Glass wool around drain pipes in a multi-storey building

[mfripp]

Our flat is in a multi-storey building, with other flats above and below. The building has a common drain pipe that runs vertically through all the flats, in one corner of the kitchen. This pipe is grey plastic, about 10cm in diameter, and sits about 3 cm from the wall. In our flat, they have wrapped this pipe in fibreglass batts (glass wool, like insulation for new houses) and built a 30cm x 30cm enclosure around it.

We are redoing the kitchen and would like to reduce the size of this enclosure and claim back a little space. I'm trying to figure out how much extra space we could get. That depends in part on whether we need to leave the fiberglass in place.

Does anyone know why this drain pipe would be wrapped in fibreglass insulation, and whether we could remove it or compress it so it takes up less space? My best guess is that it is there to absorb the sound of water running through the pipe, but I'd be interested in other ideas.

 

[mrgas]

Probably just for sound insulation.
Maybe an element of fire protection also!

 

[JohnD]

Also for draughts, smells and smoke. Otherwise air from downstairs kitchen will get into yours..

 

[Biggles..]

Pipe will be sealed between floors with a fire collar,that boxing will be fire board normally 30minutes, the lagging will be for sound and fire.

The problem is that box as it has a pipe that serves all flats will have been subject to labc and nhbc checks,alteration to it may cause problems with any gusrentees or certificates isiued for your flat should anything untoward happen.

Leave it where it is and work round it it not that big.

 

[mfripp]

Pipe will be sealed between floors with a fire collar,that boxing will be fire board normally 30minutes

Thanks very much for these comments. As it is, we are removing a rectangular section of false wall/ceiling that intersects this pipe box horizontally. So we need to replace a 40x20 cm piece of drywall on the upper part of the soil pipe box, where the old hollow wall/ceiling section used to attach. I don't want to compromise on fire safety, so I want to make sure I patch it with the same type of drywall as the rest of the soil pipe box.

Is there any way to tell by inspection of the edge of the existing drywall, whether it is fire board or standard drywall?

The building has concrete floors between structures and I haven't noticed a fire collar around the soil pipe, but I could open up the box again and take a look. Maybe they don't need as much fire protection in concrete structures?