Errrrr... Condensation.

[Paul5454]

Hi!
Bought an old 3 storey house with an elderley utility room extension.
Roof is single pitch and tiled. No idea if it's insulated, cos no way of gaining access.
3 walls are exposed, cavity with air bricks.
Obviously, as a utility room there's a dishwasher, washing machine and sink in there.
All 3 walls are wet through now, and mouldy. Time of year, I know.
I'd like to know what you think are my best options. I've searched and found several.

1. Cavity insulation. Small room - 25 cubic yards (don't understand metres). Could be expensive for such a small job?

2. Internal insulation. (Visqueen on walls, battens, Kingspan, plasterboard.)

3. Dehumidifier. WHICH tested 9 of them. Their top 2 recommended were still crap and over £200.

4. Dehumidifying extractor fan. No idea how good they are.

5. Bog standard extractor fan? I know ventilation is key, but it seems to me that will just make it cold to 'live' in?

I have an electric oil filled radiator on nearly all day and the door closed. There's no ventilation in there without opening doors and windows. The next room is the kitchen, and we try to keep the door closed because of the vapours from cooking.

I've researched, as you can see, but I wondered what you thought would be the best solution, if there is one.

Thanks for any help you can give.

Paul.

 

[Architexeter]

2, 5 & heat

 

[JohnD]

How thick, exactly, are the walls?

How good is the ceiling plaster? What is the headroom?

Is the floor damp?

 

[Paul5454]

Thanks for the replies.

The walls are brick with a 12" cavity.
The ceiling is good and 8' high.
The floor is dry.

Paul

 

[jeds]

2. Internal insulation. (Visqueen on walls, battens, Kingspan, plasterboard.)

Internal insulation good. Spec bad. Visqueen should be placed between plasterboard and insulation.

Even better spec is thermal laminate plasterboard fixed direct to wall. No cavity required. Humidistat extractor fan is also good but get one with an adjustable stat. Otherwise they run constantly.

 

[tony1851]

The walls are brick with a 12" cavity.

 

[KenGMac]

I am with Tony here

There is a question over the width of the cavity? ? ?

A couple of things, ease to prove [or not]

You note the presence of "Air bricks" if you take a torch and have a look into the "Air Brick" to see if there is an "internal liner" ? why, because if there is no liner that will mean that air entering the ""Air Brick" will circulate within the cavity thus negating the intention and properties of a "Cavity"
The "cavity" is supposed to be a still area of air, not itself vented this allows air to do what it is good at that is an insulator.

On the other hand, if you are still reading this, is the cavity already Insulated? you mention in your post that the "extension is not new? I have seen several cases [during last winter] where the "old" cavity insulation has failed "BADLY" the insulation failure had resulted in an entire gable [facing the prevailing wind was saturated inside the 4 / 5 rooms of the property, paper peeling, plaster failing Etc. I hope you get the picture?

Bottom line? until you [if you can] confirm the above then a route to prevention MAY be futile, a bit more info if possible please?

Ken.

 

[Static]

Why not simply leave the windows open?

 

[AronSearle]

Some things to consider.

A dessicant dehumidifiyer will produce heat, as well as dry the air (a condensing dehumidifiyer does not produce much heat, and works poorly at low temperatures), if you do the numbers you might find for a small room, it's about the same running cost to run a DH rather than the oil heater, but it also dries the air, a decent one will possibly do adjacent rooms as well if the door is left open.

If you do go down this route, think about air tightness (no point wasting money drying outside air), light fittings, skirtings, window surrounds, the window itself, plug socket surrounds (yes really), can all be points for air infiltration, go mastic happy.

When it comes to air tightness and air briks, bear in mind what KenGMac said.

As to insulating the cavity, the problem could be cold bridging.

If you insulate the cavity, and can't access the roof, it's likely there will be a gap at the inside ceiling corner where the wall and roof meet. So from that perspective it may be better to internally insulate both the walls and ceilings, that way you can ensure no gaps, where cold bridges mean condensation would still occur.

If you insulate you will still need ventillation, but again, you might find it cheaper overall to insulate, attain good airtightness, and run a dehumidifiyer rather than ventillate.

Why not simply leave the windows open?

Because it's 2013, not 1913?

 

[JohnD]

A utility room, suffering bad condensation?

Even in 2013, ventilation is the cheapest, simplest and most effective cure.

 

[AronSearle]

A utility room, suffering bad condensation?

Even in 2013, ventilation is the cheapest, simplest and most effective cure.

Not necessarly, especially if you want to dry clothes in the room.

You'll be paying to constantly heat new air, and that cold will leak into the rest of the building.

Ventillation is the cheapest and quickest in the short term only.

 

[JohnD]

especially if you want to dry clothes in the room.

you mean, add vast quantities of water vapour to the room?

A splendid way to increase condensation, damp and mould.

 

[AronSearle]

especially if you want to dry clothes in the room.

you mean, add vast quantities of water vapour to the room?

A splendid way to increase condensation, damp and mould.

And exactly what most people use utility rooms for, not everyone has an outdoor space, or wants to use it, especially in winter.

Make the building work for you, not the other way round.

 

[JohnD]

the OP was not asking for the best way to cause condensation, he was asking how to get rid of it. So the answer is ventilation.

 

[AronSearle]

So how come I have no condensation issues, but dry all my clothes indoors?

hmmm?

Besides, I'm only assuming he dries his cloths in there, it may simply be the washing machine/dishwasher causing the moisture.

He's already heating the room with an oil heater, he could run a dehumidifiyer for practically the same running cost, and if he makes it more air tight, possibly cheaper.