No insulation (and no space for it) = damp

MouldyOldDough

What do you call the roofline of a 1950's semi  - when the roofline on the first floor is such where the ceilings are virtually touching the tiles - on the outside 3 feet of the rooms ?

So the house looks like it has a skirt on it.

We have such a property and damp is now appearing on the ceilings

stuart45

Do you mean a Mansard hipped roof, as on the Cornish PRC homes?

Doozergirl

A picture speaks a thousand words!

GDB2222

If it is 70 years old, or so, the roofing felt may have reached the end of its lifespan?

stuart45

Doozergirl said:

A picture speaks a thousand words!

Here's one of a Cornish PRC with a full length skirt

stuart45

Here's one for the lads. Cornish PRC type 2 with a mini skirt.

MouldyOldDough

@Doozergirl

Its like this - the whole roof structure sits about 2 ft lower than a "normal" roof

leaving a sloping ceiling at the edge of rooms on 1st floor

the felt is fine as are the actual tiles (the roof is NOT leaking - the damp comes from inside)

I understand that clear water is a sign of condensation - whereas brown or yellow staining is a sign of a leak

We've got stacks of insulation in the main roof - just not at the edges because there's no space for it

stuart45

That's known as a collar roof. It common to get condensation there, as there's often no insulation. Best to use something like Kingspan.

MouldyOldDough

stuart45 said:

That's known as a collar roof. It common to get condensation there, as there's often no insulation. Best to use something like Kingspan.

I don't believe that there is even a big enough gap to get a board in there - when viewed from above, it looks as if it is tight up against the rafters.

Also - it appears that a collar roof only works when the span is less than 4 metres - ours is double that - 8 metres !!

(the full house width)

ThisIsWeird

I guess line the inside with insulated plasterboard? It'll also be more effective than insulation added to the other side.

Mitre the board edges to fit nicely against the wall and upper ceiling. Jobbie should be jobbed?

Photo of the inside, MOD?

in_my_wellies

My house has this sort of roof. The blurb called it 'galleried ceilings', it's 1908.
When we moved in in 1883 the ceilings were black with mould in 4 of the bedrooms, mostly behind 1950's style hardboard built-in wardrobes. 
We striped out the wardrobes and installed an airbrick in each bedroom and the problem has never returned even in the rooms which are largely unheated. I thought the airbricks would be drafty but TBH I don't even notice them now