Insulating behind fitted wardrobe

[redsturgeon]

I know this is related to the bedroom insulation question but I thought it best to ask separately.

We are thinking of having some fitted wardrobes built across one wall of out bedroom (Mrs RS being fed up with trying to cram all her clothes into a free standing Victorian antique) . As luck would have it, this happens to be the only external wall in the room. I was wondering if we are likely to risk damp forming in the back of the wardrobe and whether it is worth insulating inside the wall before fitting the wardrobes.

The wall are double skin brick with blown wool insulation and it is a North facing wall.

John

[ten0rman]

20+ years ago I installed some fitted wardrobes against northwest and northeast facing external, insulated, walls. Just to be sure, I used melamine faced chipboard inside the wardrobe back, sides and base thus leaving a gap between the chipboard and the walls & floor. As far as I can tell from a quick look just now, all is well. What it's like on the actual walls I have no idea.

From what I remember, the reason for doing this was because of condensation/black mould issues in our previous house, although it has to be said that the previous house was storage heaters & electric fires, whilst the current house is storage heaters and an open coal fire, and I've a suspicion that the draught from the open fire helps get rid of the damp air.

Our kitchen is similar in that there is a gap between the back of the units and the wall. Looking through the inevitable gaps for pipework, the original walls look dirty, but that's all. This is on a north-east facing insulated external wall.

FWIW, I don't remember what the insulation is, other than I think it was blown in.

HTH

ten0rman

[dspp]

rs,

I have been in houses where rooms and spaces with 'dead' immobile air against cold external walls went damp and mouldy. These included in cupboards such as you describe. I fixed them by fitting insulated plasterboard. I never found a hanging cupboard that was too narrow to accept some insulated PB - in extremis the hangers just sit squint. It worked in all instances. Typically I used 40-60mm width insulation in these areas, though where I could I went to 100mm insulation. As a bonus you end up with a warmer room as well as no damp & musty/mouldy issues in the clothes.

regards,
dspp

[PrincessB]

The wall are double skin brick with blown wool insulation and it is a North facing wall.

Extra insulation would not be that high on my list for that kind of wall structure.

The walls that cause problems are stone or solid brick as their instulation values are dreadful. To give some kind of comparison, your filled cavity wall would insulate around seven times better than solid brick.

Admittedly, the wall is going to be colder on that side of the houses so regardless of insulation values, you're going to want some airflow to take the warm air of the room and ensure it moves every so gently through the wardrobe.

With that in mind (and were it my project) I would not go much further than ensuring the wardrobes has some discrete vent or louvres (with a dust filter if you desire) top and bottom to allow airflow.

You could batten the wall with vertical slats and fix the wardrobes onto the slats to ensure the back of the units is not in direct contact with the walls - You would also ensure that airflow is possible behind the wardrobes up and through the louvred area which in essence ensures the only air in contact with the back of the wardrobes is cooler room air rather than icy wall air.

If it helps, I've got a large (and ghastly) free standing Ikea wardrobe set against two of the external walls in the corner of the bedroom that gets practically no sun. Air gap is about 75mm at the back and another 100mm to the right. My wall insulation is only half as good as yours and there's not a spot of mould back there.

Regards,

B.