Wooden house from 1939 - how is it constructed?

[putte82]

Hello!

I am wondering how this house might be constructed with a focus on the exterior walls concerning load-bearing and insulation, air gap? I'm not very knowledgeable about such old houses. It was built in Västernorrland.

 

[lofe]

I guess on plank walls that might have some sawdust as insulation. Then it looks like it has been additionally insulated externally at a later time since the windows are set a bit far in and the roof overhang looks a bit short.
Regarding load-bearing capacity, I don't know.

/Johan

 

[putte82]

40,000 kWh per year for heating and hot water. +5 annual average in the area. Building area 130m2.

 

[Chrissofsweden]

Didn't they generally make shorter eaves in the past?

 

[thomas33]

An image from the Energy Agency's brochure "Att tilläggsisolera hus – fakta, fördelar och fallgropar" showing an example of the construction of house walls at different times:

 

[justusandersson]

I agree with lofe. Certainly 3-inch tongue-and-groove plank in the exterior walls. Additionally insulated in the 1970s with 70/95 mm mineral wool. A total insulation value equivalent to 95-120 mm mineral wool, but with better thermal properties due to the plank's higher heat capacity. To reduce heat consumption, measures elsewhere are more important. The load-bearing capacity of the exterior walls doesn't need consideration as long as the house is used as a residence. The floor joists are probably a bit wobbly since 3x7 inch floor joists were often used. No risk of breaking but too much deflection.

 

[bakterie]

I also agree that it is likely a plank frame. We have a house from 1933, which has not been externally insulated, so the original facade is still there. In our case, it looks like the following, from the planks outward:

1. Plank
2. Some form of wind barrier.
3. Narrow vertical battens, cc approx. 20cm (i.e., air gap).
4. Slightly wider horizontal battens with a few centimeters in between.
5. Rendering (i.e., reed mat, chicken wire, and plaster)

You probably have to look behind the added insulation to be sure about this particular house.

 

[justusandersson]

Rendering was extremely common in the 1930s and 1940s. To understand the wall's construction, you can start by taking a measurement with a folding ruler in a window opening. Measure from the outside of the outer panel to the inside of the wall. Indicate if you include the covering lath in the measurement. A common treatment of the inside was after the plank framework: split panel (common boards on the diagonal split with an axe after installation), rörning (i.e., reed mat), and plaster. A rendered and additionally insulated plank wall with plaster also on the inside should have a thickness of about 23+23+70/95+20+25+25+75+25+15+20=321/346 mm.