ᐅ Load-bearing wooden beam (installed in 1908) with a longitudinal crack and creaking under load – is this normal or a cause for concern?
Created on: 18 Mar 2026 18:14
L
LyssHello everyone 🙂
We have a load-bearing wooden beam in the attic with a large longitudinal crack (see photos). The crack runs almost the entire length along the grain. The house was built around 1908, so unfortunately we don’t know if the crack has been like this for a long time or if it has changed over time.
The beam creaks, for example when someone is jumping on the trampoline nearby. In the adjacent room, there is also a washing machine that causes vibrations when spinning. According to the previous owners, the beam had woodworms over 30 years ago, and you can still see some small holes.
The crack is up to about 1 cm (0.4 inches) wide in two beams and seems to extend almost to the middle of the beam in some places.
My questions:
Is a crack like this normal or critical for an old beam? And if it is still structurally sound – is it okay to continue using it under normal loads (e.g., jumping on the trampoline nearby or doing exercises with a resistance band attached to it), or should such loads be avoided?
I was also told that sudden load peaks might be problematic. If securing or repairing such an issue is necessary (for example, due to the washing machine vibrations): very roughly, what costs could be expected, or should one first consult a structural engineer rather than a carpenter?
The largest crack in the main beam is 1.4 cm (0.55 inches) wide, and it seems as if the crack “opens” at the ends – the material visible below is just some insulation foam that can be seen in the picture.
Thanks in advance! 🙂
We have a load-bearing wooden beam in the attic with a large longitudinal crack (see photos). The crack runs almost the entire length along the grain. The house was built around 1908, so unfortunately we don’t know if the crack has been like this for a long time or if it has changed over time.
The beam creaks, for example when someone is jumping on the trampoline nearby. In the adjacent room, there is also a washing machine that causes vibrations when spinning. According to the previous owners, the beam had woodworms over 30 years ago, and you can still see some small holes.
The crack is up to about 1 cm (0.4 inches) wide in two beams and seems to extend almost to the middle of the beam in some places.
My questions:
Is a crack like this normal or critical for an old beam? And if it is still structurally sound – is it okay to continue using it under normal loads (e.g., jumping on the trampoline nearby or doing exercises with a resistance band attached to it), or should such loads be avoided?
I was also told that sudden load peaks might be problematic. If securing or repairing such an issue is necessary (for example, due to the washing machine vibrations): very roughly, what costs could be expected, or should one first consult a structural engineer rather than a carpenter?
The largest crack in the main beam is 1.4 cm (0.55 inches) wide, and it seems as if the crack “opens” at the ends – the material visible below is just some insulation foam that can be seen in the picture.
Thanks in advance! 🙂
Similar topics