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Paint bubbling off wood beam DIY help

  1. Apr 6, 2017 #1
    As you can see from the image a vertical portion of my wall (a wood beam) has developed this vertical bubbling where the paint is being rejected. It spans from the ceiling to floor. First thing I thought of was water damage, but as I chip away at the paint and get to the wood it doesn't seem like there is obvious damage, but maybe it's further in the wood? Any other reasons this is happening? Do I simply keep chipping away, then slab a bit of spackle on the plaster and repaint?

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    Last edited: Apr 6, 2017
  2. jcsd
  3. Apr 6, 2017 #2


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    How young is the beam? Fresh or treated wood could gas out.
  4. Apr 6, 2017 #3
    Almost 100 years old :)
  5. Apr 6, 2017 #4


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    Strange. It's too late here now to consult my expert. As the bubbles are along the texture (I assume), there must be a relation. Reminds me a bit on a math joke about a correct but by no means helpful answer. Could it be, that moisture from the paint got into the cracks and dried out later than the rest, namely the surface. Now if the paint is old as well, but the bubbles are not, then it's a real puzzle.
  6. Apr 6, 2017 #5
    I bought the place two years ago as a foreclosure. I know the coat of paint on there now was done fairly recent from when I bought it. I don't remember seeing the bubbling when I bought it. I'm sure I'd remember it and be concerned.
  7. Apr 6, 2017 #6


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    Is it a large area? If not, can you sand it down, make sure it's dry, use a good primer, then re-paint?

    What is on the other side of the wood?
  8. Apr 6, 2017 #7

    The outside, I think either brick or stucco.

    I do have lots of cracks and bubbling in plaster walls on my first floor too I am now noticing. You can one is following a plaster seam and the other a crack. I think my summer project will be stripping several walls. :cry:

    seam1.png seam2.png
  9. Apr 6, 2017 #8


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    Wood expands and contracts as it absorbs humidity. This can occur seasonally.
    More of this kind of size change goes across the grain, relatively little will go the length of the grain or the wood.

    I am not sure that I would call your first picture bubble rather than folding up of paint with the underlying wood has shrunk.
    Bubbling I have seem has more of a rounded top (due to pressure inside the bubble) while your picture seems to show a series of peaks.

    Size changes of wood framing might also explain the cracks at drywall seams if the panels are moving independently.

    Where I live there are also movements of the ground as the clay soil expands when it is wet and contracts when it dries out. Depending on how you house is constructed, this kind of thing can move the whole house or parts of it.
  10. Apr 6, 2017 #9


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    If you were closer, I would wobble over and help, I love doing this kind of thing. When my first husband was in the Navy, we spent several years in condemned military housing that was built as temporary shelter after WWI. I'll never forget the day the bathroom wall fell off the house. I walked down to the maintenance shed and told the guy, he went to the back and came out with a box of tiles and a bucket of grout and handed them to me. I said, no, you don't understand, there is no wall to put these on. He gave me a crazy look. Locked the shed, and walked back to my hovel with me, we went inside and when we entered the bathroom and there was just a gaping hole he goes "WHAT DID YOU DO?"

    My neighbor fell through her living room floor and broke her ankle.

    So, it could be worse Greg. :biggrin:
  11. Apr 6, 2017 #10


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    I think it's due to the usual movements of wood, esp. if there are temperature or moisture differences involved. In German we say "wood works".
  12. Apr 6, 2017 #11


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    What's the material under the surface in these two images? I'm not any expert on plaster, but it seems unusual to have plaster applied directly to a wood beam. The usual substrate for plaster is wood strips (laths) and/or a kind of chickenwire mesh. I'm wondering if the wood beam in the picture in post #1 is picking up moisture from outside, causing it to expand and generate cracks on the inside surface, along the lines of what @fresh_42 said about wood "working." I don't think the moisture would necessarily be in the form of liquid water - vapor could pass though without the wood seeming to be very wet.

    Another possibility that might make sense is that the humidity inside the house is a lot less than outside, which would cause moisture to migrate from the wetter side to the drier side. If you heat with wood, the humidity inside can be very low. Where I live (WA state), the humidity in the house was in the low 30% range in our coldest weather.

    Since the place was a foreclosure, the bank might have hired someone to make fast, cheap repairs, which might not have included good surface prep or a good primer coat -- the result being that the paint or plaster isn't adhering well to the wood.
  13. Apr 6, 2017 #12
    Yeah that is correct

    lol your post I know wasn't meant to be funny, but I did laugh because it sounds ridiculous :biggrin:
  14. Apr 6, 2017 #13


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    yes and ensure the surface is free of oils.... natural from the wood or otherwise

    OK and how long ago was it painted with this current coating ?
    if less than say around 5 yrs since pained then look for poorly prepared surface
    if painted much longer than 5 ++ years, then the pain could be failing naturally or because of environment

  15. Apr 6, 2017 #14
    The first photo is a wood support beam. The next two are plaster.

    I have water rads with a boiler. The inside humidity was low 30s all winter and still is.
    Last edited: Apr 6, 2017
  16. Apr 6, 2017 #15
    I'd say 2 years ago done by the flipper. Yeah I know. I am paying the price for many of the cheap fixes by the flipper.
  17. Apr 6, 2017 #16


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    the flipper --- isn't a term I'm familiar with here in Oz

    Our bathroom has similar problems, pain is peeling badly .... the landlords father repainted the ceiling 5 yrs ago but he didn't clean the old paint surface properly
    the new paint was starting to peel in 12 months and then ongoing ingress of steam from the shower and the pain is a total mouldy mess

    Every time I try to clean the mould off, more paint just peels off

  18. Apr 6, 2017 #17


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    I'd blame it on the painter - probably didn't use any primer, didn't properly sand before painting, and the adhesion was poor, making your paint more susceptible to 'wood works'.

    Flipper refers to the investor who bought the house, did a crappy paint job, and sold it to a physicist. ;-)


    I did a little googling, latex over oil is blamed here -

    Last edited: Apr 6, 2017
  19. Apr 6, 2017 #18
    I'm not a physicist :)

    That is likely. There are many coats and certainly the first few must be oil or some older mixture.
  20. Apr 6, 2017 #19
    I grew up in a house over 100 years old and I remember that happening to paint in our house too. Old houses move around a lot, does that wall creak in the wind?
  21. Apr 7, 2017 #20
    It looks like poor prep work. Walls can pickup oils and waxes and other stains that will inhibit paint from adhering properly.
    The remedy is to strip off the bad paint and wash the walls with trisodium phosphate or borax and repaint.
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