Reinforce wooden beam

[-RB-]

Go to a blacksmith/mechanical workshop that can make a U-channel for you to place around the existing wooden beam. This way, you'll have material under the beam as well as on the sides. As long as the sides cannot buckle, it should be strong enough if you want to keep the wooden beam. It must be screwed firmly into the wooden beam. Possibly, a small flange at the top might be required. Otherwise, you can replace it with an I or HEA/HEB beam. Or you can proceed with your plan. It will be better than the existing beam regardless.

 

[smurfen72]

If you can secure the flat bar properly at the bottom of the wood it will turn out well, but that's the problem. A few screws are not likely to be enough, as they will be slightly loose in the holes and then it needs to sink quite a bit before the steel becomes useful. It would be different if you could weld the sheet metal, but that's difficult against wood

 

[Stefan1972]

Tested holding a 10 mm flat steel today; if you hold it flat, it bends and "wobbles" a bit, but if you stand it on edge, it doesn't move a mm!

I don't understand how a flat steel lying against the underside of the wooden beam would do much good; the weight will just bend it?!

Now I'm exaggerating the thought here, but I assume that's how "roli" thinks. Imagine your joists slightly arched upwards like a banana. Under this, you attach a flat steel anchored at the ends. The flat steel would then tether the ends so the wooden joist doesn't give way downwards. If you're going to do that, you'd have to make a banana out of the joist and then be able to fasten it to it 100% so it doesn't give even a millimeter. Perhaps a bit difficult.

 

[roli]

The screws must have "conical" heads and sit in countersunk holes so they can immediately take tensile forces when mounting a flat plate on the underside of the beam. Screws in loose holes are not a good option.

In this situation, the best solution is probably a U, H, or V-profile attached to the bottom of the wooden beam. Which one will be best depends on how much space is available and what can be acquired.

What I mentioned earlier was the most efficient reinforcement, which doesn't always have to be the best when the wooden beam is already installed.