It looks strange. I also think it looks like it's been burned, but that's hardly the case. It's not that the large "sotflagorna" on the underside are overwintering butterflies? I have lots in the ceilings of my farm buildings.
Anyway, with black around the eaves and attic hatch, it feels reasonable to suspect many years of leakage of warm, humid air from below. Perhaps the sealing between the outer wall and attic floor is non-existent?
Is it a 1&1/2-story or 2-story house?
What type of ventilation does it have?
Anyway, with black around the eaves and attic hatch, it feels reasonable to suspect many years of leakage of warm, humid air from below. Perhaps the sealing between the outer wall and attic floor is non-existent?
Is it a 1&1/2-story or 2-story house?
What type of ventilation does it have?
I see that I wrote it wrong.KnockOnWood said:
It should be
And then I would have made the attic unventilated...
Sorry
If it is Fredrik's intention that the problem with underpressure in the living area should be solved, how do you propose to remediate it then Oceanis?
The thing is that even if you have an air pressure difference over the attic joist, it does not prevent moisture transport due to vapor pressure difference.
That's the tricky part with moisture transport - water can even move in the opposite direction simultaneously.
The thing is that even if you have an air pressure difference over the attic joist, it does not prevent moisture transport due to vapor pressure difference.
That's the tricky part with moisture transport - water can even move in the opposite direction simultaneously.
As it stands now, we will buy the house knowing that the roof needs to be redone, and with the cost of that included in the budget.
So the plan right now is to get quotes from several different contractors to address this, and possibly talk to an expert about what the best solution is for this particular attic.
Spontaneously (and without checking if this is the best solution) it might look like this:
1) Remove the existing tiles, felt, battens, sheathing, gutters, and downspouts.
2) Vacuum out all sawdust.
3) Install a vapor barrier in the ceiling joists.
4) Add insulation to the ceiling joists.
5) Install new sheathing, open up the eaves, install mold stoppers at the ridge, and improve the ventilation in the gables.
6) New battens, new tiles, new sheet metal work including gutters and pipes.
7) Install humidity-controlled fans like Pax in the bathrooms.
What I'm a bit worried about is that there probably isn't a vapor barrier in the walls of a house built in the '60s, and I've read that you shouldn't put a vapor barrier in the roof if it doesn't exist in the walls. But that's something an "expert" will have to comment on...
Does it sound reasonable?
So the plan right now is to get quotes from several different contractors to address this, and possibly talk to an expert about what the best solution is for this particular attic.
Spontaneously (and without checking if this is the best solution) it might look like this:
1) Remove the existing tiles, felt, battens, sheathing, gutters, and downspouts.
2) Vacuum out all sawdust.
3) Install a vapor barrier in the ceiling joists.
4) Add insulation to the ceiling joists.
5) Install new sheathing, open up the eaves, install mold stoppers at the ridge, and improve the ventilation in the gables.
6) New battens, new tiles, new sheet metal work including gutters and pipes.
7) Install humidity-controlled fans like Pax in the bathrooms.
What I'm a bit worried about is that there probably isn't a vapor barrier in the walls of a house built in the '60s, and I've read that you shouldn't put a vapor barrier in the roof if it doesn't exist in the walls. But that's something an "expert" will have to comment on...
Does it sound reasonable?
Remediation is not my specialty, but there are many who carry out remediation of black mold itself, and after-treatment with Boracol usually has the intended effect.Locke said:
With regard to the fact that there was the greatest impact around the hatch, it can probably be assumed that a negative pressure in the living area would change the relationship of air leakage up into the attic. One could add sealing or a better hatch.
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If the attic looks like that, then how does it look in the walls? If the humid air can be pushed up into the attic, it can just as well be pushed out into the walls, even though warm humid air normally rises upward.
As a buyer, I would probably try to remove some trim and panel boards in a few places to inspect this area as well. Or as a buyer is the wrong word. I would stay away from this house since it basically also requires replacing the rafters because these also have mold growth.
As a buyer, I would probably try to remove some trim and panel boards in a few places to inspect this area as well. Or as a buyer is the wrong word. I would stay away from this house since it basically also requires replacing the rafters because these also have mold growth.
What I meant, of course, is to create negative pressure in the living area to thus reduce the leakage of humid indoor air and then address the attic. Completely eliminating the leakage is probably not possible. But by ensuring that the ventilation provides constant air exchange (no intermittently running pax or other toys), the relative humidity in the indoor air decreases.
Lower RH in the indoor air results in less absolute humidity leaking to the attic.
If you only fix the attic without addressing the cause, you'll soon face growth again.
Fredrik
Lower RH in the indoor air results in less absolute humidity leaking to the attic.
If you only fix the attic without addressing the cause, you'll soon face growth again.
Fredrik
Yes, it sounds reasonable.samuel99 said:
Then one might consider a more advanced ventilation solution, which also saves some energy. If you are going to run pipes in the attic, it is very convenient to do it while the roof is off. It becomes much easier practically speaking.
Also, make sure to check that the walls are airtight (up against the attic). It would be unfortunate to put a vapor barrier in the ceiling and then have leaks through the walls. Normally, it shouldn’t happen, but there could be poor windproofing underneath. For example, only paneling without comprehensive boards/sheets/felt, and/or collapsed sawdust insulation. (There shouldn't be sawdust in the walls of 1960s houses, but you never know...)
Even more far-fetched is if the house has wood paneling and poorly insulated windows, allowing indoor air to leak around the windows, following the panel's air gap up to the eaves, and thus entering the attic. Or was there no eave ventilation? Well, then this idea wouldn’t hold.