RSJ condensation under plasterboards

[timsterboss]

Hello, today I've seen some patches on plasterboards and it was getting wet without any leakage. Upon further investigation, condensation on steel beems were seen.. before plastering it over, please can someone recommend what it needs to be done? (Appreciate if you can give me a name or link to the materials too)
I don't want to board it and get condensation on RSJ again and ruining new boards...
Thank you

 

[tell80]

If the wall above the RSJ's is an external cavity wall then are cavity trays present?
Is there an extension roof (flat or pitched) abutment above the RSJ's?

FWIW: when you remove plasterboard then dont tear it down - mark and cut out neat squared off pieces.

 

[timsterboss]

Wall above is an ensuite but wall left is external..
Thanks

 

[foxhole]

You can only get condensation with damp air movement, insulation and no air movement would prevent condensation , If it was sealed and insulated and damp then there is a leak .

 

[timsterboss]

It seems the steel beams had no insulation.. should I insulate the beam before I seal it with plasterboards?

 

[freddiemercurystwin]

How do you know there hasn't been a leak?

 

[timsterboss]

There was a leak before but no more leakage now

 

[Nige F]

FWIW: when you remove plasterboard then dont tear it down - mark and cut out neat squared off pieces.

so you can use it again ?

 

[tell80]

So directly above the RSJ's is an en-suite with various possibilities for a hidden, weeping leak.
Carefully inspect under and behind all fixtures in the en-suite - use a powerful light to look up from below.
A posted pic showing the outside might also help?

 

[timsterboss]

Does a beam need insulation?

 

[robinbanks]

Depends on what you mean by "need". If you mean a regulatory need, then no - it only has to be isolated from fire reaching it by eg sufficient thickness plasterboard or intumescent paint

If you mean a need for the good of your pocket, and it connects to an external wall then I'd say yes; you effectively have a large, cold lump of steel acting as a heat sink, transferring your paid-for heat out of your home and potentially collecting condensation while it does so (same principle as how many dehumidifiers work)

If it's not possible to isolate the steel from the cold wall, and having the steel be warm, then you instead turn your attention to insulating the steel from the house so that it remains cold, but the house warmth doesn't reach it