Claystone - insulation value?

[13th Marine]

Congratulations on the new home!

What is the purpose of your U-value calculations?

Thank you.

We are trying to decide if we think it's worth renovating or if we want to demolish and build new.
And if we choose to renovate, we want to add additional insulation to the walls in some way.

 

[Oldboy]

It is important that the walls are dry. If they become damp, they insulate significantly worse.

 

[jawen]

It is important that the walls are dry. If they become damp, they insulate significantly worse.

The lambda value of the walls is already so poor that surface moisture will not affect it. Heat leakage from inside during autumn/winter/spring will also "dry" the walls continuously.

 

[Microkatten]

Thank you.

We are trying to determine if we think it's worth renovating or if we want to demolish and build new.
And if we choose to renovate, we want to add insulation to the walls in some way.

Ah ok, that's a big decision to make with many aspects!

The choice between building new and renovating is largely a matter of lifestyle and whether you want to renovate based on the house's conditions.

Adding insulation to a clay brick house is very low on my priority list, mainly because the effect is likely to be minimal, especially compared to other measures such as choice of heating system, sealing drafts, and insulation improvements in the foundation and roof. The economic and aesthetic cost can also be high.

We live in an old clay/timber-framed house and have chosen to remove all external modern additional insulation and just ensure that the facades are in good condition, windproof, with a minimal additional insulation of 45 mm. One of the facades is still unrenovated and basically uninsulated, except for the frame.

Planning renovations in an old house can also be risky before you've lived in it. The risk is that you spend money on the wrong thing.

Feel free to stop by if you want to discuss more about renovations of old clay houses vs building new. 😀

 

[jawen]

An additional insulation on a clay stone house is very low on my priority list, partly because the effect is likely to be minimal

The effect is likely to be minimal you say, despite the fact that additional insulation in all types of houses individually provides the most in terms of building energy needs.

I wouldn't want to take advice from someone who reasons like you, as your knowledge in building science seems low.

 

[13th Marine]

Ah ok, it's a big decision to make with many aspects!

Really!
That's why I'm gathering as much information as possible.

The choice between building new and renovating is largely a matter of lifestyle, and whether you want to renovate based on the house's conditions.

Definitely, we're wavering back and forth on how we want to proceed.
Then there are more buildings on the property, so there will be renovations to do regardless 😅

Adding insulation to a cobblestone house is very low on my priority list, partly because the effect is likely to be minimal, especially compared to other measures such as choice of heating system, sealing drafts, and insulation improvements in the foundation and roof. The financial and aesthetic cost can also be high.

We are trying to decide what paths forward are available so that we don't make foolish decisions at the start.
Any additional insulation would only occur after we've made the whole house habitable.

We live in an old cob/half-timbered house and chose to remove all external modern insulation and just make sure the facades are in good condition, windproof, and with minimal additional insulation of 45 mm. One of the facades is still unrenovated and basically uninsulated, except for the structure itself.

What kind of additional insulation have you chosen then?

Planning renovations in an old house can also be tricky before you've lived in it. There's a risk of spending money on the wrong thing.

Yep!
Our idea right now is to settle in a bit before we choose a direction, there are plenty of projects to keep us busy in the meantime.

Feel free to stop by if you want to discuss more about renovating old cobblestone houses vs building new. 😀

Thank you for the offer! It's not impossible that we might consider stopping by 🙂

 

[Oldboy]

The lambda value of the walls is already so poor that surface moisture will not affect it.
The heat leakage from inside during autumn/winter/spring will also "dry out" the walls continuously.

Oh, the moisture content does have a significant impact.
Dry clay brick with 5% moisture content has a lambda value of about 0.19 W/mK.
Moist clay brick with 20% moisture content has a lambda value of about 0.43 W/mK.
That's more than a halving of the lambda value. It indeed has significance.
Furthermore, if you compare with solid wood which has a lambda of about 0.14, a 50 cm dry clay brick wall corresponds to a 36 cm thick log wall.
Moreover, heavy solid walls have an advantage over light wood & mineral wool insulated walls as they even out temperature variations throughout the day.

(Lambda values for clay brick with different moisture content according to a scientific study published in American Journal of Applied Sciences 2020, https://thescipub.com/pdf/ajassp.2020.50.55.pdf.)

 

[Microkatten]

The effect is likely to be minimal, you say, although additional insulation in all types of buildings individually provides the most in terms of the building's energy needs.

Someone who reasons like you, I would not want to take advice from, as your knowledge of building science seems low.

It is entirely optional to choose who you want to take advice from. I wouldn't take advice from someone who wants to put 2 dm of expanded polystyrene on an old clay brick house and rebuild the roof.

You seem to be the type who always knows best and everyone else is an idiot, and I don't waste any time on such people. You are now added to my ignore list.

 

[Microkatten]

That's why I'm gathering as much information as possible

Good strategy! 😀

What have you chosen for additional insulation then?

In the end, we chose framing with hemp. We also considered other materials and constructions, including hemp-lime and wood fiberboards.

 

[13th Marine]

Good strategy! 😀

In the end, we chose a framework with hemp. We also considered other materials and constructions, including hemp lime and wood fiber boards.

On the inside then? 🤔

 

[jawen]

You seem to be the type who always knows best and everyone else is an idiot, and I don't waste my time on such people. You are now added to my ignore list.

Good!

If you can't even understand the technical aspects of a construction's assembly, then you shouldn't even be dealing with this. And if you don't understand that any additional insulation used can ALWAYS make the house facade look as it does today, then no one can help you.

 

[13th Marine]

Oh yes, the moisture content does have a significant impact.
Dry clay brick with 5% moisture content has a lambda value of about 0.19 W/mK.
Moist clay brick with 20% moisture content has a lambda value of about 0.43 W/mK.
That's more than a halving of the lambda value. It certainly makes a difference.
Moreover, if you compare it with solid wood which has a lambda of about 0.14, a 50 cm dry clay brick wall is equivalent to a 36 cm thick log wall.
Additionally, heavy solid walls have an advantage over lightweight wood & mineral wool insulated walls as they even out temperature variations over the day.

(Lambda values for clay brick with varying moisture content according to a scientific study published in American Journal of Applied Sciences 2020, [link].)

Interesting, the question is whether those figures can be applied to our Skåne clay brick, as it's a third of the figures I found 🤔

 

[jawen]

Oh yes, the moisture content indeed has a not insignificant impact.
Dry clay brick with 5% moisture content has a lambda value of about 0.19 W/mK.
Moist clay brick with 20% moisture content has a lambda value of about 0.43 W/mK.
That's more than a halving of the lambda value. It certainly matters.
Furthermore, compared to solid wood which has a lambda of about 0.14, a 50 cm dry clay brick wall corresponds to a 36 cm thick log wall.
Additionally, heavy massive walls have an advantage over light wood & mineral wool insulated walls as they even out temperature variations over the day.

The study highlights Nigeria's adobe soil & it won't be the same as Swedish clay brick/bricks.
The building material adobe block is also made from Nigeria's unburnt sand-mixed clay, water and straw/fibers that are sun-dried, so comparing with Swedish "clay mixtures" becomes incorrect.

To achieve higher insulation values, air must be introduced into the material, so their sun-dried straw helps a great deal & perhaps also the technique in their mixtures of this.

A Swedish clay wall without straw likely resembles our bricks more in terms of insulation values, and as the original poster’s approximately 60 cm thick facade wall in autumn/winter/spring will have "large heat losses," the walls will also remain dry. (the heat seeks outward through the construction & always tries to equalize temperature by natural laws)

 

[13th Marine]

The study highlights Nigeria's adobe soil & is not the same as Swedish clay brick/brick.
The building material adobe block is also made from Nigeria's unburnt sand-mixed clay, water and straw/fibers that is sun-dried, so comparing it with Swedish "clay mixtures" is wrong.

To achieve higher insulation values, air must enter the material, so their sun-dried straw helps a lot & perhaps also the technique in their mixtures of this.

A Swedish clay wall without straw is probably more similar to our brick in terms of insulation values, and since TS's approximately 60 cm thick facade wall in autumn/winter/spring will have "large heat losses," the walls will also remain dry. (heat seeks outward through the structure & according to natural laws always tries to equalize temperature)

However, I interpret it as the measurements were made on pure clay.

 

[jawen]

However, I interpret it as the measurements were made on pure clay.

A few lines from the study.

Demir (2008) showed that sawdust, tobacco residues, and grass can be used to improve the thermal and mechanical properties of adobe bricks. The insulation capability of the brick increases with increasing porosity of the clay body. Additions of organic residues were found to be effective for pore formation in the clay body and the clay retained acceptable mechanical properties.

Fiber-reinforced brick houses result in a temperature that is 56.3% cooler than concrete brick houses in summer and 41.5% warmer in winter.

In hot countries, this is beneficial for "poor people" & has many good properties. But in the Nordics, the "problems" & climate are completely different.