Mats Bengtsson

Isolating the house

Mats Bengtsson mib over the years

The isolation of the house is not too good

The house is built mainly from lightweight concrete and with the outside consisting of bricks. Parts of the house has a thicker isolation than other parts (the garage and the two rooms closest to the garage has thinner walls than the rest of the house).

Inside the walls, there is an air gap between the outer layer and the inner layer. There is not any other isolation in the walls than this.

So isolating the walls would lead to a drastic reduction of heating costs. But doing it is not that easy:

  • Isolating from the inside would mean leaving the original walls colder than today, and I am doubtful that is a good thing.
  • Isolating the outside means redoing the outside brick wall, too much cost and work
  • Isolating the air gap between the walls is an option, but again I see huge risks that it does not turn out too well

Isolating the loft is an option we are aiming at

The loft is also badly isolated, and there I see a much easier starting point. Today the loft consists of sawdust isolation, which has been improved with a thin layer (10 cm) of glass wool. The house is built in a nice charming way, but the disadvantage is that I do have two different roof parts, and the second attic parts (the one above the garage and the two rooms closest to the garage) is not accessible in an easy way. I am thinking of cutting into that attic through one of the rooms, in order to get to isolate the roof.

Isolating the main loft is a lot easier. The only thing I am contemplating is the need to use plastic isolation between the loft and the house. The common knowledge in Sweden is that you should always use plastic as isolation between the warmer and colder part, to assure condense is dealt with in best possible way. But since the house has been built without such plastic, I am uncertain that it will be the best solution.

Besides that, the option is easy: increase the height of the beams on the loft, and place isolation between those beams. I would like an isolation that does not have the same problem with mold as glasswool does, and cut paper seems to be a good option here, also being a solution that fits the house (the original sawdust isolation and the thought new cut paper comes from a similar environmental base).

We started with isolating all places with a draught

There was a lot of places in the house where there was draught. Most notably, and naturally, between windows and the window frames, and between doors and the door frames. But there was also two doors to the porch where the doors themselves where not very good, and there was a draught through the doors themsleves (they consists of only one layer of wood, and the draught was between those woods).

Isolating between windows and window frames and doors and the door frames on the inside was easy. Just buying isolation material and bracing it to either the frame or the door or the window.

Since we were isolating draughts, we intentionally added some fans to the house

With the draughts going away, and with no heat from the old oil furnace creating a flow throw the house with the aid of the heat in the chimney, we decided to put in some fans in the house. We added the first three fans in the wet areas of the house:

  • Small toilet, blowing air out
  • Bathroom, blowing air out
  • Wash room, blowing air out

Through this, we made sure to press moist air out of the house, and saw to that there was a need for new air coming into the house. The house was built based on the same principle (but driven through the heat of the chimney which is no longer in use), so there was already a number of fresh air inlets where the new air enters into the house.

Later, we added a fourth fan, in one of the wardrobes on the upper floor. There is four wardrobes built close to each other. We have added air flow holes between all these, and a fan in the last of the four wardrobes leading the air out. Thus, assuming the air needed to replace the air going out through the fan to be leading to an air flow through the other wardrobes, through their air ventilations

Treating the draught in the porch door was interesting

The draught in the door was a lot harder. The problem could be said to consist of three things, out of which we elected to treat only two:

  • There was a lack of isolation in the door, making heat to dissipate out
  • There was a draught in the door making the heat dissopation quicker and the draught a comfort problem
  • The door looked ugly and was hard to open and close

The part of the isolation of the door is something we have elected not to treat yet. The solution would be to buy a new door. But it seems that every time I try to estimate what the profit of buying a new thing will be compared to the cost of buying it, the pay back time seems to lie around or a bit above 10 years. This makes all such buys profitable, but doing too many of them, means a much higher cost during the first ten years.

Taking care of the door was one of our first little more advanced home wood projects. We took the door literally apart, and then cleaned all the old wood down to wood clean, and then put the door back together,. This time securing the corners with plugs through the door (to make it square and stable), then we filled the holes with wood filler, and finally painted it.

The end result was a neat looking door, with no draught.


Never trade stocks without having tested your system. In fact, most trading systems are not profitable if tested over many stocks. Full story...

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