Condensation problems in an already converted loft

[randersonc]

The loft was already converted when we moved into this property 5 years ago, however in the last two years we have struggling with a damp smell in the loft, and condensation on the walls, under the external wall side eave. This year that turned into black mould.

We have bleached the walls to kill the mould, and treated the walls with an anti damp paint to deal with initial problem. However we need to ventilate the loft properly, and also have no ventiliation in the bathroom which sits at the bottom of the stairs to the loft, so are getting a bathroom fit fitted asap.

First question is what options do we have that are cost effective for ventilating the loft ?

Also does it sound like a ventilation issue- or should we be more concerned about rising damp/the external wall or the roof. We keep being given different opinions.

 

[RedHerring2]

You've posted in the wrong section. I've asked the mods to move it for you.

Be prepared for a long question and answer session 'cos understanding the situation and finding a reasonable solution could take a while.

Firstly, as a DIYer I think you can rule out rising damp. I understand that it rarely rises further than 1 meter from ground level.

There is a possibilty that ventialtion has been reduced during the conversion process and you'll may need to address that. So there may be quite a bit to do.

Others will probably come back for more info' so arm yourself with as much understanding of the construction process during the conversion work.

 

[AronSearle]

Due to the location (wall side eave) I would suspect likely cold bridging due to inadequate or poorly fitted insulation, possibly combined with to much moisture in the air.

 

[freddiemercurystwin]

How old is the house, when was it converted, was it done to Building Regs, what insulation is fitted, is there any ventilation of the room, trickle vents in the windows? Questions questions.

 

[mointainwalker]

Do you know the exact make-up of the wall ? i.e. plasterboard ( with /without foil ) type and thickness of insulation, any voids before outer covering ?

Even if you have any plans these cannot be relied on as , unfortunately, many builders either cheat or regard them as useless and do what they want.