Does anyone know the cause of this fluff?

thermal2844

Some kind of critter? I noticed it in a broken air brick.

Ant555

Cavity wall insulation just falling down due to gravity, high winds whistling around or other structural changes?

societys_child

As above, cavity wall insulation, the air brick is usually filled if not needed for ventilation.


Who smashed the air brick? Seal it, before you lose any more.

thermal2844

Oh I see, it just showed up out of the blue so I thought an animal was making a nest. I didn’t realise this could happen due to high winds, it has been stormy.

Previous tenants I assume smashed it, it was rented 10 years before we bought it (fixer upper). One of the many things on the to-do list. It connects to the room with the boiler so I’m assuming it’s needed for venting but then again the boiler itself has a vent, so maybe not?

Mistral001

Air bricks are there to provide a ventilation duct through the wall. The sides of this duct must be lined where it goes through the cavity so that the air does not enter the cavity but is channelled to the void under the floor of the house. This is called closing the cavity at the air vents.

If what we see in the picture is insulation, then clearly the cavity is not closed at the air vent . This is down to faulty construction by the original builder or faulty design.

However, are you sure this is insulation? Usually cavity wall insulation is expanded polystyrene.

thermal2844

Mistral001 wrote: »

Air bricks are there to provide a ventilation duct through the wall. The sides of this duct must be lined where it goes through the cavity so that the air does not enter the cavity but is channelled to the void under the floor of the house. This is called closing the cavity at the air vents.

If what we see in the picture is insulation, then clearly the cavity is not closed at the air vent . This is down to faulty construction by the original builder or faulty design.

However, are you sure this is insulation? Usually cavity wall insulation is expanded polystyrene.

The house was built in the 30’s so not sure what the building practices were or what has been done in the intervening years if this is faulty. I know nothing on this topic so all new to me. I had a search and it looks like wool insulation?

Mistral001

Do you know if the house has cavity walls?

Ruski

@Mistral - this is blown fibre insulation.

HTH

Russ

societys_child

. . and has been installed far more recently than the 1930's.

owen_money

Weevils I believe

societys_child

thermal2844 wrote: »

The house was built in the 30’s so not sure what the building practices were or what has been done in the intervening years if this is faulty. I know nothing on this topic so all new to me. I had a search and it looks like wool insulation?

Is there a corresponding air vent internally? If not, it's pointless, seal the external air brick. If there is open it up and make some kind of tunnel to allow air to pass through, but seal the cavity to prevent loss any more loss of insulation.


Yes it's insulation, blown in years after the house was built.