Vapor barrier 70s house

[Simonjhn]

Hello!

I'm in the middle of renovating our 70s brick house (our first) with everything that entails. My concern is whether I've made a mistake by not installing a vapor barrier/plastic on one of the bedroom's interior walls facing the external wall. I've replaced the base plate/studs and windows, added new insulation, and then just put up drywall on which is now plastered and sanded...
On the old drywall, there was plastic on the backside, which I noticed a little too late... Is it just a matter of tearing it down and redoing it?

Thankful for a response
//Simon

 

[Elvvsbygg]

Response from a layperson here. One option is to put a vapor barrier on the gypsum and screw on an additional layer of gypsum over that. Without a vapor barrier, you risk the moisture content in the insulation becoming high after a few years with poorer insulating capability and risk of mold on wooden studs, worse the further out towards the cold side you get.

 

[Jonatan79]

I wouldn't have done that, many houses similar to yours have no plastic in the roof or walls and it works fine. Do you know how thick the insulation is?

 

[Simonjhn]

I wouldn't have done that, many houses like yours don't have plastic in the ceiling or walls and it works well. Do you know how thick the insulation is?

The reason I removed the old one was mainly to replace the sill preventively as it was directly against the slab. But there weren't any direct problems with smell or moisture damage. I just get extremely paranoid since there was plastic before and not now.
Yes, the insulation I have installed is Isover 95mm glass wool. The wall itself is built as follows: brick, then air gap, then there is a very thin insulation on the wind board (against the brick side), then studs/insulation and gypsum.

 

[Elvvsbygg]

Yes, there are many considerations here and it's not easy to give 100% advice. Try without plastic for 2 years and then open and inspect.
You always have some guilty conscience with some DIY work you've done.

 

[Simonjhn]

Have spoken with 3 different carpenters and they believe it shouldn't be a problem, but they mentioned that stone wool insulation is preferable if you go without plastic. Then one of them said to use plastic if you redo it, but he also had a similar brick house built in '73 and he has no plastic. So I’ll leave it as it is and see how it goes. Thanks to those who responded!! Now I can refocus on laying floorboards on the subfloor.