Suspicious sills (again).

[shadowfire]

I'm renovating a house that has had problems with moisture, mold, bad smells, etc. It's been going well so far, and I'm now on the last part of the crawl space when I made a new discovery.

The sill plates become darker and darker the closer you get to the wall and are really black. I'm not sure if it's rot that has set in because the wood itself feels hard. Is there any treatment besides cuprinol that was used in the 60s to protect sill plates?

It almost looks like creosote-treated railway sleepers/telephone poles...

 

[magnu]

If it's creosote, then it's basically as bad as mold.
I'm not sure, but I'm fairly certain that creosote should absolutely be avoided indoors.

Pressure-treated sills also risk smelling, even if they don't rot, but you probably already knew that.

But stick a knife in the sills and make your own assessment of how good the wood is.

 

[shadowfire]

If it's creosote, then it's basically as bad as mold. I'm not sure, but I'm fairly sure that creosote should absolutely be avoided indoors.

Pressure-treated sills also risk smelling, even if they don't rot, but you probably knew that already.

But put the knife into the sills and make your own assessment of how good the wood is.

Wondering how to identify the material/substance. Hmm, old telephone poles, are they creosote-treated all the way through so the wood is black throughout?

It's not pressure-treated and not Cuprinol either, as that would have been greener.

Starting to get the hang of fighting suspicious building materials, but I haven't come across wood this dark before.

 

[shadowfire]

Have you drilled out samples from the wood and the dark part is on the surface, i.e., it is painted on with some kind of substance.
I thought it smelled like charcoal or an old timber house when I started drilling it out. Reminded me of tar, quite a pungent smell.

We'll see how the scent samples feel in a couple of days.

 

[jzz]

Shadowfire: That's what some of the beams look like in my crawlspace too. The inspector who checked the neighbor's house mentioned brown cuprinol. However, my dad thinks it's the asfaboard that has stained them because it was damp there once upon a time. Does anyone know if asfaboard stains at all?

In my case, the beams are only superficially discolored/treated but still rock hard.

 

[shadowfire]

Shadowfire: That's how some joists look in my crawl space too. The inspector who checked the neighboring house talked about brown cuprinol. My dad, on the other hand, thinks it's the asphalt board that discolored it because it was damp there once upon a time. Does anyone know if asphalt board discolors at all?

In my case, the joists are only superficially discolored/treated but still rock hard.

Yep, I have now done smell tests on several of the parts. It's only certain sills that are brown and it's only superficial. Everything points to it being brown cuprinol. The smell tests didn't release any particularly dangerous odor either, a certain cuprinol smell appeared, but neither mold nor anything else. I have replaced a couple of parts now that I thought were a bit "unsightly" and that were easy to replace. The rest stay because I have a good crawl space otherwise with low humidity (oversized dehumidifier).

Here's how a part that I threw out looked... in the picture, you can see where I took smell and drill tests.

 

[pbengtsson]

It looks exactly like my 1960s Anneberg house. The floor insulation left much to be desired and there was tar paper throughout the subfloor. I tore out my joists even though there was nothing wrong with them, but I needed more stiffness.

In my case, I thought the black came from dirt as it was well ventilated in the floor in combination with the paper. The part that was cuprinolat was the sill.

 

[ansgar46]

Old thread, sorry
But what are luktprover?

/Janne

 

[KnockOnWood]

Old thread, sorry
But what are smell samples?

Go out into the fresh air and breathe in through your nose and out through your mouth a few times.
Then go inside and smell the object by breathing in through your nose.
What does it smell like?

Of course, it requires that you have a normal sense of smell or better.

 

[shadowfire]

Go out into the fresh air and breathe in through your nose and out through your mouth a couple of times. Then go inside and smell the object by breathing in through your nose. What does it smell like? Requires, of course, that one has a normal sense of smell or better.

Unfortunately, it's not that simple. The brain and sense of smell have the ability to filter out certain scents or distort them, which complicates the whole thing. It's not enough to breathe fresh air and go inside to smell something to have a reset sense of smell. It usually takes at least 24-48 hours in a different environment to reset the sense of smell.

This is exactly why a person with poor hygiene doesn't notice that they smell bad, because the brain and sense of smell have filtered out that odor so it "doesn't exist" in that person's world. Just like people in sick buildings often don't notice that their clothes are odor-contaminated – while others can smell it immediately. In the same way that you can "do number two" in the bathroom at ease without minding the odor, while if someone else has done number two in the same bathroom, you might think it smells horrible – even though you've produced similar feces.

However, I've discovered that the sense of smell is temporarily reset by vibrations in the skull, which is achieved when I brush my teeth with an electric toothbrush. Funnily enough, I notice smells then that I didn't detect before (and it has nothing to do with oral hygiene, but comes from the house).

 

[shadowfire]

Old thread, sorry
But what are smell samples?

/Janne

Smell samples are done in several ways, either by taking a piece of material physically, like insulation, or by milling out a piece from a sill and placing it in a bag. Preferably double bags. Then it is sealed and left to develop for a while before opening and smelling the contents. When dealing with sick buildings, it is necessary to open the contents elsewhere (or ask a friend who does not have a sick building to smell for you). The risk is otherwise that your own sense of smell has already filtered out that particular smell, so when you smell the material it smells fresh even though it is smell-contaminated.

Smell samples are also done by taking, for example, newly washed fabric (without fabric softener or detergent, but washed at 90 degrees) and hanging it in various spaces. Then let it hang there for 7-10 days or more. If there is a smell source that contaminates textiles and organic materials, the fabric pieces will absorb the smell. Then do the same by putting them in bags, maybe labeling which room they were found in, and opening them a few days later in a different environment (or ask a friend to try).

 

[KnockOnWood]

Breathing fresh air and then going inside to smell something is not enough to have a reset sense of smell. It usually takes at least 24-48 hours in a different environment to reset the sense of smell.

Yes, you are of course right!
But I was mostly thinking about the thread creator's disassembled and thrown-out wood pieces.

I used to do that, the first few years in our new house, asking visitors if they noticed any smells in our new house. Especially since we ran the ventilation at quite a low level.

 

[MagHam]

Yes, it takes several days for the sense of smell to "reset"
In addition to the villa we live in, we have a vacation home. When you travel between them and arrive at either place, you can sense that a smoker lived in the vacation home 10 years ago. At home, we notice that there have been dogs.
It seeps into the walls and can't be cleaned away. Sealing paint and new surfaces everywhere might gradually remove it.

 

[seniorkonsult]

Shadowfire: That's how some studs look in my crawl space too. The inspector who inspected the neighbor's house talked about brown cuprinol. My dad, on the other hand, believes that it is the asfaboard that has stained due to moisture once upon a time. Does anyone know if asfaboard stains at all?

In my case, the studs are only superficially discolored/treated but still rock-hard.

Asphalt board does not stain but can be affected by mold in a crawl space. Additionally, air blows right through them. Remove a piece of the wood, put it in a plastic bag, and ask, for example, Anticimex what it might be. If you have the sample in a bag, it will smell after a while.

 

[shadowfire]

Yes, it takes several days for the sense of smell to "reset"
In addition to the villa we live in, we have a holiday home. When traveling between them and arriving at either place, you can feel that a smoker lived in the holiday home 10 years ago. At home, we notice there have been dogs.
It lingers in the walls and cannot be cleaned away. Seal painting and new surfaces everywhere might remove it eventually.

A thorough ozone treatment can help if you turn off the ventilation or minimize it and go on vacation or something else at the same time. For several years I've used an ozone generator in my sick house specifically to sanitize and kill passive odor sources, i.e., odor-contaminated materials.