Insulating an apartment wall

VonLuck

One of the bedrooms in my apartment can get colder than the rest of the rooms and it is becoming more apparent now during the colder spell. It's not extremely cold, maybe 16-17 degrees, but other rooms would be in the range of 19-21. I think the main reason is one of the internal walls.

Essentially it is a block wall which has a public corridor / stairs on the opposite side. This public space is not heated so you don't get any benefit of retaining heat like you would if it was a shared wall with another apartment.

Is it bonkers to consider lining my wall with insulation and a new layer of plasterboard to improve the temperature? If it's a runner, what options are out there?

Also, I have a similar situation with the ceiling as a part of it is beneath a roof terrace. I got one of those temperature gun sensors and that section of ceiling is noticeably colder than the rest. I assume there's nothing practical I could do to remedy that, is there?

10-10-20

It's not bonkers in my book, no. Do you own the apartment?

These are the options effectively, with 38mm probably being ideal as there is no exposure to wind/rain on the opposite side of that wall.

https://www.goodwins.ie/insulated-plasterboards/c-1419.html

Ease of application: not so easy unless you're determined. Plus you'd need to plaster afterwards too.

Roughly what temperature is the stairs/corridor?

Kaisr Sose

https://www.boards.ie/discussion/2058275029/insulating-an-apartment-wall

I have a similar problem in my apt. I have a gun as well and the ceiling is cold compared to the walls. Moisture levels are high too. Getting my apt above 18deg is slow and expensive. Reason for all this: most of my apt is below a roof terrace. There is no insulation on the void above my apt. Just plasterboard, air, and the roof slab. This is the outcome of self certification in Ireland.

I thought about ripping the whole ceiling down and putting up insulated boards. Assuming you are the owner, if its just one wall I would do it. It will make a big difference.

VonLuck

https://www.boards.ie/discussion/comment/119971113#Comment_119971113

Yes, it's my apartment. I'm not sure what the corridor temperature is, but it has large glazed windows and no rads so it would get cold in the winter, especially when the windows are sometimes left open to deal with condensation.

38mm is much smaller than I expected! Would there be a noticeable improvement?

https://www.boards.ie/discussion/comment/119971160#Comment_119971160

Why didn't you go ahead with ripping down the ceiling in the end?

10-10-20

You have a third of the loss when using 27mm of ISO (38mm insulated plasterboard) according to this rough calculation.

The plasterboard needs a vapour barrier to reduce any interstitial condensation at the surface of the block.

50mm of plasterboard (38mm of ISO) is roughly:

This won't mitigate any cold bridges at the junction of the wall to ceiling and floor and these may become condensation points if the humidity in the apartment is unmanaged.

VonLuck

That's a very useful tool! Looks like it's definitely worth considering. Material prices are relatively low, but the problem would be trying to get a qualified person to do the work.

Kaisr Sose

https://www.boards.ie/discussion/comment/119971375#Comment_119971375

I am hoping to get this and other issues remidied by the OMC when other defects are being fixed requiring opening of ceilings. I should not have to fund remedial work on what is a violation of building regs (no ceiling insulation)

Otherwise, I would have done it.

I hope you get the result you want with the min thickness of insulation. An interior face or a non external facing wall should not require 50mm, but it's all about how cold the non heated internal space is. My complex internal corridors are not heated either but are not that cold as they are not external facing.

GreeBo

The last line of 10-10-20's is vital to pay attention to and the whole reason I came here to post.

If you dont make sure your alterations are vapour tight you will concentrate all the condensation on a single point and end up with a real mold problem. For this reason I wouldnt use insulated boards, i'd use separate layers of insulation, vapour barrier and then plasterboard, with the VB taped to the corresponding VB (I hope) thats already in your walls, floor and ceiling.

10-10-20

https://www.boards.ie/discussion/comment/119972060#Comment_119972060

That's experience talking. Pay heed.