Soffit vents / freezing cold

[UHAP023]

Dear All, In a late 50's semi with rooms built into the loft, we have had the original wooden soffit boards replaced with PVC ones. These soffit boards have several of those circular soffit vents, installed on the 3 exposed sides of the house. Since this work was done the house, particularly the floors of the rooms in the loft seem much colder when there is a cold northerly wind blowing.

As I understand it, those soffit vents are needed to provide ventilation for the loft space and are used because the PVC is not breathable like the original wood. However there is hardly any loft space left over from the loft conversion -- just enough for the water header tanks etc.

This seems like a criminal waste of (ever more expensive) energy. So what are my options?

TIA. Tom Crane.

[Alex]

Do not block these vents,they are not there due to upvc they are for the prevention of condensation on the roof felt,

I had to deal with the consequences of this condensation build up in many properties last year due too the cold snaps we did have and it can cause quite a mess and in the extreme severe wood rot.

Alex

[The Natural Philosopher]

Block em up and don't tell the BCO.

My carpenters reckoned the best compromise was to shove rockwool insulation down. They will still breathe but the flow rate will be well down.

[The Natural Philosopher]

yeah but the regulations are way over specified, especially if you have a waterproof roof, and vapour barriers in the ceiling.

Actually one thing I did that really helped was to board out the loft..that stopped air blowing into the insulation.

[Alex]

the vents are not just to ventilate there loft space but the area between the roof felt and the plasterboard/insulation it may be that no insulation was used so investigate that first,how old is the loft conversion.