Wood beams infested with woodworm - Is there anything that can be done?

Hello everyone,
I am the owner of a half-timbered house built around 1800. The half-timbering was already completely covered and, except for the rear facade, fully insulated when I received the house as a gift. Now I want to also clad the back wall with a ventilated insulation system. Currently, the facade is covered with tar paper panels with a brick look. When I looked at the beams behind the half-timbered facade, I noticed that (so far) one beam was apparently infested by woodworm. On an area of 2x2 cm the screwdriver went through like butter. All around, the beam is completely solid and can only be adjusted with force using a screwdriver. Is this critical and does or should the beam be replaced? This would of course be an enormous effort.

Have a professional on site take a look. There is nothing more to say about it. You cannot assess the condition of a beam by looking into a crystal ball, nor can you evaluate it. Even if you had posted a required photo here, a remote diagnosis would be pointless. Nowadays, there are ways to replace even just parts of a beam, but a professional should examine any fungus, insects, or mold.

Beams can become soft for a variety of reasons, animals are only part of the causes and the woodworm is not the only one nibbling there. I don’t want to list them.

Woodworms are generally interested in softwood under 50 years old. After that the protein has broken down, even the most frugal worm could eat itself hungry. You can recognize an active worm by the wood dust and if things get nasty, you can even hear it “sawing” a little bit during quiet phases. But let’s not assume that now :)

You need a professional! I would kindly ask the lower monument protection authority for advice and if possible for an inspection. Structural integrity is no joke, you also need a reliable statement here. Half-timbered houses are like surprise eggs: you can shake them but you only really see what’s inside when you open them. Extensions are possible.

Beams can be saved and in historic buildings you can often see patched pieces in long exposed roof structures. If it’s really just a small piece (2m is small, the procedure itself is expensive), you can stabilize it without removing it using an injection method. This essentially means filling the beam with synthetic resin using suspended injection syringes, but it’s already a bit cold outside for that. It will still look like a beam, but actually it’s the synthetic resin that carries the load.

I’m keeping my fingers crossed for you!
Gabriele