Built in wardrobes on gable wall - what kind of insulation needed

CarPark2 · 15-06-2020 12:16PM #1

I am a total novice at this and don't want to risk damaging the house through mould, condensation etc.

We have a timber frame house, built ~ 2005. We bought it 3 years ago.
It has holes to the outside (see pic).

I would like to fit a built-in wardrobe against the gable end wall, and have two considerations.
1. The insulation in the house is not great and we are considering getting internal insulation fitted in the long term. We are waiting until next winter to get a house heat survey completed and get advice from that. However, we wish to go ahead with the built-in wardrobe in the meantime. So rather than fitting that now, and ending up having to remove it in order to fit insulation behind it, we were thinking of getting the insulation fitted now.

2. I am conscious that fitting a wardrobe to a gable end wall might lead to condensation or damp between the wardrobe and the wall. Is that a risk? Is there anything (including insulation or something else) that we could fit between the wall and the wardrobe to prevent that?

Can you advise on what we should put between the wardrobe and the gable wall in order to ensure good insulation and prevent any condensation build up or mould etc. growing?

Calahonda52 · 15-06-2020 02:16PM

what other ventilation is there in the house, these vents are just for the facade and not for the rooms?

CarPark2 · 15-06-2020 02:21PM

Thanks for responding.

We have the normal hole-in-the-wall covered by a grid on both sides. These are in most rooms, but strangely absent in that room. At the moment, there is plenty of ventilation provided by the windows not being very well sealed. We do plan to get that seen to over time.
Just to note, although i said wardrobe, this not a bedroom. It is a second living room. We want the "wardrobe" for storage of toys etc., not clothes. There is no fireplace or other combustion in the room.
At the moment, there are no problems at all with mold or condensation.

Calahonda52 · 15-06-2020 04:18PM

Are you going floor to ceiling with the kit?
You could leave the back of the units open and add ventilation holes in the kickboard and on the top of the unit, or a variation thereof.
I am not a huge fan of adding more insulation onto the existing plaster board.
While you are at it, take off a wall vent and see is the vent sleeved and sealed to the plaster board on the inside

Pinch Flat · 15-06-2020 04:26PM

I live in a cavity block built house it's dry lined with Rockwood internally. So probably much worse than yours from an insulation point of view. The gable bedroom we could never keep warm. I put a wardrobe up against it and bought some 10mm sheets of aeroboard that I pinned to the wall before putting the wardrobe up. Not ideal but has definitely helped.

Calahonda52 · 15-06-2020 04:30PM

Pinch Flat wrote: »

I live in a cavity block built house it's dry lined with Rockwood internally. So probably much worse than yours from an insulation point of view. The gable bedroom we could never keep warm. I put a wardrobe up against it and bought some 10mm sheets of aeroboard that I pinned to the wall before putting the wardrobe up. Not ideal but has definitely helped.

Yes but what mould if any is growing on the wall behind the aero?

CarPark2 · 15-06-2020 04:41PM

Thanks for responding.

Calahonda52 wrote: »

Are you going floor to ceiling with the kit?

Close to ceiling, but these things usually tend to finish a bit below the ceiling. Haven't decided on design yet. We will be getting somebody to do it.

Calahonda52 wrote: »

You could leave the back of the units open and add ventilation holes in the kickboard and on the top of the unit, or a variation thereof.

How do you mean "leave the back of the units open"?

Calahonda52 wrote: »

I am not a huge fan of adding more insulation onto the existing plaster board.

Why?
It is a fairly cold house. I know that there can be lots of reasons for that, and we will look into that in the winter when we get a heat loss survey, but if that suggests that we don't have enough insulation, i don't want to have to remove the wardrobe, add insulation and then put the wardrobe back in place. Would it not be a relatively low cost solution now?

Calahonda52 · 15-06-2020 04:48PM

the skimmed pb is vapour proof and is a medium for mould growth which may happen if the dew point is reached behind the new insulation.

You need to address the cold house question first so have you taken off the wall vent?
Open because it would allow air movement against the wall

CarPark2 · 15-06-2020 10:36PM

Calahonda52 wrote: »

the skimmed pb is vapour proof and is a medium for mould growth which may happen if the dew point is reached behind the new insulation.

So is there a way of improving the insulation of a timber frame house? If, for instance, all other issues were addressed and we found it was still cold is there a way of improving the insulation? Would we need to remove the current plaster board and replace with insulation + plaster board + skim?

Calahonda52 wrote: »

You need to address the cold house question first so have you taken off the wall vent?

I'll do that tomorrow and update.

Calahonda52 wrote: »

Open because it would allow air movement against the wall

By "open" do you mean that there would be a gap between the unit and the wall or that there would not be a back on the unit?

I grew up in a block built house, with a cavity, but probably no insulation. If we put a bed, bookcase or free-standing wardrobe against the wall, we would end up with mold on the wall behind whatever furniture was against the wall. Would that also happen here, even if there is a small gap between the unit and the wall (maybe it was more a feature of a 1970's bungalow)?

BryanF · 16-06-2020 07:06AM

CarPark2 wrote: »

So is there a way of improving the insulation of a timber frame house? If, for instance, all other issues were addressed and we found it was still cold is there a way of improving the insulation? Would we need to remove the current plaster board and replace with insulation + plaster board + skim?

Yes. A New vapour barrier (air-tightness) taped and sealed would be required. Trying to ensure this is continuous will make this job something your average plasterboarder will not be suitable for. Costs of this approach, trying to seek any kind of continuity, won’t be cheap as it will be invasive to finishes in your home.

Lumen · 16-06-2020 08:20AM

I'm facing exactly the same task, except I have a block cavity wall.

I'm considering using woodfibre insulation butted hard against the internal wall with strong battens, covering with wooden slats, and then mounting new open-backed wardrobes through the slats on to the battens. Then when you open the wardrobes you will see attractive wooden slats.

There would not be a VCL as such, but the breathability of the structure ought to prevent interstitial condensation.

What do you think, experts?

CarPark2 · 16-06-2020 08:32AM

So i checked the vent. There seems to just be an opening on the inside and an opening to the outside. No pipe going through the wall. So it seems to be open to the cavity. Also found a dead bird in there, so i presume that it opens all the way up to the attic (we tend to get starlings in the attic).

Image below (i removed the bird first!).

Calahonda52 · 16-06-2020 09:02AM

Excellent work with the picture thank you.
Now you see that the first project is to stop all that cold air getting in at the back of the plaster board.

I will be back later with a plan

BryanF · 16-06-2020 05:44PM

Lumen wrote: »

I'm facing exactly the same task, except I have a block cavity wall.

I'm considering using woodfibre insulation butted hard against the internal wall with strong battens, covering with wooden slats, and then mounting new open-backed wardrobes through the slats on to the battens. Then when you open the wardrobes you will see attractive wooden slats.

There would not be a VCL as such, but the breathability of the structure ought to prevent interstitial condensation.

What do you think, experts?

not much. Walls not breathable.

Is it block/cavity/block?

Lumen · 16-06-2020 05:52PM

BryanF wrote: »

not much. Walls not breathable.

Is it block/cavity/block?

Yes, and the wall is plastered on both sides. I'm OK at wood bothering and trying to stay in my competence zone. No skills with plaster and prefer to minimize use of foam insulation.

I was going to run the insulation down below the subfloor to achieve as much continuity as possible.

Would slapping some Intello Plus over the woodfibre help?

BryanF · 16-06-2020 08:18PM

Lumen wrote: »

Yes, and the wall is plastered on both sides. I'm OK at wood bothering and trying to stay in my competence zone. No skills with plaster and prefer to minimize use of foam insulation.

I was going to run the insulation down below the subfloor to achieve as much continuity as possible.

Would slapping some Intello Plus over the woodfibre help?

I’m all for natural materials and far play to you. Before you go with about barrier, what width is the cavity and have you filled it with beads? If your using say 60mm gutex and the cavity is say 100mm and filled, inn not aure I’d bother with a vapour barrier considering you no guarantee of continuity, and the due point will likely be in cavity. Assuming your getting your wood fibre from an Irish distributor they may offer you a wufi calc?

Built in wardrobes on gable wall - what kind of insulation needed

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