.

I then used the same double sided reflective bubble plastic here. It's the same double sided bubble wrap type foil as I later used in the ceilings upstairs. In this instance you can see it installed on the inside edge. On top of this I installed the existing fibreglass a bit more evenly than before. It had been discoloured but there was nothing wrong with it. On top of that there is now then another layer of reflective foil which helps to reflect out sunlight in the summer. There is a radiator mounted on the other side of this wall. The interior reflective material is intended to help to keep radiated heat inside the house.

Afterwards I re-installed the original polystyrene + asbestos outside panels, slightly further out than before because the thickness of the reflective foil has added slightly to the overall thickness of the wall. The asbestos is something I intend to dispose of in due course, but covered in paint and on the outside of the house it's not really a danger so for now it will remain until we think of a better alternative. Note the paintwork behind - one of the other problems with these sheets is that paint other than the original brown of the house seems to peel of its own accord. This has been repainted and now looks a lot better again.
Low cost improvements
Neither of these jobs cost much to do. The results of them are difficult to quantify, but thicker insulation and reflective materials to keep infra red energy within the house ought to be expected to bring improvements. We notice that even on cold nights the wall behind the radiator now feels warm rather than feeling cold so it seems that the reflection within the wall is helping. Even more obvious is that we keep snow or frost on our roof a lot longer than any of our neighbours do. Our immediate neighbour's home, featured in some of our photos because it's closest by, is far from the worst in this regard.

Neither of these two jobs was expensive to do. The materials (reflective foil, insulation, tape, sealant, glue, screws) are cheap. It required a bit of planning and took quite a few hours, but it's a reasonable DIY job.

A less inexpensive job
Last year we also had a problem with one of our windows. The seal had broken on an older double glazed unit in our front room, dating from the 1970s, and we arranged for this to be replaced by a new triple glazed unit:

The old glass looked misted up all the time because moisture was caught between the two panes. This is not a rainy day photo even though it looks like one.

The new triple-glazed HR++ panel before installation. It only covers a small percentage of our total glass area but at least this small percentage will perform far better than before.
With windows, the glass isn't the most expensive thing. Labour for fitting this new glass cost more than the glass itself. However this was not a job which I could have done myself as the glass was heavy and needed to be lifted quite high (it's the longest window at the top in our living room in the photos. This more expensive job simply couldn't be done by myself but we did need to replace the panel anyway so decided to pay the small extra cost for triple glazing over double glazing. Our thinking was this while this won't make a huge difference to our energy consumption nor even to our comfort (getting rid of the misty glass it's more of a cosmetic difference), it will at least make a small positive improvement. I estimate that the downstairs will leak energy about 5% less than before.

Measurements made with an infra-red thermometer show that when the outside temperature is -2 C and the inside temperature of our home is 17.5 C, the inside of the older double glazed panel is 9 C while the inside of the new triple glazed panel alongside is 14 C. Clearly heat loss with be much smaller through the triple glazed panel.

Our current plan is to replace other double glazed units with triple glazing as they fail. When we bought our home there was single glazing upstairs but we had that replaced some years ago.

Better insulation = a more pleasant home
Better insulation means a more comfortable home, less energy consumption, a lower carbon footprint, and lower bills. What's not to like about any of that ? Many effective treatments can be made

A white roof is an energy efficient roof ! This photo was taken later the same day as the photo at the top, after a little rain and slightly higher outside temperatures. All four homes originally had identical insulation but our home, the left-most of the four, benefits in quite an obvious way from the extra insulation we've added.

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