Loft Insulation help

[Rich T]

We have recently moved into a 1960's semi detached house and it has condensation issues in the upstairs bedrooms. The plaster around the windows is cracking and bulging from the damp soaking through them.

Looking in the loft I see that the previous owners have had insulation and boarding fitted and the insulation is pushed right into the eaves, I would think that this is wrong and the main cause of our issues but im no expert. They also have polystyrene wedges pushed into felt under the roof and a note was stapled to the roof saying not to remove them.

Looking outside the house under the eaves I see that there are no vents of the soffits where our neighbour on the other side of the semi has them. Essentially the space between soffits and the loft is completely blocked off.

Has the installer got this all wrong or have they done it right?
I've added some photos of the insulation, the work sheet they left & the damp soaking through above the windows.

Any help greatly appreciated.

 

[KenGMac]

Rich T, good evening.

First post in here? welcome.

OK any highly insulated attic must have a full cross flow of ventilation, by stuffing the insulation into the eaves any possibility of venting has [for a long time] not been on-going..

One way around this will be to simply rip out the insulation that was stuffed into the eaves, if when you do that? there is an appreciable air flow then job done. If when you remove the above? if you see daylight in several places, that may well be enough to get an air flow going? if not have a look at installing "Circular Soffit vents"

As an aside? do the external walls have an old type of cavity fill?

Ken.

 

[Rich T]

Yes first post, although browsing for a while now

I have today pealed back some of the insulation and it seems as though there's was an improved draft through into the loft. I could see cobwebs blowing around in the breeze.

I also uncovered a nest formed in the insulation! My guess birds but there was no extra material brought in like twigs just dirt and bits of eaten food. There must be some ventilation if birds can get in.

I do believe the house has at some point had polystyrene beads blown into the cavity from above. Found this out when we had the windows changed and it was dropping out but there wasn't much of it ado suspect it was done quite some time ago.

 

[oldbutnotdead]

I'd be surprised if the window damp was being caused by the loft insulation. Is the damp all round the windows or just at the top? Given that the damp appears to be coming from the outside to the inside I'd be more suspicious of poorly fitted double glazing units or knackered gutters or that sort of thing.

 

[Rich T]

The damp is just above the windows the sides and bottom seem fine.

Windows have been in a while now but every time we get a cold spell we get this damp coming through the plaster so much so that there are drops of water all along the plaster.

 

[foxhole]

What ventilation do you have in the rooms?

 

[Rich T]

Just the opening windows with windows that lock slightly open in the upstairs rooms.

Downstairs rooms have suspended timber floors with air bricks under.

 

[KenGMac]

Rich T, good evening again.

OK loft insulation out of the way, in a stiff breeze there will be an air flow, did you see any daylight at the eaves? there is generally some daylight seen internally if possible have a look on a bright sunny day?

As for bird entry, they can get in through a very small gap when needed, the entry point [if birds] would tend to be very close to the "Nest" you located. as an aside, were there any droppings? if so what shape?

Back to the dampness above the window, how many windows affected? and do they all face in one direction? if so it may be a "Cold Bridge" caused by the concrete "boot lintel" ?

ken.

 

[Rich T]

Hi Ken,

No there's no daylight to be seen, the roof pitch and edge of the ceilings are so close its impossible to see down into the eaves. I have an inspection camera that I could poke down there for a look but I doubt I would see much as the focus is quite short.

No droppings in the nest just lots of dust and water marks on the plasterboard. Also husks of whatever they have been eating.

The damp is on three of the four upstairs widows, only one seems fine. Two windows on each side of the house. The sun rises on the back two windows and sets on the front two widows.

How would I know if they're was a boot lintel? Not a term I've heard of before.