Bad odor in house from the '70s

[Speed254]

Hello!

We have recently moved into a house built in 1976 and we have a smell that sticks to clothes and hair.

We have traced the smell to the exterior walls, it can be noticed from outlets, among other things.

Now we have opened up a bit in the exterior wall to see how the sill looks. What do you think about it when you look at the photo? Is that moisture damage you see at the bottom?

 

[K. L]

I heard about some people who had mold in the house, that smell got into their clothes.

 

[Speed254]

I heard about some people who had mold in the house, that smell got into their clothes.

I don't actually think it smells like mold.

 

[Jonatan79]

Doesn't look like pressure-treated studs/sills. What is the layer in the walls? Is there plastic? Does the insulation smell?

 

[newbee]

I think it rather looks like the underside of the sill has been coated with something. Have you measured the moisture content in the sill?

 

[Speed254]

Doesn't look like pressure-treated studs/sills. What is the layer in the walls? Is there plastic? Does the insulation smell?

There is plastic against the inner gypsum wall, insulation, asfaboard, and some kind of paper that smells like tar or something similar.

 

[Speed254]

I think it looks more like the underside of the sill has been coated with something. Have you measured the moisture content in the sill?

Yes, I also think it looks like what you describe, maybe I need to take out a piece of the sill and examine it further. No, we haven't measured it, just exposed the hole.

 

[Jonatan79]

The risk is that there is trapped moisture due to the plastic. At that time, houses couldn't be built like they are today. There probably wasn't good ventilation either. There may also be moisture trapped due to an old water damage in the floor joists that stinks

 

[Ulltand]

I think it looks more like something has been applied to the underside of the sill. Have you measured the moisture content in the sill?

Agree, it looks like some kind of oil has been applied to the underside. Otherwise, it looks healthy imo.

 

[Ulltand]

The electrical conduit might be in the attic, and could the smell be coming from there.

 

[Speed254]

The wiring for electricity can be in the attic and the smell might be coming from there.

We only have the smell on the ground floor, it smells a lot by the entrance and there are no electrical outlets at all there. If you go up to the upper floor, it's like a different house.

I can add that the floor was recently replaced in most of the ground floor and the base looked good without signs of moisture damage. But the smell didn't disappear at all. We have also plastered and painted much of the interior walls. That made the smell disappear for a month but then it came back.

 

[Ulltand]

We only have the smell on the ground floor, it smells a lot at the entrance and there are no electrical outlets at all. Going up to the upper floor feels like a different house.

I can add that the floor was recently replaced in most of the downstairs, and the substrate looked good with no signs of moisture damage. But the smell didn't disappear at all. We have also skim-coated and painted a large part of the interior walls. That made the smell disappear for about a month, then it came back.

Did you have the smell before the floor replacement? How is the floor constructed?

 

[Speed254]

Did you have any odor before changing the floor? How is the floor constructed?

Yes, but it was worse before we painted and changed the floor.

The floor is now on bare concrete slab, the old wooden floor was laid on a mix of debris like old glued vinyl flooring that we sanded down to concrete.

 

[Ulltand]

Yes, but it was worse before we painted and replaced the floor.

The floor is now on a bare concrete slab, the old wooden floor was laid on a mix of debris like old glued vinyl flooring that we sanded down to concrete.

That sounds good and risk-free.

You become, like you, concerned about the sill. A sample doesn't necessarily show the whole truth. Is there any part of the foundation that might be more exposed to moisture?

Do you have mechanical ventilation in the house?

Air sampling can be done to analyze for solvents from building materials or microbial growth. VOC/MVOC. This way you can narrow down the problem and perhaps get ideas on what is causing the smell.

 

[Speed254]

That sounds good and risk-free.

As you mentioned, one becomes concerned about the sill. A test doesn’t necessarily reveal the truth. Is there any part of the foundation that might be more exposed to moisture?

Do you have mechanical ventilation in the house?

One can perform a pumped air sampling and analyze for solvents from building materials or microbial growth. VOC/MVOC. This can help pinpoint the issue and maybe provide ideas on what is causing the smell.

We don't have mechanical ventilation. When we bought the house, there were no air vents in large parts of the house, so we’ve drilled a few new ones to improve ventilation.

We've had mixed opinions from people working in the industry. Some have said without a doubt that it’s the sills smelling in our house, while others have said they don’t smell anything at all.

We don't want to waste a lot of time and money and still have the problem. But should we maybe take out some pieces and try smelling them? I think the asfaboard smelled a lot when we just took off a piece, but the smell has started to fade now.