condensation on ceilings after insulation fitted in roof

[arisingquestions]

I accepted a grant for newer insulation in my roof a couple of years ago. It was installed by the company concerned very rapidly. They did not remove the original insulation but put the new insulation over the top.They have contracts to put in roof insulation across the West. I know others who suffer with the same problems. There might be a lot of us. I thought I was doing a 'good thing'.

Since then, in the winters, I have had appalling mould and wet areas where the ceilings meet the external walls below. At first the company said it was due to the 'severity' of the winter ( 2 years ago)...but it happened again last winter and is already happening now, in late Autumn / early winter.

A surveyor from the company came 2 years ago and said that not enough 'wedges' had been fitted where the insulation meets the roof / not enough space for air to leave / circulate....More wedges were put in. The problem did not resolve - if anything it became worse.

The company painted a special mould resistant paint around the top of all the internal walls affected. The mould still came through.My ceilings are wrecked and will need total redecoration once I can resolve the problem.

I have been given conflicting advice by specialists; can anyone shed light please.

(My house is probably about 30 - 40 years old - a modern 'link' 2 bed. The walls were cavity insulated just after building was completed at the request of the tenants.
I have lived here for 16 years.The roof had insulation previously and I never had any problem until the new, thicker, more eco friendly insulation was fitted. I don't dry clothes in the house; no drier, open window whilst cooking. Have double glazing and new eco boiler ) SO ADVICE I HAVE BEEN GIVEN IS:

1)make sure insulation goes right up to edges / into all corners in roof; tuck it in well; don't allow any air in or out (?)
2) put more 'wedges' in at edges to allow more air flow
3) have airbricks put into wall of house below roof area as current 'flashing' does not allow enough air flow
4) have air tiles put into roof

I really don't know which way to turn or how to get advice but i need to act before long term serious damage occurs.

Should I involve an independent surveyor ?
Should I ask a 'roofer' ?
Who fits air bricks if those are what I need ?
Who could I trust to know how to solve this condensation in the roof area problem ?

Many thanks in advance for any advice.

 

[freddiemercurystwin]

1)make sure insulation goes right up to edges / into all corners in roof; tuck it in well; don't allow any air in or out (?)

Whoa Whoa Whoa! Stop right there, get yourself up into the loft and make sure there's a good couple of inches clear airflow from the eaves vents into the roof void.

this is what you need to achieve

If you don't have eaves vents you need to get them installed.

 

[KenGMac]

As Freddies twin has posted,

Imperative that there is an airflow "Above the Insulation"

What happens is that the heat is retained within the rooms of the house, fine, But. Moisture which is present in a huge abundance within the house, especially kitchens and Bathrooms, can and does "Percolate" into the loft space above the Insulation.

Guess what above the Insulation it is actually relatively very cold, Condensation then occurs if there is no adequate through draft of ventilation from the eaves, as per the sketch.

If there is no ventilation, condensation WILL OCCUR the resultant water will run down the underside of the roof felt, and, drip onto the perimeter of the ceilings near the outside walls.

I am in despair of so called "energy Efficiency installers" OK it is a government grant. But the adverts for people to sell the products say " No experience needed, on the Job training.

At what cost, a badly installed roof insulation job can cause near, or actual destruction of a roof inside a few years?