Hello forum,
and first of all, Merry Christmas to everyone.
I have a question regarding counter battens in my roof insulation work.
In my roof structure, I have installed 200mm (8 inches) insulation between the rafters and sealed it with a vapor barrier foil.
Now, I want to install the counter battens (24mm (1 inch) battens, with the spaces also insulated) to attach the drywall (gypsum board) to them.
What spacing between the battens is recommended?
A 600mm (24 inches) spacing seems too wide to me. Could the drywall sag or possibly warp over time?
I started the first batten at the knee wall and then spaced them every 600mm (24 inches) upwards. At the top, I attached another batten.
Or should I place a batten along the rafters?
and first of all, Merry Christmas to everyone.
I have a question regarding counter battens in my roof insulation work.
In my roof structure, I have installed 200mm (8 inches) insulation between the rafters and sealed it with a vapor barrier foil.
Now, I want to install the counter battens (24mm (1 inch) battens, with the spaces also insulated) to attach the drywall (gypsum board) to them.
What spacing between the battens is recommended?
A 600mm (24 inches) spacing seems too wide to me. Could the drywall sag or possibly warp over time?
I started the first batten at the knee wall and then spaced them every 600mm (24 inches) upwards. At the top, I attached another batten.
Or should I place a batten along the rafters?
@parcus,
So far, there has been no mention of a true vapor barrier.
The previous discussion has only referred to a vapor retarder.
If the Sd-value of the vapor retarder foil is correctly chosen, the roof assembly will function without condensation forming on the vapor retarder foil.
Regards,
KPS
So far, there has been no mention of a true vapor barrier.
The previous discussion has only referred to a vapor retarder.
If the Sd-value of the vapor retarder foil is correctly chosen, the roof assembly will function without condensation forming on the vapor retarder foil.
Regards,
KPS
The membrane shown in the picture is the vapor variable Vario KM Duplex with an Sd value between 0.3 and 5.0 meters (1.0 and 16.4 feet).
The manufacturer’s datasheet states:
"The variable Sd value of the Isover Vario KM Duplex can only be determined using a dynamic calculation program (e.g., according to the reference [10] in DIN 4108-3: 2001-07). Therefore, the Fraunhofer Institute Holzkirchen has specified that when using a static calculation method (DIN 4108-3: 2001-07 section 4.2 or A 6.2, e.g., the Glaser method), a fixed Sd value of 2.5 meters (8.2 feet) must be used for the Isover Vario KM Duplex."
The individual layers of the roof assembly must be designed so that the Sd value decreases from the interior to the exterior.
Since the construction of the roof above the rafters was not specified, I assume an underlay membrane with an Sd value of ≤ 0.02 meters (≤ 0.07 feet), battens, counter battens, and tiles or roof shingles.
In this case, no condensation is to be expected on the room side in front of the vapor barrier membrane.
In any case, it is recommended that both the thermal and hygrothermal calculations, as well as the airtightness testing, be carried out on site by qualified professionals.
The manufacturer’s datasheet states:
"The variable Sd value of the Isover Vario KM Duplex can only be determined using a dynamic calculation program (e.g., according to the reference [10] in DIN 4108-3: 2001-07). Therefore, the Fraunhofer Institute Holzkirchen has specified that when using a static calculation method (DIN 4108-3: 2001-07 section 4.2 or A 6.2, e.g., the Glaser method), a fixed Sd value of 2.5 meters (8.2 feet) must be used for the Isover Vario KM Duplex."
The individual layers of the roof assembly must be designed so that the Sd value decreases from the interior to the exterior.
Since the construction of the roof above the rafters was not specified, I assume an underlay membrane with an Sd value of ≤ 0.02 meters (≤ 0.07 feet), battens, counter battens, and tiles or roof shingles.
In this case, no condensation is to be expected on the room side in front of the vapor barrier membrane.
In any case, it is recommended that both the thermal and hygrothermal calculations, as well as the airtightness testing, be carried out on site by qualified professionals.
If it is a new build, vapor buildup can still occur.
Since drywall panels are not very dense, their sd-value is also low. Depending on the type and thickness of the paint coating, the sd-value ranges between 1 and possibly up to 10 m (3 to 33 ft).
However, I am only familiar with the above system as Vario with fleece.
Since drywall panels are not very dense, their sd-value is also low. Depending on the type and thickness of the paint coating, the sd-value ranges between 1 and possibly up to 10 m (3 to 33 ft).
However, I am only familiar with the above system as Vario with fleece.
Hello,
First of all, thank you for participating in my post.
Unfortunately, I only just found the time to read the articles.
A question was raised about why I fill the space between the drywall and the vapor barrier with insulation.
Well, I want to ensure that the entire structure does not sound "hollow."
I have shortened the batten spacing to 300mm (12 inches).
So, I added an additional batten in the middle of the already existing ones.
The drywall panels are then screwed vertically onto the battens.
I am using the single-person panels measuring 600 x 2250mm (24 x 89 inches). These fit perfectly in length between the collar beam connection and the knee wall.
I will have the blower door test conducted after completing the insulation work.
I have posted a construction diary for my house build online.
Have a nice evening.
First of all, thank you for participating in my post.
Unfortunately, I only just found the time to read the articles.
A question was raised about why I fill the space between the drywall and the vapor barrier with insulation.
Well, I want to ensure that the entire structure does not sound "hollow."
I have shortened the batten spacing to 300mm (12 inches).
So, I added an additional batten in the middle of the already existing ones.
The drywall panels are then screwed vertically onto the battens.
I am using the single-person panels measuring 600 x 2250mm (24 x 89 inches). These fit perfectly in length between the collar beam connection and the knee wall.
I will have the blower door test conducted after completing the insulation work.
I have posted a construction diary for my house build online.
Have a nice evening.
Hello,
for a new build, the risk would be too high for me.
Is it really specified that way in the layer structure?
With a simple gypsum board cladding, you get an sd-value of μ8 x 0.0125 m/μ = 0.1 m (0.33 ft).
As KPS correctly points out, the individual layers of the roof construction must be designed so that the sd-value (water vapor diffusion equivalent air layer thickness) decreases from the inside to the outside, following the absolute moisture content of the air.
In addition, the counter-battens should be at least 24 mm (1 inch) thick and follow the rafters, even if the DIN standard for interior construction does not require this as it does for exterior battens.
Best regards
for a new build, the risk would be too high for me.
Is it really specified that way in the layer structure?
With a simple gypsum board cladding, you get an sd-value of μ8 x 0.0125 m/μ = 0.1 m (0.33 ft).
As KPS correctly points out, the individual layers of the roof construction must be designed so that the sd-value (water vapor diffusion equivalent air layer thickness) decreases from the inside to the outside, following the absolute moisture content of the air.
In addition, the counter-battens should be at least 24 mm (1 inch) thick and follow the rafters, even if the DIN standard for interior construction does not require this as it does for exterior battens.
Best regards
Similar topics