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The 2-Year Apartment Rule

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181–190 of 194 posts

Re: The 2-Year Apartment Rule

#182
post #161

Earlier quoted context omitted.

Trailer park in California. It's a prefab kit built accessory room. The main part of the trailer is normal, just this accessory room is built out of aluminum panels (about 3' x 9' per panel) and then plenty of single pane windows.

Mold growth is a moisture problem which can either be because of condensation or because of leaks. I agree with the contractors, properly framing out and insulating the interior would probably help a lot with condensation on the inside of the aluminum, as would double pane windows. Ventilation is also important for stopping mold growth.

Or it could just hide the mold behind the insulation if done poorly. In cold weather, when cavity insulation, the inner surface of the metal will be cold. If warm, humid interior air that can sneak behind the insulation and get to that surface, it will condense. And metal is impermeable to moisture, so it can’t dry to the exterior.

One technique to mitigate this that does not require extraordinary care on the part of the installer is “flash and batt”: apply a thin layer of spray foam to the exterior wall and then fill the cavity with fiberglass, mineral wool or some other fluffy insulation. The spray foam adheres to the wall and leaves no space for humid air to reach, and the inner surface of the spray foam will stay warm enough to avoid condensation.

Re: The 2-Year Apartment Rule

#183
post #90

Earlier quoted context omitted.

I think this depends on the construction of the rest of the house. A typical stack built house in the US will have extensive insulation in the exterior walls, but it's paired with a number of different layers intended to expel moisture. As a retrofit without those things I guess I can see it being problematic.

Maybe everyone here can help me. I bought a house with an accessory addon already built, but it's walls and roof are very cheap aluminum. It's a constant source of mold. I'm at the point where I want to demolish it and rebuild properly. Some contractors I've spoken with instead encourage me to just frame out inside the existing aluminum box and get double pane windows instead. I don't think that will solve the proble…

The walls are getting below dew point when they cool and/or the humidity is too high for extended periods. And the walls have dust or other surface accumulations conducive to mold. Insulating the exterior and keeping the interior humidity low will help. Thoroughly clean and dry the interior walls, removing all mold and all other surface accumulations. Keep the interior above dew point.

Re: The 2-Year Apartment Rule

#184

Earlier quoted context omitted.

Who has cavity wall insulation removed? The effect on your heating bill is going to be much worse than a small amount of mould Some of these houses have been transformed into being unfit for human habitation due to the damp and mould. In some cases, the botched insulation has resulted in an increase in heating costs (along with the damp and mold). Some have suffered structural damage due to the botched insulation, co…

How did they botch it? Definitely a [citation needed] here...

Here’s an extremely snarky take, from an author who is very much an expert in the field:

https://buildingscience.com/documents/building-science-insig...

Re: The 2-Year Apartment Rule

#185
post #176

Earlier quoted context omitted.

> The recurring leak might not be the author's fault, but the... roaches in the kitchen definitely are "Definitely"? A unit can look clean after treatment while still being mid-cycle. Rent it during that window and the roaches come back through no fault of the tenant. It wouldn't even be that crazy to postulate the life-cycle of a roach could track the 2-Year Apartment Rule (minus any residual effects of the extermin…

> "Definitely"? A unit can look clean after treatment while still being mid-cycle. Rent it during that window and the roaches come back through no fault of the tenant. "A unit" can, sure. But, "every apartment I've ever lived in"... come on! From TFA: > I've noticed this myself with every apartment I've ever lived in. Things start off fine, but then mold starts growing in the bathroom, and a recurring leak springs up…

I'd extend some good faith to someone reporting a potential community health problem. And roaches in a kitchen isn't a smoking gun. Roach bait is food. Poisoned food, but food. You put it in the kitchen on purpose. Next to the food. That is how it works.

Re: The 2-Year Apartment Rule

#186
post #48

Earlier quoted context omitted.

> most mould is caused by buildings. An honourable mention to fitting Cavity Wall Insulation , heavily sold and encouraged by UK government energy saving schemes thorough the 1990's and 2000's. Except by stuffing the wall cavity, you provide a nice moisture bridge to outside whilst simultaneously stopping air circulating in the cavity and whipping away moisture; thus an explosion of mould. The policy was a disaster,…

Who has cavity wall insulation removed? The effect on your heating bill is going to be much worse than a small amount of mould, and I'm unconvinced that it makes it worse anyway - one of the main causes of mould in my experience is poor insulation! It makes the walls cold, which means you get condensation on them, and if you have poor ventilation in the rooms then you get mould. If you have this problem, then the onl…

> The effect on your heating bill is going to be much worse than a small amount of mould

A small amount of mould?

Oh you sweet summer child! You really need to see the damage it can do.

Re: The 2-Year Apartment Rule

#187
post #61
post #38

Earlier quoted context omitted.

Yes, but no. We have historic, sometimes even mediaeval buildings. They weren't built with the current energy efficiency in mind. Leaving the bathroom door open after showering. Not putting furniture flus against the wall are simple measures you could take that don't need structural adaptations. I know there are plentiful of technical options but some common sense goes a long way.

It infuriates me to no end that we are expected to put up with building design and technology from 1900 as a consequence of the obsession with "property values must go up" (notwithstanding the property ) and a healthy helping of "regulations are only ever added to, everything old is forever grandfathered". Like, central ventilation is not magical unobtainable technology. Simple heat recovery even vastly improves heat…

My home from the 1700s would have been demolished and rebuilt from scratch dozens of times if this was the reality we live in.

Not everyone lives in a disposable McMansion in a gated community.

Re: The 2-Year Apartment Rule

#188

Earlier quoted context omitted.

They remove a small amount of moisture, yes. It's nothing compared to what a dehumidifier removes though, even if they're in dry mode.

A condensate dehumidifier is just an air conditioner where the condenser is inside the same space as the evaporator. It uses vapor compression refrigeration. Granted, the condenser and evaporator both condensing moisture inside of the space does remove more moisture so you’re correct about it being more effective, but an A/C unit does a pretty good job where I live, and cooler air holds less moisture. I never deal wi…

It's probably relative to how much humidity there is where you are. I'm in a very humid area, and I have humidity sensors. Leaving an AC unit on dry mode in a small room does basically nothing - at most it will shift humidity by a few percentage points. Meanwhile if I use the actual dehumidifier I can drop from 85-90% down to 65%. If I turn the machine off for a few hours (or move it to another room) it'll be back up in no time.

Re: The 2-Year Apartment Rule

#189

The best thing I've found after dealing with mold is a simple 3% hydrogen peroxide solution that is sold in any drugstore. Put it in a spray bottle and soak the area deeply enough and it should kill it down to the roots. And a plus is that when it breaks down the only fumes it gives off is pure oxygen, unlike other cleaners like bleach. It did such a good job that I use peroxide as a general purpose cleaner now. I wi…

Hydrogen peroxide is also great for disinfecting just the edges of a reflecting pool.

Re: The 2-Year Apartment Rule

#190
post #182
post #161

Earlier quoted context omitted.

Mold growth is a moisture problem which can either be because of condensation or because of leaks. I agree with the contractors, properly framing out and insulating the interior would probably help a lot with condensation on the inside of the aluminum, as would double pane windows. Ventilation is also important for stopping mold growth.

Or it could just hide the mold behind the insulation if done poorly. In cold weather, when cavity insulation, the inner surface of the metal will be cold. If warm, humid interior air that can sneak behind the insulation and get to that surface, it will condense. And metal is impermeable to moisture, so it can’t dry to the exterior. One technique to mitigate this that does not require extraordinary care on the part of…

I very much appreciate all of the replies, everyone is sharing their knowledge and it helps me feel more informed on what to do.
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