Yes, but the problem mentioned is not from moisture within the house, which as you state, "the cold A/C coils are going to suck the moisture out of the air". The problem as stated in the opening post is underneath the linoleum or vinyl flooring, which is "bubbling up".
First off, cold air doesn't attract moisture... it is the warm moist air that that condenses because of the stark temperature differential as it contacts the colder surface or barrier which separates the inside and outside temperature difference. The purpose of insulation is to dampen that temperature difference and minimize temperature transfer. The idea of a moisture barrier is just that, to prevent humidity from condensing or transferring beyond the barrier.
When I wrote, "When a house is air-conditioned that moisture will condense on colder surfaces.", I definitely overstated the conditions. I really don't think that the interior of the house would be so cold as to actually cause condensation to form in any visible manner. If so, you'd see the windows fog up on the outside. But, unlike windows, the floor covering is probably the coldest spot in an air conditioned room, and it is possible that moisture could collect underneath, since the floor covering is acting as the first moisture barrier between the warm outside humid air and the dry cooled air inside.
However, even it there were no air conditioning or temperature differential between inside and out, moisture will condense on the first non-porous, moisture resistant surface it encounters. Examples of that is morning dew, condensate on your tent in the early morning, and underneath anything layed close to ground, even in good weather. Lay a piece of plywood or a tarp on the ground and chances are in a very short time moisture will collect on the bottom. For example, I have and old garage, with an unsealed concrete floor. I don't drive my 95' Miata in any kind of wet weather and certainly not in the winter... so in 20 years, that car has only seen rain a few times and never snow. But I noticed the first year I put it in this garage, the underside was a wet mess that winter. It's an unheated garage so there's no temperature differential at all. But moisture penetrating the garage floor was collecting on the first non-porous barrier it came to... my Miata. Easy cure, I now park the car on a double layer of moisture-proof tarp and the car stays dry.
Years ago when we were looking for a house, I encountered a very nice looking home, that was destroyed on the inside. Apparently the house had just been shut up. No windows left open. Moisture penetrating the basement concrete was horrible. When the realtor opened the front door, we were practically knocked down my the humidity and stench of mold. It had been a beautiful home, but the floors were all cupped and there was mold on the inside of many of the windows. We went down into the basement thinking that perhaps a pipe had burst. But the plumbing was fine. The basement had a pretty good concrete floor, but the walls were cinderblocks. No cracks, but they too were almost green with mold and there was condensate dripping off the ceiling joists and collected up on the subfloor.
I have no idea how long that house had been sealed up. Even normal comings and goings would have prevented such damage I think. Venting is very important.
CWS
First off, cold air doesn't attract moisture... it is the warm moist air that that condenses because of the stark temperature differential as it contacts the colder surface or barrier which separates the inside and outside temperature difference. The purpose of insulation is to dampen that temperature difference and minimize temperature transfer. The idea of a moisture barrier is just that, to prevent humidity from condensing or transferring beyond the barrier.
When I wrote, "When a house is air-conditioned that moisture will condense on colder surfaces.", I definitely overstated the conditions. I really don't think that the interior of the house would be so cold as to actually cause condensation to form in any visible manner. If so, you'd see the windows fog up on the outside. But, unlike windows, the floor covering is probably the coldest spot in an air conditioned room, and it is possible that moisture could collect underneath, since the floor covering is acting as the first moisture barrier between the warm outside humid air and the dry cooled air inside.
However, even it there were no air conditioning or temperature differential between inside and out, moisture will condense on the first non-porous, moisture resistant surface it encounters. Examples of that is morning dew, condensate on your tent in the early morning, and underneath anything layed close to ground, even in good weather. Lay a piece of plywood or a tarp on the ground and chances are in a very short time moisture will collect on the bottom. For example, I have and old garage, with an unsealed concrete floor. I don't drive my 95' Miata in any kind of wet weather and certainly not in the winter... so in 20 years, that car has only seen rain a few times and never snow. But I noticed the first year I put it in this garage, the underside was a wet mess that winter. It's an unheated garage so there's no temperature differential at all. But moisture penetrating the garage floor was collecting on the first non-porous barrier it came to... my Miata. Easy cure, I now park the car on a double layer of moisture-proof tarp and the car stays dry.
Years ago when we were looking for a house, I encountered a very nice looking home, that was destroyed on the inside. Apparently the house had just been shut up. No windows left open. Moisture penetrating the basement concrete was horrible. When the realtor opened the front door, we were practically knocked down my the humidity and stench of mold. It had been a beautiful home, but the floors were all cupped and there was mold on the inside of many of the windows. We went down into the basement thinking that perhaps a pipe had burst. But the plumbing was fine. The basement had a pretty good concrete floor, but the walls were cinderblocks. No cracks, but they too were almost green with mold and there was condensate dripping off the ceiling joists and collected up on the subfloor.
I have no idea how long that house had been sealed up. Even normal comings and goings would have prevented such damage I think. Venting is very important.
CWS
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