"isolating" outside beam?

[kingnero]

Came accross a situation today to which I have no answer (but it's also not my field of expertise).
Anyone cares to comment for possible solutions?

Problems: wall rests on two beams (one for the inside wall, one for the outside wall).
Beams are partly outside the "warm envelope" of the building, and logically attract humidity as it's the coldest place in the building.
Currently humidity comes from a fresh-placed low-cement ratio concrete on which floortiles will be glued, yet the problem will continue to exist afterwards as well...

During construction of the addition:

detail:

Problem:
view from inside the old building towards the new addition:

from the addition, looking at the beams:

possible solutions?

 

[msquared48]

So one styeel beam is for the masonry veneer and one wood beam is for the wood frming?

Can you post a section through the wall?

I was going to suggest that you hire one of the three little pigs, but figured you wouldn't appreciate that suggestion, so I didn't say it.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[kingnero]

Please find a cross section attached.
House is build without any wood whatsoever or wherever (european style).

That means the steel is the coldest place inside the house (as it's coming from the "outside", as you can see from the first picture), hence the moisture is attracted to the beams (that are now covered by the plaster).

I couldn't really tell whether the three little pigs were a joke or a sarcastic way to tell I haven't shared enough information, so I am not going to comment on that. Gotta love the interwebs for ease of interpretation of written words...

 

[hokie66]

So just what is the question here? It looks like there has been a lot of leakage above the plastered areas, but it could have come from a variety of sources.

 

[kingnero]

No leakage, the humidity is attracted to that place, because it's the coldest place in the house.

Is there a way to "isolate" the beam so that the moisture will no longer accumulate there?

 

[hokie66]

Looks like leakage to me. But why is it the coldest place? Isn't the beam now interior to the building's envelope? If not, it should be.

 

[Parrapit]

I see you used 3 wooden beams with props to hold up the wall for knocking down the wall and placing in the steel beam underneath.

How well did it work, want to know if any settlement cracks or problems occur with this system.

Maybe a burst pipe or leaking pipe in wall or damage in water proofing, maybe around windows etc.

 

[kingnero]

Not leakage. it has gotten wet after finishing the floor, no rain at that time.

and it's half inside the building's envelope, half outside (see first picture: left half = inside, right half = outside). There's the problem...
In the third pic you can see the beams are uncovered (to outside conditions) above the window.

 

[kingnero]

@ Parrapit, no problems whatsoever, no cracks, only three holes in the wall that needed to be "filled in" again afterwards. common system here. when well done, no cracks nowhere.

Also, this is a complete renovation of the house, there are no pipes in that area. The naked beams feel really cold (as ambient temp is below zero °C, so I'm quite sure it's condensation. I just don't know how to solve it.

 

[hokie66]

Well, that is a heat transfer problem, so you as a mechanical engineer should be better able to tackle it than any of us structural engineers. But you can't leave the beams exposed and unflashed.

 

[XR250]

Can you post a pic of the exterior of the building now that it is finished?

 

[kingnero]

Will take some more this weekend, here's already something, showing the build:

 

[msquared48]

Sorry. The brick house and the big bad wolf just came to mind here. The one little pig did build the house correctly.

The section helps here.

Is there a way to vent the space and allow airflow to get rid of the moisture? I see the comment that the beams are now plastered over, so is this even possible now?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[BAretired]

The exterior portion of beam must be separated from the interior portion to prevent a cold bridge, not easily achieved in the finished building.

BA

 

[kingnero]

@M²: OK, I get it now.
venting is possible, but probably won't be sufficient to prevent further moisture inside the house.

@ BA: yes indeed, that's exactly my question from the very first post, how to "isolate" (or as you say, separate) the beams inside <> outside ...
When you say, not easily achieved, that means there must be a (hard) way?

 

[BAretired]

The hard way is to cut the steel beam and ensure that both beam ends are adequately supported on the wall, that two simple spans are adequate to carry the load and that the wall and foundation are capable of safely sustaining the new load.

BA

 

[kingnero]

The wall at the midspan of the beam is not a structural wall. Beam has been calc'ed for it's full span.
I was afraid you were going to say that, but I was hoping for a different solution

 

[BAretired]

Sorry, kingnero but I don't know any other way.

BA

 

[John2025]

Instead of venting, how about closed cell spray foam insulation along the entire length of the interior part of the beam(s).
It seems like a few inches of insulation and eliminating the flow of humid air against the cold steel should work. Redoing the plaster sounds easier than redoing the steel.

 

[MiketheEngineer]

Any chance of keeping them at the same temperature??