Repair 4x12 beam

[Peddler9]

Is it structurally sound to add 2x12x?'s to each side of a 4x12 beam to reinforce the beam due to water damage pictured? I have resolved the slope issue which caused the water damage. Replacing these beams is something I would rather like to avoid.

Clearly I would need to remove the dry rot on the beams. It appears the previous owner removed some dry rot, notched the beam and replaced with some new wood. However they never fixed the slope that caused the water damage.

 

[phamENG]

I would suggest having a local engineer evaluate it and design a repair. Sometimes that repair is slapping some new wood on the sides, sometimes it's not. Need 'boots on the ground' to know for sure.

 

[SWComposites]

In looking at that photo, you need to replace a lot more that just the rotten beam.

And if the beam in question is the lower beam in the photo, then slapping on doublers on the side is likely not appropriate.

Get a local engineer out there to assess it in person.

 

[lexpatrie]

You'd want it sterile and dry before you sister anything to the existing. First off the connection to the existing is probably weakened a fair bit by the rot, even if dry, and second, there's really no established protocol for the capacity of nailing into "that," in the engineering sense. One might reduce the specific gravity and check the nailing that way but the specific gravity used isn't based on anything besides "I'll reduce it 20%", versus research.

The issue with sistering to something that's got rot, is it can spread to the new element and deteriorate it faster than you'd normally expect, especially if it's wet, and then you enclose it, let alone the chances for fungal development which could lead to more strength loss from wood fiber damage.