OSB behind the reveal board and under marble?

[swealp]

Hello!
Our carpenter has screwed OSB boards behind where the reveal board should be and under the window sill. (Inside).

Is this really correct? It feels like OSB can swell, especially when it's right by the window.

We were planning to have a marble sill and reveal board made of MDF.

Thanks for the tips.

Not my picture, but it looks exactly the same.

 

[vojma]

He will probably mount (glue) an MDF strip onto the OSB.

I do that sometimes.

 

[swealp]

OSB doesn't feel good at all to have under marble and behind MDF, it doesn't work particularly well with moisture/cold.

I also can't find any construction examples with OSB board around windows.

I would gratefully receive more answers.

 

[Pumba]

Our housing supplier used green (pressure-treated?) chipboard in the window recess, but we chose to use spacers made of oil-hardened board, like Masonite, which are attached in strips behind it as I wasn't comfortable with that chipboard.

I don't think there's any risk as it's done in the pictures.

 

[swealp]

Our house supplier used green (pressure-treated?) particle board in the window jamb, but we chose to make spacers from oil-hardened board, like Masonite, which are in strips behind because I wasn't comfortable with that particle board.

I don't think there's any danger with how it's done in the pictures.

Why weren't you comfortable with pressure-treated particle board? It sounds like the best choice I've heard (so far) ??

Regards

 

[Pumba]

Why weren't you comfortable with pressure-impregnated particle board? It sounds like the best choice I've heard (so far) ??

regards

Didn't think it belonged indoors

 

[swealp]

Didn't think it belonged indoors

Hmmm, probably this one they intended to use:

-Moisture-resistant particleboard
A board manufactured with waterproof glue. It is not impregnated. Often colored green for easier distinction from regular particleboard. Preferably used in areas where you suspect temporary moisture increase.

Source:
https://www.beijerbygg.se/store/pri...krivningar-bradgard/olika-typer-av-spånskivor

 

[hul]

What would be wrong with that construction?
you shouldn't expect penetrating moisture, should you? Can't expect a construction defect.
with that mindset, you would have to replace all materials since moisture can get in

 

[swealp]

What would be wrong with that construction? You shouldn't expect any penetrating moisture? You can't assume a construction error. With that mindset, you would have to replace all materials since moisture could get in

I haven't found any construction drawings or construction examples with OSB, hence the question.

Träguiden runs completely without anything underneath:
* https://www.traguiden.se/konstrukti...-i-tva-skikt--alt-2-horisontalsnitt-rak-smyg/
* https://www.traguiden.se/konstrukti...va-skikt--alt-1-horisontalsnitt-vinklad-smyg/

 

[swealp]

It is barely possible to find the "slightly more moisture-resistant particle board," it seems no one uses it.

I will have to settle for P30 (K-plywood 20/70) if I can't find anything better.

Thank you

 

[Slarvpellen]

So if you suspect that you will have moisture in the window recess or under the windowsill, I think you should review your construction methods and/or window choice.

Also, I don't understand why OSB would be more moisture sensitive than MDF, which apparently felt more okay. MDF and water is a disaster if that's news to anyone.

 

[swealp]

So if you suspect that you will have moisture in the window recess or under the windowsill, I think you should review your building methods and/or window choice.

Also, I don't understand why OSB would be more moisture sensitive than MDF, which apparently felt more okay. MDF and water is a disaster if that's news to you.

There are both moisture-resistant and waterproof MDF boards.

Since there is a ventilation gap in the window, it feels better if you have a more steam-resistant board compared to OSB. There is plywood that can withstand up to 80% steam. Now we're talking steam, not direct moisture.

Yes, I can partially agree that it might not be necessary.