Can I just replace the sawdust with insulation?

[Aunty]

It's not a bad idea to suggest using a bit more shavings since the only issue TS currently faces is excessive waste. This is a minor problem compared to what could happen if other solutions are attempted, and it can be partially resolved just by increasing the amount of shavings.

very interested in what problems TS might encounter if TS replaces shavings with cellulose?

 

[Boende45]

very interested in what problems the OP might encounter if they replace sawdust with cellulose?

No problems. However, the OP will get a better lambda value and less energy loss.

Wood shavings, we had those in houses when a cubic meter of oil cost 700 SEK.

 

[Davion]

very interested in what issues TS might face if TS replaces sawdust with cellulose?

What I referred to is what the professional carpenters I had in my home said when I discussed this exact issue about 1.5 months ago, as well as what the inspector from Anticimex said when I bought my current house.

I am speaking freely from memory, but the context was that changing an existing solution regarding insulation in a house, even from something similar to something similar, can lead to new conditions for moisture behavior (Cellulose insulation was also mentioned but suggested as a complement on top). I was advised by both parties to use the existing solution if the only noticeable issue was some heat loss.

Therefore, I don't know any concrete problems regarding the specific solution, but I primarily referred to the fact that two independent parties attest that sawdust is not an issue to use and that it is perfectly fine to add a bit more if desired rather than making major changes if no problems exist.

You wrote, "I think the thread generally has quite poor recommendations for TS. Recommending filling up with sawdust must be the worst solution for TS," and Anticimex and a construction company in Borås do not agree with that.

 

[nybyggarn3]

very interested in what issues TS might encounter if TS replaces sawdust with cellulose?

The replacement itself is probably risk-free, but lowering the temperature in the attic could become problematic. I would proceed cautiously.

 

[Aunty]

What I was referring to is what the professional carpenters I have had at my home have said when I discussed this exact issue about 1.5 months ago, as well as what the inspector from Anticimex said when I bought my current house.

I speak freely from memory, but the context was that changing an existing solution regarding insulation in houses, even from similar to similar, can introduce (cellulose wool was also mentioned but suggested as a supplement on top) new conditions for moisture behavior. Both parties advised me to use the existing solution if the only thing you could determine was some heat loss.

Thus, I know of no specific problems with the specific solution, but mainly referred to the fact that two independent parties testify that wood shavings are not a problem to use and that it is perfectly fine to add a little more if desired rather than making major changes if no problems exist.

You wrote, "I think the recommendations in the thread to TS are generally quite poor. Recommending filling up with wood shavings must be the worst of solutions for TS," and Anticimex and a construction company in Borås disagree with that.

First and foremost, I rank Anticimex very low on my list; they are known in the industry for concocting solutions to sell products, particularly their own.
Then, whatever a construction company in Borås says plays zero role, without knowing their education in the area.

Wood shavings were used in the past and are a poor solution for several reasons, that's just how it is.
Have you seen any new houses built with wood shavings as insulation? There's a reason for that.

If one is to redo, one should do it properly, and in TS's case, that means replacing it with cellulose.

 

[nybyggarn3]

first of all, I rank Anticimex very low on my list; they are known in the industry for making up solutions to sell products, specifically their products. Then, whatever a construction company in Borås says is irrelevant without knowing their education in the field.

Wood shavings were used in the past and are a poor solution for several reasons, that's just the way it is. Have you seen any new houses built with wood shavings as insulation? There's a reason for that.

If you're going to redo it, you should do it right, and in TS's case, that means replacing it with cellulose.

It's really easy to dump half a meter of cellulose. It makes the house warm and the attic cold. Then it molds like crazy if you're unlucky.

 

[Aunty]

It's very easy to add half a meter of cellulose. The house becomes warm, and the attic cold. Then it molds like crazy if you're unlucky.

No, why would it be like that?
You can work on more than one thing at a time, if there's any risk, you just have to manage it.

 

[nybyggarn3]

No, why would it be like that.
You can work on more than one thing at a time, if there's any risk, you just have to handle it.

Because you lower the temperature and continue to add moisture from the residence. Cellulose is good but not magical.

Edit: Handling the problem means shoveling out insulation and sorting it as combustible. I have an acquaintance who has made this journey.

 

[Aunty]

Because you lower the temperature and continue to add moisture from the dwelling. Cellulose is good but not magical.

Edit: Managing the problem involves shoveling out insulation and sorting it as combustible. I have an acquaintance who has made this journey.

Yes, but you don't automatically get a moisture problem just because you add insulation, right? And if you think there's a risk for some reason, you have to address it. There are, of course, lots of things you can do.

(Incidentally, who said you're adding moisture from the start?)

 

[GoC]

I put a couple of decimeters of loose wool up on the sawdust in my attic. It was 25 years ago on my house from '-46. The attic looks the same now as it did then.

 

[Davion]

First and foremost, I rank Anticimex very low on my list, as they are known in the industry for made-up solutions to sell products, specifically their own.
What some construction company in Borås says is irrelevant without knowing their training in the field.

Sawdust was used in the past and is a poor solution for several reasons, that's just how it is.
Have you seen any new houses built with sawdust as insulation? There's a reason for that.

If you're going to redo it, you should do it properly, which in TS's case is to replace it with cellulose.

I rank their certified inspectors higher on my list than some forum members, as well as the trained and certified professionals in a construction company.

You can have your opinion, and I fully agree that sawdust has disadvantages, that goes without saying. The claim that the worst advice TS received is to continue using sawdust when the only issue is a certain insulation value, is objectively wrong, regardless of your anecdotes against Anticimex or certified construction companies.

 

[b8q]

yes, but you don't automatically get a moisture problem just because you add insulation, right?
And if you think there's a risk for some reason, then you need to address it.
There's obviously a lot you can do.

(by the way, who said that you're introducing moisture from the start?)

In all houses, human activity creates moisture introduction. You cook, do the dishes, wash, shower, even exhale moist air!
This warm moist air rises, and if you don't have a vapor barrier in the ceiling structure, the moisture will reach the attic.
It's simply physics.

If it's too cold in the attic, the air won't be able to hold as much moisture, causing it to condense on the cold surfaces, typically the sheathing.
Again, simple physics that can hardly be argued against.

You can handle the problem in different ways:
- keep the attic warm
- install a vapor barrier
- ventilate the moist air before it causes damage (the problem then is what to replace the air with; sometimes the outdoor air is just as moist).

 

[Aunty]

I hold their certified inspectors higher on my list than some forum members, as well as trained and certified professionals in a construction firm.

You can think what you want and I completely agree that shavings have disadvantages, that goes without saying. The claim that the worst advice TS received is to continue using shavings when the only problem is a certain insulation value is objectively wrong, regardless of your anecdotes against Anticimex or certified construction firms.

what do you mean certified inspectors, how are they certified?
Then I'm wondering what kind of certificates the professionals in a construction firm have?
It's not exactly trained civil engineers who work at Anticimex if you thought so, they are salespeople.

The only problem with wood shavings isn't the lambda value, wood shavings have many problem areas.
There are many reasons not to use them anymore, so if you are laying in new, you definitely shouldn't use shavings.

 

[nybyggarn3]

I hold their certified inspectors higher up on my list than some forum members, as well as trained and certified professionals in a construction company.

You are free to have your own opinion and I completely agree that chipboard has disadvantages, that's obvious. The claim that the worst advice the OP received is to continue using chipboard when the only issue is some insulation value, is objectively wrong, regardless of your anecdotes against Anticimex or certified construction companies.

Yes, but you don’t automatically get a moisture problem just because you add insulation, do you?
And if you believe there's a risk for any reason, then it should be addressed.
There are obviously plenty of things that can be done.

(By the way, who said that moisture is added from the start?)

Now we're talking about a house from 1920 and not 2020. The house is built entirely without a vapor barrier
Therefore, all humid air will rise up to the attic. The thin insulation makes it relatively warm in the attic, which is an advantage. Spraying insulation in modern amounts will lower the temperature. The risk then is that it will cause problems.

 

[Aunty]

In all houses, human activity creates moisture supply. Cooking, washing dishes, doing laundry, showering, even exhaling moist air! This warm humid air rises, and if there is no vapor barrier in the ceiling joists, the moisture will rise into the attic. It's simply pure physics.

If it is too cold in the attic, the air will not be able to hold as much moisture, causing the moisture to condense on the cold surfaces, usually the roof decking. Again, pure physics that is hardly arguable.

Then there are different ways to handle the problem:
- have it warm in the attic
- install a vapor barrier
- ventilate the humid air before it can do damage (the issue then is what to replace the air with; sometimes the outdoor air is just as humid).

is exactly what I'm saying, if you believe it's a problem, then you'll have to deal with it. There are plenty of good ways to handle it depending on the risk.