Holes At Level Of First Floor Joists In Bay Window....very Cold And Draughty

[Mosaic]

Here's a thing now. I know enough not to block up airbricks, but these aren't airbricks. These are holes, plain n simple. I've never got up close enough to see if Jerry, the original builder of this house, put any kind of metal grille into them, but judging by the size of the spideys that get in I'm guessing not.
I have four of these holes in a bay window. I've had a good snoop and in some of the neighbour's houses they're blocked up, others not.
What are they for?
Can I safely stuff them up with builder's foam?

[shoota]

If you live in a medieval castle they are probably the holes from out of which the scaffolding grew during its construction.

[1581960]

Could they be necessary vents for gas appliances?

[The Builder]

How big are they, Mose?

In the brickwork?

Where exactly?

[Mosaic]

Nay shoota, them's not putlog holes...

I'm wondering 158 whether they relate to the coal fires used in the property pre-1960s

Builder, they are between the lead flashing of the ground floor and the floorboard level of the first floor, about four in all. Each lies at the mid-point of a window light. About 5cm x 3 cm but I've not got up and measured.

[The Builder]

In that case, Moses, I would guess they are ventilation holes for the floor void between the ground floor ceiling and the first floor.

It's not usually done. In this case I imagine the builder had his own way of doing things.

[Mosaic]

So, to keep out the westerley winds that blow so hard into them that the house is musical, ought I stuff them with builders foam?

[The Builder]

How old is the house, Moses?

[shoota]

Put a log in them?

[Mosaic]

House deeds show it was constructed in 1949, so as soon as the post-war restrictions were lifted. Land cost peanuts round here then and this builder was like so many fellows who had a small business and knocked a few houses.These are basically a 2-up 2-down terraced house, but he built them in twos and called them semis. I like the house cos we've extended it and made it as we want, but this is one of a few things that have bugged me over the years.

[The Builder]

So it's probably cavity construction as well. Could simply be cavity ventilation.

If you ever get a chance to poke something in there, it would be interesting to know if the holes go right through to the floor void, or are simply in the cavity.

Either way... cavities and upstairs floor voids are not ventilated any more. The practice was discontinued many years ago. In fact, the main reason for the change of thinking was for fire spread reasons.

Any fire would be accelerated by the small size of the vents. Just like hanging a newspaper over an open fire to make it draw.

First floor voids really don't need vents since the house is likely to be at an even(ish) temperature across the whole house these days. Condensation is not so much of a problem then.

Bung them up :o)

[Mosaic]

Bunging on its way. Thanks to everyone for taking part.
Shoota - put yer own logs in em. Cheek.

[The Builder]

I think Mose should have BA for knowing what a putlog is ;o)