Gap between soffit and wall - is it for ventilation??

[this is my username]

Nor that I have sorted out my "plasterboard tent" I need to try and resolve the problem which brought it to light, which is wasps nesting in the roof space above a single-storey extension. The wasps are accessing the space by crawling through the gap between the soffit and the wall (picture below).

Before I fill the gap - can anyone tell me whether the gap might be there for ventilation? There are no vents in the soffits or bargeboards, and no vents that I am aware of in to the roof space. My guess would be that maybe a breathable felt was used when the roof was built, but I have no way of knowing that. There is no access in to the roof space for me to investigate.

Can I just fill up the gap - or might it block ventilation and cause problems in the roof?

[98elise]

I doubt its specially for ventilation, as you can get soffits with ventilation strips built in.

Its a good idea to have the loft space ventilated though to avoid condensation.

[wolfracesonic]

Some clear silicone should seal the gap and keep the wasps out. As said above ventilation won’t hurt so if you can, fit some round soffit vents ones with fly mesh; not a major job, 70mm hole saw and your good to go, just try and avoid where the timbers holding the soffit are!

[OIC]

Filling the gap won't stop wasps if they want to make a nest in the roof space.

They make them out of wood which they chew on loudly in spring to pulp.

Good news is they don't return to old nests, unlike bees.

So I'd just leave the gap as it is.

If you keep an eye out for queens (ooo er) in spring you can encourage any taking a fancy to your house to feck off quite easily, either with death or just by annoying them.

They won't nest in a site where they are going to be disturbed.

[this is my username]

Thanks all.

They may not return to an old nest, but they will happily return to a location where they have nested before - this is the third year they have nested in there, last year they were a bit further along ....

[AdamV12V]

The majority of roofs in the uk are what s called a cold roof which means there must be plenty of ventilation under the tiles/slates and above the insulated ceiling of the upper floor (often called loft insulation).

The gaps on your facias may not actually be the intentional ventilation areas as it s hard to tell from your photo but regardless there should be plenty of ventilation which ultimately means yes, wasps can get in wherever such ventilation points are.

A warm roof is different. The insulation is above the rafters on the underside of the final waterproof layer (ie the tiles etc), then the airspace beneath that is sealed up airtight which acts as a warm air trap, then no insulation on the ceiling used either.