ᐅ Installing click-lock vinyl flooring despite possibly excessive residual moisture
Created on: 21 Nov 2023 10:49
J
jrth2151Just as a preliminary note:
Yes, I wouldn’t recommend this to anyone myself, and yes, I know that a CM measurement has to be done, as it is the only truly reliable method to measure residual moisture.
And yes, I know we like to educate each other here in the forum, but please put that aside for a moment and follow my explanation.
Our calcium aluminate screed (alpha-hemihydrate) was installed on 26.07.23. The windows remained closed for three days afterwards, and the house was not entered. After that, we started ventilating several times daily with burst ventilation. We always monitored the hx diagram to achieve the lowest possible relative indoor humidity matching the outdoor conditions.
After three weeks, the functional/maturity heating began. The flow temperature was gradually increased and then maintained at 50°C (122°F) for a total of 14 days. Afterwards, the temperature was slowly reduced to 21°C (70°F).
Then I measured residual moisture with an electric moisture meter (yes, inaccurate) and got a reading of less than 0.2%. So at least the indicators look good so far.
We then had no heating for about four weeks but continued ventilating optimally according to the hx diagram. Since last week, the heating has been running again at 21°C (70°F).
That’s the background information.
The issue:
We have to move in before Christmas because we have already terminated our rental contract and the loan repayment has started. That means we can hardly afford to wait any longer anyway. It would practically be impossible.
At the end of next week, we will be installing floating click vinyl flooring—Wineo 600 rigid. Now let’s assume I don’t do a CM measurement. What is the worst-case scenario? Does anyone here have experience with this? We would leave off the baseboards until a few weeks later and only cover the essential rooms such as the bedrooms and open-plan kitchen/living area.
And again, I wouldn’t personally recommend this to anyone, but unfortunately, we really have no other real choice now…
Yes, I wouldn’t recommend this to anyone myself, and yes, I know that a CM measurement has to be done, as it is the only truly reliable method to measure residual moisture.
And yes, I know we like to educate each other here in the forum, but please put that aside for a moment and follow my explanation.
Our calcium aluminate screed (alpha-hemihydrate) was installed on 26.07.23. The windows remained closed for three days afterwards, and the house was not entered. After that, we started ventilating several times daily with burst ventilation. We always monitored the hx diagram to achieve the lowest possible relative indoor humidity matching the outdoor conditions.
After three weeks, the functional/maturity heating began. The flow temperature was gradually increased and then maintained at 50°C (122°F) for a total of 14 days. Afterwards, the temperature was slowly reduced to 21°C (70°F).
Then I measured residual moisture with an electric moisture meter (yes, inaccurate) and got a reading of less than 0.2%. So at least the indicators look good so far.
We then had no heating for about four weeks but continued ventilating optimally according to the hx diagram. Since last week, the heating has been running again at 21°C (70°F).
That’s the background information.
The issue:
We have to move in before Christmas because we have already terminated our rental contract and the loan repayment has started. That means we can hardly afford to wait any longer anyway. It would practically be impossible.
At the end of next week, we will be installing floating click vinyl flooring—Wineo 600 rigid. Now let’s assume I don’t do a CM measurement. What is the worst-case scenario? Does anyone here have experience with this? We would leave off the baseboards until a few weeks later and only cover the essential rooms such as the bedrooms and open-plan kitchen/living area.
And again, I wouldn’t personally recommend this to anyone, but unfortunately, we really have no other real choice now…
The manufacturer, Windmöller GmbH, specifies the following in their installation guide for "Wineo 600 rigid":
"Contrary to DIN 18560, we recommend a maximum residual moisture of ≤ 0.3% CM for calcium sulfate screed (CA screed)."
DIN 18560 Part 2 specifies a maximum residual moisture of ≤ 0.5% CM for calcium sulfate screed (CAF).
This means that the substrate board of the design flooring reacts to (rising moisture from the rear).
Anyone who does not perform a CM measurement cannot confirm whether the substrate is properly dry for installation.
This, in turn, means that anyone who installs the flooring anyway assumes full remaining risk.
But the initial question was what could happen if the substrate is still too moist.
In that case, the substrate board would swell, leading to warping and changes in length.
The extent of these undesirable effects cannot be specified.
In extreme cases, the new surface layer is so warped that trip hazards form, locking joints release from their connection, and sections lift by several millimeters (millimeters).
This represents an irreversible total loss, requiring a complete renovation, which may also involve the removal of kitchen cabinets.
The "foil test" mentioned by another forum participant provides a fairly reliable and meaningful prognosis.
You will need:
- two hygrometers
- a thermometer
- a thicker polyethylene (PE) foil, approx. 40cm x 40cm (16 inches x 16 inches)
- adhesive tape
- a pen and a sheet of paper
The underfloor heating must be running, the room well ventilated, then place the foil on the screed.
Set the first hygrometer in the middle under the foil, then seal the foil edges tightly to the screed surface with the adhesive tape.
After approximately 24 hours, use the second hygrometer and the thermometer to record the indoor climate conditions in the room. Then place the second hygrometer and the thermometer on the outer windowsill, close the window, and after about 30 minutes record the outdoor values.
Now read the relative humidity under the foil. The temperature is the same as first measured in the room.
Evaluation option (1):
If the humidity under the foil is <65% and equal to or less than the humidity measured in the room, then sufficient drying of the screed can be assumed.
Evaluation option (2):
This is somewhat more complex but more accurate, requiring a building physics reference table to compare the absolute moisture content (in g/m³) both outdoors and under the foil.
Option (1) should be sufficient for laypersons.
However, as stated initially, the CM residual moisture measurement (unfortunately) remains the only recognized method.
The foil test is based on the KLR method and is widely debated within the trade.
---------------------------------
Best of luck with your further process:
KlaRa
"Contrary to DIN 18560, we recommend a maximum residual moisture of ≤ 0.3% CM for calcium sulfate screed (CA screed)."
DIN 18560 Part 2 specifies a maximum residual moisture of ≤ 0.5% CM for calcium sulfate screed (CAF).
This means that the substrate board of the design flooring reacts to (rising moisture from the rear).
Anyone who does not perform a CM measurement cannot confirm whether the substrate is properly dry for installation.
This, in turn, means that anyone who installs the flooring anyway assumes full remaining risk.
But the initial question was what could happen if the substrate is still too moist.
In that case, the substrate board would swell, leading to warping and changes in length.
The extent of these undesirable effects cannot be specified.
In extreme cases, the new surface layer is so warped that trip hazards form, locking joints release from their connection, and sections lift by several millimeters (millimeters).
This represents an irreversible total loss, requiring a complete renovation, which may also involve the removal of kitchen cabinets.
The "foil test" mentioned by another forum participant provides a fairly reliable and meaningful prognosis.
You will need:
- two hygrometers
- a thermometer
- a thicker polyethylene (PE) foil, approx. 40cm x 40cm (16 inches x 16 inches)
- adhesive tape
- a pen and a sheet of paper
The underfloor heating must be running, the room well ventilated, then place the foil on the screed.
Set the first hygrometer in the middle under the foil, then seal the foil edges tightly to the screed surface with the adhesive tape.
After approximately 24 hours, use the second hygrometer and the thermometer to record the indoor climate conditions in the room. Then place the second hygrometer and the thermometer on the outer windowsill, close the window, and after about 30 minutes record the outdoor values.
Now read the relative humidity under the foil. The temperature is the same as first measured in the room.
Evaluation option (1):
If the humidity under the foil is <65% and equal to or less than the humidity measured in the room, then sufficient drying of the screed can be assumed.
Evaluation option (2):
This is somewhat more complex but more accurate, requiring a building physics reference table to compare the absolute moisture content (in g/m³) both outdoors and under the foil.
Option (1) should be sufficient for laypersons.
However, as stated initially, the CM residual moisture measurement (unfortunately) remains the only recognized method.
The foil test is based on the KLR method and is widely debated within the trade.
---------------------------------
Best of luck with your further process:
KlaRa
M
motorradsilke21 Nov 2023 20:49Why don’t you just have a measurement done? That way, you can be sure and have certainty for yourself as well.
motorradsilke schrieb:
Why don’t you just have a measurement done? That way you can be sure and have peace of mind.Maybe we should first ask the original poster if there are any marked measurement points in the screed? This is quite important to avoid hitting the heating pipes when taking samples with a hammer and chisel...
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