Wallrock Thermal Liner (as insulation)

[cwhaley]

Hi all.

Just wondering about Wallrock as insulation. I've been gradually tackling the condensation/mould in our house. It has 9" solid brick, so North-facing walls can be pretty cold. Solution for me was to strip plaster off, put battens up, fill with Celotex sheets and plasterboard over. Rooms are warmer, no cold wall for the water vapour to dew on and I've even cleaned the trickle vents to improve ventilation for that vapour to escape.

The last (and worst) room though is the bathroom. It has two external walls, one of which suffers very badly from mould and it's not good for the old asthma! First job is to insulate the toilet cistern with foam (to stop water beading on the outside), the last job is to insulate the walls... and this is where I need some advice.

I don't fancy losing 45mm+ of space for Celotex/plasterboard again, so I was wondering about the effectiveness of Wallrock? Believe it's only 3-4mm thick but made from wood/fabric fibres interwoven together... Has anybody used this stuff? Only need it to make the walls a little warmer so condensation doesn't dew on it.

Just looking out there to hear of any experience of it really! Thanks.

 

[JohnD]

First job is ....

To provide ventilation, such as an extractor fan, to whisk away the water vapour.

 

[cwhaley]

Thanks for the reply, but there is plenty of ventilation in there (extractor fan and a window fully wide open when showering). The amount of water vapour released from a hot shower is far too much to be simply whisked away.

The issue is the cold walls - water vapour simply condenses on it before all of it reaches the vent or window.

 

[foxhole]

Sounds like fan is under power and poorly positioned . Done correctly you get no moist air hitting walls .

 

[JohnD]

For a bathroom, an extractor fan works effectively if the door and window are shut.

This means that the air will be still, not swirling around and mixing.

The water vapour, being lighter than air, will rise towards the ceiling, where the fan will suck it outside. The suction will draw dry, room-temperature air through the gap under the door, it will lie under the moist air and replace it as the moist air is drawn out.

The suction will prevent the water vapour from diffusing into the house.

The window being closed will prevent air flowing in through the window and pushing the water vapour into the house.

 

[cwhaley]

I see what you're saying and respect/understand your explanation but I have tried closing the window on a 2 week trial but to no avail; honestly I've tried many ways of dealing with it, but every property is unique. The extractor fan is a large unit and completely clean and free from obstruction, however it's clearly not working and cannot shift the volume of moisture from the air.

The walls are very cold because of the lack of insulation. I'm trying to cure the cold wall problem and I'm exploring different means of insulting the walls.

Really - I just need to know if Wallrock is any good based on the experience of others. Another fan alongside the one I have is a bit of an overkill for a room only ~4' x ~7' in size. If I can warm the walls better, there's less places for moisture to sit.

 

[foxhole]

Warming the walls is totally impractical.You will still get condensation on any tiled areas and the windows.I have a fully tiled shower room and get zero condensation, have high power fan extraction which does the job easily.You said you have a large fan , rather a vague description? I previously used two vents connected to one big fan to ensure rapid removal of damp air, you could add another to yours?

 

[cwhaley]

Thanks for the reply.

Honestly Without going into the fan's dimensions and specifics - the main issue I have is cold walls and I'm trying to find out if Wallrock is worthwhile. I'm not bothered about condensation on the tiles as it simply runs off or eventually evaporates. It's the cold, painted walls which instantly attract condensation before it can rise towards the fan or any vent and I want to sort that before looking at a second or replacement fan. Not ruling out the extractor fan route but want to try this first.

I do fully understand what you're describing but I'm really just trying to understand if Wallrock has been tried and tested by anybody here.

 

[foxhole]

You can lead a horse to water .!!

 

[JohnD]

wallrock is fancy wallpaper.

Consider that your loft insulation will be between 100mm and 250mm thick.

Cavity wall insulation, if you have it, will be between 50mm and 100mm

Compared to proper insulation, a padded wallpaper is negligible (except in cost)