Hello,
I’m new to the forum and have an urgent question!
We renovated a basement room.
In the old room:
- Earth floor with concrete blocks and impregnated boards on top (suitable for damp rooms)
- Small gap between wall and floor
- Wood paneling covering walls and ceiling
- Carpet flooring
The gap between the wooden boards and the wall is behind the wood paneling! (Moisture possibly coming from below can circulate between the wall/wood paneling and ceiling/wood paneling.)
New situation:
- Removed wood paneling
- Walls replastered
- Carpet removed, laminate installed
- New door installed
After about 2-3 months, mold appeared on the baseboards in two corners. 😱 Only the baseboards show mold, not the walls! Could this be because the gap needs to be kept open so moisture can escape? Should the baseboards be removed?
Is that enough, or do impregnated boards also allow moisture through and must the laminate be removed as well?
The relative humidity is about 60% with the baseboards installed and about 50% with the baseboards removed.
I’m asking for help and thank you in advance.
Best regards,
oh!-1
I’m new to the forum and have an urgent question!
We renovated a basement room.
In the old room:
- Earth floor with concrete blocks and impregnated boards on top (suitable for damp rooms)
- Small gap between wall and floor
- Wood paneling covering walls and ceiling
- Carpet flooring
The gap between the wooden boards and the wall is behind the wood paneling! (Moisture possibly coming from below can circulate between the wall/wood paneling and ceiling/wood paneling.)
New situation:
- Removed wood paneling
- Walls replastered
- Carpet removed, laminate installed
- New door installed
After about 2-3 months, mold appeared on the baseboards in two corners. 😱 Only the baseboards show mold, not the walls! Could this be because the gap needs to be kept open so moisture can escape? Should the baseboards be removed?
Is that enough, or do impregnated boards also allow moisture through and must the laminate be removed as well?
The relative humidity is about 60% with the baseboards installed and about 50% with the baseboards removed.
I’m asking for help and thank you in advance.
Best regards,
oh!-1
M
MODERATOR10 Aug 2010 18:01Hello Oh,
Converting a room that was originally planned as a basement space always comes with challenges related to moisture. This moisture can enter the interior from the ground and/or the exterior walls.
The previous construction took into account that moisture (vapor) could spread largely harmlessly. Wood is vapor-permeable, and gaps along with the substructure allowed for ventilation.
In the new construction, all of this was changed. Laminate flooring is not vapor-permeable, so moisture increasingly moves through the gap towards the wall, which is covered by the baseboards. That is why mold first appears around the baseboards, where the cooler, humid air condenses on the warmer (room temperature) baseboards. The underside of the laminate flooring will experience something similar.
Giving advice here is difficult; the basement room was simply not designed or built as living space. Most likely, there is no waterproofing on the exterior walls, no vapor barrier or sealing of the floor (obviously: earth floor).
You could install a raised floor (also elevated above the earth floor), cover this with a vapor barrier, and then lay a vapor-permeable floor covering (wood, carpet). The floor will remain dry permanently — however, the exterior walls will now be exposed to higher moisture levels, because the amount of moisture entering does not change, it will just be displaced to the vapor-permeable components.
Sealing from the inside will not help either.
Professional advice: seal and insulate the exterior walls from the outside, install an insulated concrete slab with a vapor barrier for the floor, and ensure good ventilation of the finished room.
I know this is a major effort, but otherwise you will not have a healthy living space.
One question: Were all components dry after the demolition — that is, before finishing with plaster and laminate?
Converting a room that was originally planned as a basement space always comes with challenges related to moisture. This moisture can enter the interior from the ground and/or the exterior walls.
The previous construction took into account that moisture (vapor) could spread largely harmlessly. Wood is vapor-permeable, and gaps along with the substructure allowed for ventilation.
In the new construction, all of this was changed. Laminate flooring is not vapor-permeable, so moisture increasingly moves through the gap towards the wall, which is covered by the baseboards. That is why mold first appears around the baseboards, where the cooler, humid air condenses on the warmer (room temperature) baseboards. The underside of the laminate flooring will experience something similar.
Giving advice here is difficult; the basement room was simply not designed or built as living space. Most likely, there is no waterproofing on the exterior walls, no vapor barrier or sealing of the floor (obviously: earth floor).
You could install a raised floor (also elevated above the earth floor), cover this with a vapor barrier, and then lay a vapor-permeable floor covering (wood, carpet). The floor will remain dry permanently — however, the exterior walls will now be exposed to higher moisture levels, because the amount of moisture entering does not change, it will just be displaced to the vapor-permeable components.
Sealing from the inside will not help either.
Professional advice: seal and insulate the exterior walls from the outside, install an insulated concrete slab with a vapor barrier for the floor, and ensure good ventilation of the finished room.
I know this is a major effort, but otherwise you will not have a healthy living space.
One question: Were all components dry after the demolition — that is, before finishing with plaster and laminate?
Yes! All parts were dry! Even the walls! Nothing is coming through from outside; it’s only from the ground!
I have now removed the baseboards all around and vacuumed out the remaining construction debris from the gaps. Now there is an open space between the wall, the floor, and the ground so moisture can pass through. I treated the mold, and the humidity is now exactly 50% and rises to 58-60% on rainy days. I will get a dehumidifier. I’ll give it a try like this. :o
Do impregnated wooden boards that are suitable for wet rooms allow moisture to pass through? 😕
I have now removed the baseboards all around and vacuumed out the remaining construction debris from the gaps. Now there is an open space between the wall, the floor, and the ground so moisture can pass through. I treated the mold, and the humidity is now exactly 50% and rises to 58-60% on rainy days. I will get a dehumidifier. I’ll give it a try like this. :o
Do impregnated wooden boards that are suitable for wet rooms allow moisture to pass through? 😕
M
MODERATOR11 Aug 2010 18:52Hello,
Wood preservatives generally do not make construction timber waterproof; rather, they protect it from damage caused by wood-destroying organisms such as fungi and insects. Moisture or water itself does not harm wood; it is the organisms that prefer damp wood.
Try leaving the gap between the floor and the wall open; however, the basement will not be suitable as a proper living space.
The measured humidity levels are physiologically acceptable. However, it is important to consider the relationship between room temperature and humidity: the warmer the air, the more moisture it can hold. For example, at 60% relative humidity, the room temperature should not fall below 12°C (54°F), otherwise there may be issues with dew formation/condensation.
Wood preservatives generally do not make construction timber waterproof; rather, they protect it from damage caused by wood-destroying organisms such as fungi and insects. Moisture or water itself does not harm wood; it is the organisms that prefer damp wood.
Try leaving the gap between the floor and the wall open; however, the basement will not be suitable as a proper living space.
The measured humidity levels are physiologically acceptable. However, it is important to consider the relationship between room temperature and humidity: the warmer the air, the more moisture it can hold. For example, at 60% relative humidity, the room temperature should not fall below 12°C (54°F), otherwise there may be issues with dew formation/condensation.
The current room temperature is always around 20°-23.5°C (68°-74.3°F) with humidity at 50-60%. Is it sufficient if the gap at its smallest point is about 2-3mm (0.08-0.12 inches) and at the largest point 2-3cm (0.8-1.2 inches) wide? I will definitely place a dehumidifier inside.
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