Wooden lintel partially rotten

[aandk]

When stripping out to re-board walls and ceiling we have discovered one end of a wooden lintel has completely disintegrated as a result of a water leak. The leak was repaired around ten years ago from what we can tell but obviously the damage wasn’t! Oddly we found newspapers from 2014 stuffed in by the lintel that are bone dry, so that’s something at least.

We’d like advice on how big a job/fix this needs to be - can it be “patched” in any way? Can we use treated timber rather than steel?

Kind of annoyed we even found it as no sign anything has really gone wrong. Although we suspect the studs in the lathe and plaster wall are taking load that they shouldn’t be, so if we’d knocked them out (no plans to) it could have been more of a disaster. Photos show damaged area and other side of same wall.

The room is on the back of the house and has a pitched roof and comes off the turn in the stairs - so is lower than the main bedrooms in the main section of the house.

 

[Cubist]

Hi There and Welcome,
Sadly that's no small job insofar that the rotten beam/lintel (I'm trying not to be a pedant over terminology) is supporting what appears to be a brick infill that is possibly/probably carrying the roof. Which in all likelihood was the root cause of the water leak that produced the rot. Whether, and how much of, the beam can be saved depends on the extent of the rot and that will determine the potential materials cost. Suitable timber per foot length can be expensive compared to steel but has the flexibility of being able to specify the key dimensions such as height and width where steels are typically manufactured to common standards.

Final costs though will be determined by the labour and equipment rental which in turn may be adversely affected by the nature of the site. Unless you are a very determined and competent DIYer you would be wise to get a few quotes from reputable local outfits who can provide testimonials from past customers.

However, should you decide to take the job on yourself I and others here would be happy to offer what advice we can.

Cheers for now,
Cubist

 

[Lacan07]

I don't see how you can salvage that beam, surely its load bearing capacities are redundant. You can cut back the rotten wood and replace but how do you bolt the new to whats left in a way that provides any kind of integrity? Perhaps on this occasion its worth consulting a structural engineer. Some kind of vertical post, or series of posts, in that corner might suffice.

 

[Stevers]

It looks like a timber stud frame supporting a 9" English bond brick wall. I'm guessing that the 9" wall is exposed externally. I doubt whether it could be classed as a beam as such as it looks far too slender to carry that load without the studs under. It's a most unorthodox form of construction, and it would be interesting to know what's underneath that stud frame wall.

 

[malcolm]

It looks like a tie beam helping to resist roof spread and someone does appear to have built a brick wall on top. The repair to the rafter doesn't look great. What's the wall plate (the timber on the top of the wall where the rafter and tie beam connect like?

Breaking the job down a bit a wall plate repair is easy. Cut the rotten bit out and scarf a new bit in. It needs to be scarfed as the rafters are pushing it outwards and the tie beams are pulling it inwards A bad joint might make things pull squint.

That rafter repair is no good. In the ones I found in a roof the new sistered repair section want right up to the purlin. I would certainly have at least a couple of feet overlap on good wood.

The tie beam looks more problematic as the bricks above will likely fall down if you remove it completely. Best to remove only the rotten part and scarf in new wood to minimise disruption to the bricks. It is a tension member so it's well worth adding a steel strap to take the tension in the joint. That could just be a couple of feet steel strip screwed to the old and new bits.

Here's one I prepared earlier. The wall plate join and rafter sistering were done by someone else. The steel end on the tie beam is mine and it's excessive as I had roof spread and only a tiny bit of the tie beams were resting on the wall plate. I couldn't figure out why the roof hadn't already collapsed.

It can be a DIY job. If you need professionals involved it's worth figuring out the fix yourself first to avoid it becoming a very expensive job.