Hello
I have a question about who is responsible for the costs. I started building my house in September 2016 and successfully completed it in October 2017. The house is single-story. My problem is that I have very large cracks between the walls and ceiling on the upper floor. They are almost 2 cm (0.8 inches) wide. The upper floor does not have a concrete ceiling; it only has drywall. Last summer, I installed OSB boards on the attic floor and screwed them onto the roof beams. According to the construction company, I should only leave space for ventilation at the sides and the gable. I followed these instructions. However, the site manager now tells me that the cracks were caused because the OSB boards expanded and, since they are screwed in, pushed the entire roof structure upward. Fixing this would cost me about 1000 euros.
About a week ago, I removed all the screws from the boards on the attic floor. The site manager said the roof structure would lower again, but so far nothing has happened. The cracks are at the top of every room. I screwed the OSB boards onto the attic floor in July of last year, and the cracks appeared in November.
Is it really possible that the OSB boards could push the entire roof structure upward by almost 2 cm (0.8 inches)? I would be very grateful for any advice, as I don’t really understand this issue.
P.S. If pictures are needed, I can provide them without any problem.
Thanks in advance.
Best regards
I have a question about who is responsible for the costs. I started building my house in September 2016 and successfully completed it in October 2017. The house is single-story. My problem is that I have very large cracks between the walls and ceiling on the upper floor. They are almost 2 cm (0.8 inches) wide. The upper floor does not have a concrete ceiling; it only has drywall. Last summer, I installed OSB boards on the attic floor and screwed them onto the roof beams. According to the construction company, I should only leave space for ventilation at the sides and the gable. I followed these instructions. However, the site manager now tells me that the cracks were caused because the OSB boards expanded and, since they are screwed in, pushed the entire roof structure upward. Fixing this would cost me about 1000 euros.
About a week ago, I removed all the screws from the boards on the attic floor. The site manager said the roof structure would lower again, but so far nothing has happened. The cracks are at the top of every room. I screwed the OSB boards onto the attic floor in July of last year, and the cracks appeared in November.
Is it really possible that the OSB boards could push the entire roof structure upward by almost 2 cm (0.8 inches)? I would be very grateful for any advice, as I don’t really understand this issue.
P.S. If pictures are needed, I can provide them without any problem.
Thanks in advance.
Best regards
Wood mainly responds to moisture rather than temperature. Temperature-related expansion can usually be disregarded. If the panels were causing the issue, they would have to somehow overcome the screws, since these are fixed to the substrate. It’s not only the last section of the panel before the first screw that expands. Even an OSB panel affected by moisture movement (which is unlikely with typical OSB 3) would more likely warp between the screws and move away from the structure locally rather than lifting off completely.
AOLNCM schrieb:
The roofers have to use technically dried battens (for wood protection reasons). The drywall installers do not. Due to the low humidity, the counter battens installed by the drywall installers shrink mainly in winter. This causes the cracks.That is not incorrect, but it can never cause the roof structure to lift. Consider how much weight is behind it. Neither an OSB board nor the screws used can cause that. Furthermore, the expansions caused by drying/swelling are not in the range of 2cm (around 0.8 inches), unless wood from sea storage was used.
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