Damp condensation in built-in wardrobe

[steveoelliott]

Hi Folks,

 

I have an issue with damp or more specifically condensation in a built in wardrobe in a north facing bedroom. This is a 1960s house. I have attached a picture merely for perspective.

This wardrobe, in the winter months has caused issues with some clothes feeling damp / smelling musty. Upon my own investigation I discovered that particularly the corner where the two outer walls meet the ceiling is especially cold and feels damp. This is always worse when the weather outside is particularly cold. It's never an issue in the warmer months.

 

My understanding of this is as follows. The room itself might be warm but the internals of the wardrobe with the doors closed remains cold. When the warm / moist air from the room gets into the wardrobe through the gaps around doors etc. it hits the cold walls / ceiling and condenses causing the moisture. As a workaround I have placed numerous dehumidifier pots in there which seem to help significantly but I am after a proper solution. The outside walls are solid brick with plaster (not dot and dab) and whilst there is cavity wall insulation, those walls in the wardrobe and ceiling are cold to touch. I have checked the loft and there is plenty of insulation above as in it isn't like the corners have less present etc.

When we decorate this room, I am wondering what my options are. I wondered if I could add some kind of thermal boarding (if something like that exists) to the inside of the wardrobe.

 

Appreciate any help you can offer.

Edited Wednesday at 17:29 by steveoelliott

[Nickfromwales]

19 hours ago, steveoelliott said:

Hi Folks,

 

I have an issue with damp or more specifically condensation in a built in wardrobe in a north facing bedroom. This is a 1960s house. I have attached a picture merely for perspective.

This wardrobe, in the winter months has caused issues with some clothes feeling damp / smelling musty. Upon my own investigation I discovered that particularly the corner where the two outer walls meet the ceiling is especially cold and feels damp. This is always worse when the weather outside is particularly cold. It's never an issue in the warmer months.

 

My understanding of this is as follows. The room itself might be warm but the internals of the wardrobe with the doors closed remains cold. When the warm / moist air from the room gets into the wardrobe through the gaps around doors etc. it hits the cold walls / ceiling and condenses causing the moisture. As a workaround I have placed numerous dehumidifier pots in there which seem to help significantly but I am after a proper solution. The outside walls are solid brick with plaster (not dot and dab) and whilst there is cavity wall insulation, those walls in the wardrobe and ceiling are cold to touch. I have checked the loft and there is plenty of insulation above as in it isn't like the corners have less present etc.

When we decorate this room, I am wondering what my options are. I wondered if I could add some kind of thermal boarding (if something like that exists) to the inside of the wardrobe.

 

Appreciate any help you can offer.

Had this exact thig on a job a long time ago, and just hacked off all the inside of the cupboard and replaced with 25mm insulated PB, ensuring all edges of the PB met PIR not cold walls. I foamed all the gaps, tops / sides / bottom, so no cold air could travel behind, and job done.

 

Adding vents to the doors won't do much as there's clothes preventing air circulation.

[steveoelliott]

3 hours ago, Nickfromwales said:

Had this exact thig on a job a long time ago, and just hacked off all the inside of the cupboard and replaced with 25mm insulated PB, ensuring all edges of the PB met PIR not cold walls. I foamed all the gaps, tops / sides / bottom, so no cold air could travel behind, and job done.

 

Adding vents to the doors won't do much as there's clothes preventing air circulation.

Thank you

When you say hacked off, do you mean you went back to brick? This isn't plasterboard apart from the front and right hand side (which are much warmer) which are stud walls.

 

I suspect, I could overboard with the insulated plasterboard, sealing the gaps and then take the slight loss of space on the ceiling and walls which would be minimal.

[Nickfromwales]

4 minutes ago, steveoelliott said:

Thank you

When you say hacked off, do you mean you went back to brick? This isn't plasterboard apart from the front and right hand side (which are much warmer) which are stud walls.

 

I suspect, I could overboard with the insulated plasterboard, sealing the gaps and then take the slight loss of space on the ceiling and walls which would be minimal.

Yes, I hacked off as the plaster and mortar was damp, plus they didn't want to lose an ounce of space.

 

You defo do not want voids and layers, so do this meticulously or not at all.

[steveoelliott]

Just now, Nickfromwales said:

Yes, I hacked off as the plaster and mortar was damp, plus they didn't want to lose an ounce of space.

Noted. Mine isn't that bad. The plasterboard on the coldest section of the ceiling is still sound.

[Nickfromwales]

2 hours ago, steveoelliott said:

Noted. Mine isn't that bad. The plasterboard on the coldest section of the ceiling is still sound.

I’d do the ceiling too. 

[steveoelliott]

18 hours ago, Nickfromwales said:

I’d do the ceiling too. 

Yes I intend to given it is very cold towards the corner.. I'd take advice from a plasterer whether I should rip out the exiting ceiling within the wardrobe or overboard it.

[Nickfromwales]

5 minutes ago, steveoelliott said:

Yes I intend to given it is very cold towards the corner.. I'd take advice from a plasterer whether I should rip out the exiting ceiling within the wardrobe or overboard it.

As long as none of the new boards touch the cold structure, or are in immediate contact with the cold corner of the ceiling, then you'll be fine.

 

Boand and screw 12,5mm or 15mm Marmox to the ceiling first, over boarding the existing PB so the dust and shit up the attic stays up there, and you can skim directly over that when the boarding is all done and you're ready for a spread. Butt the new insulated PB to the Marmox, then you are warm / warm and will have zero issues.

[steveoelliott]

On 27/02/2026 at 13:22, Nickfromwales said:

As long as none of the new boards touch the cold structure, or are in immediate contact with the cold corner of the ceiling, then you'll be fine.

 

Boand and screw 12,5mm or 15mm Marmox to the ceiling first, over boarding the existing PB so the dust and shit up the attic stays up there, and you can skim directly over that when the boarding is all done and you're ready for a spread. Butt the new insulated PB to the Marmox, then you are warm / warm and will have zero issues.

Thank you  As I will need to redo the battening / shelves / rail etc. given the change in configuration, what did you use to fix through the insulated PB? I guess you could use those corefix fittings or (as I have done with dot and dab elsewhere) drive the plug into the brick wall behind and put a second in place within the PB and then use a long screw.

Edited 7 hours ago by steveoelliott