Comment on Plant growing out of (or nearby) a wood support beam, which has become soft and wet

livligkinkajou@slrpnk.net ⁨1⁩ ⁨month⁩ ago

• diyrebel@lemmy.dbzer0.com ⁨1⁩ ⁨month⁩ ago

  Are you sure all that humidity is coming from the outside? It looks like a really weird spot for that to happen

  I did not post a pic of the whole facade, but to the right of the plant is an overhang that prevents water from getting on the facade. This section has no overhang so rainwater runs down the facade. A few years ago part of the facade was cracking and I re-rendered that part of the facade. After a rain, the new part of the facade remains bright in color which indicates water does not penetrate. But in the bad area, the gray surface becomes notably darker, which suggests water is penetrating.

  Why can’t you access the upper floor? Is this an apartment building and someone else lives above you?

  I have access to the whole house. The interior pics are of the top floor. What I meant by not accessing the top of the beam is just that the ceiling is in the way. I could remove the drywall on the ceiling corner to get access to more of the beam. I will first dig up the exterior facade and see if that exposes the top of the beam. If not, then I would remove a bit of the ceiling.

  What’s in the black tube?

  I’m not sure what you are referring to. My exteriour pic is terrible (bad camera). On the interior pic, there is a grey cable, probably a/c to the ceiling light. The blackness to the left of that is not a tube but simply a missing brick. It had plaster and insulation foam before I got to it. But now it is just a hole. If you mean the exterior, it’s just a terrible pic. Above the plant is a wood panel that is really warped from getting wet. I installed it new a few years ago but got something wrong. It may not have been treated wood, I don’t recall. I thought painting it would be sufficient but clearly not in the section that has no overhang.

  Perhaps you have already checked, but I’d try to rule out any infiltration coming from above, otherwise it will keep happening and it could get worse.

  I will know more after I dig up the facade. But note that the roof is right above and just to the right of the plant (off picture) is the downspout. It’s clear, but I suppose I have to wonder if it’s possible that water puddles at a bottleneck right where the downspout is.

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  • livligkinkajou@slrpnk.net ⁨1⁩ ⁨month⁩ ago

    Yeah, it might be a good idea to check if the downspout isn’t partially clogged. I don’t know how high that building is, but around here, leaves can get in there every once in a while

    If you haven’t checked yet, you might also want to see the abutment flashing (see #7 below) where that wall and roof meet, as water might be percolating in that area and getting trapped between the ceiling/drywall/insulation.

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    I’d also check the other flashings as well while you are at it and if that drywall and insulation on that affected area are damp, remove them for venting

    I can’t tell too much from the pictures, nor feel and test the wood. You mentioned the plaster was soft, but what about the wood? Are there mycelium growth in it?

    Check if the wood is dark, mushy, deformed, poke test it with a knife/awl/screwdriver, as wood with advanced decay will be soft and the probe will penetrate easily. How far does it go? How big is the beam? Do you know what kind of wood is it? Test in multiple areas

    Tear up a more of the plaster to check how the rest of the beam looks like and test them. If it is less than 0.3 cm, venting might be enough

    Another one is the pick test, where you insert the knife beneath the wood grain to pry loose a thin section of it till it breaks free. If you get a long linear splinter, itś most likely good, if it comes out as crumbly chunks or short pieces with a mushy sound, it is not ideal.

    If you are in a dry season and no rain in sight, I’d clean both inside and outside areas to let them vent. Get a fan/dehumidifier/open windows in that room.

    I also prefer breathable buildings, so you could use a more traditional breathable plaster, which allows water to easily evaporate over time, whereas concrete and all the PVA might help trap the moisture. It is typically made from lime and/or clay, sand, and water. You can also add fibers (horse hair or plant fibers) for strength

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    • diyrebel@lemmy.dbzer0.com ⁨1⁩ ⁨month⁩ ago

      I appreciate all the advice! I still have to dig up the exterior but there is no growth of any kind on the interior side of the beam. It’s drying out and getting less soft as it dries, but still soft enough that I can stick needles in it ~2cm. The bottom side is the softest. I used a syringe to squirt in some wood hardener.

      I am tempted to use pro-grade hydro PVA and plasticizer in the exterior concrete then finish with a waterproofing clearcoat that claims to still allow breathing. I believe that will mitigate rain saturating the facade. But on the inside wall I am tempted to not even plaster and just leave the brick and wood exposed. I would then expect water to not penetrate from the outside, but if it does so anyway then at least it could breath on the inside. I can also monitor it that way.

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