Insulating an internal wall

[robpamsut]

Hi

I have a porch extension on the front of my house that has a small toilet room as part of it. The two walls of the toilet that are the outside of the extension have very bad condensation with mould growth and paint peeling off (as does the other wall in the porch). There is no cavity in the walls.

I have been advised that I need a new double glazed window in the room with a trickle vent, which I have had a quote for. Also suggested removing the old paint, putting a water sealant on the wall, then some polystyrene insulation directly onto that then wallpapering and painting with a kitchen/bathroom paint.

My question is, does this seem like a good plan and if so any suggestions on a sealant and a particular insulation board brand? The insulation has to be thin, 25mm, as the toilet room is incredibly narrow.

Many thanks
Rob

 

[noseall]

25mm isn't much but better than nowt. Question is, will it do the job.

The problem you have is condensation, no paint or water sealant is ever going to do owt.

If using only 25mm of insulation then use celotex or kingspan.

How thick are the external walls?

 

[robpamsut]

Thanks for the advice.

The walls are thin just brick and then plastered, sorry not much knowledge when it comes to construction. I guess the advice regarding the bathroom paint was that the condensation which would hopefully be reduced would be easier to wipe off and thus eliminating the mould build up. The floors are really old small red tiles that are incredibly cold, would putting rubber tiles down make any difference or is it all down to the freezing cold walls?

Also I looked at the Celotex website, any particular type is best?

 

[wwwebber]

Also I looked at the Celotex website, any particular type is best?

I wouldnt mind knowing this either. I'm currently intending to use Thermaline plus 30mm for my solid wall insulation project as it already has plasterboard attached to the insulation ready for skimming.

Thanks.