Cavity help

[jigpips]

Hi, just wondering if any could point me in the right direction regarding this floor cavity please.

House is somewhere around 1930s, I have a 50-60mm cavity where my joists run through the inner wall, and stop 5-10mm before the outer wall.
There are air bricks on the outer wall, so assuming I cant completely close the cavity?
Just wondering how to maybe insulate and close this off, and then floor board.

Thanks Steve

 

[Ivor Windybottom]

Usually the airbricks are ducted through the cavity into the subfloor crawl space, by fitting duct and new air bricks from the outside...

Then the entire cavity is filled.

As far as I know, the joist ends would just get surrounded by insulation, no special precautions are taken. In theory it allows some air circulation and is moisture repellant.

 

[jigpips]

Thanks.
I'll rebuild the inner wall between the cavity, leaving voids for the air to circulate through to the crawl space.

Then fill the cavity with a insulation.
Thanks again

 

[ree]

OP,
You show a DPC on the outer skin but no DPC on the inner skin which is the important skin ref any damp.
Why has the floor & wall been opened up - was there a problem? Do you intend to keep opening up?
Your skinny floorboards are for cladding not for flooring.
Where the exposed joist tails enter the cavity then saw them off, & slip DPC material under the tails as they sit on the brickwork.
Why not post larger context pics showing the inside wall from the room, & the outside wall from outside?

Ducting air bricks is unnecessary - we have yet to see any existing air bricks.
The "entire cavity is filled" with what? If filled with insulation is meant then how would that work?
"Special precautions" are taken - The correct method for joist ends sitting in a wall is to cap them with DPC material - they certainly dont get surrounded with insulation.
Insulation is not "water repellent".

 

[jigpips]

Hi, the wall was removed to place upvc french doors.

Both inner and outer wall are sat on slate dpc.
The joists sit directly on the slate dpc, there is no way of lifting them to place dpm.

No signs of damp or moisture in the foundation or cavity.
The cavity has some remnants of old mortar at the bottom.

The air bricks are on the outside wall at dpc level.

 

[noseall]

Hi, just wondering if any could point me in the right direction regarding this floor cavity please.

House is somewhere around 1930s, I have a 50-60mm cavity where my joists run through the inner wall, and stop 5-10mm before the outer wall.
There are air bricks on the outer wall, so assuming I cant completely close the cavity?
Just wondering how to maybe insulate and close this off, and then floor board.

Thanks Steve

Broad DPC slipped down the inside face of the outside wall. Foam any gaps. Extend flooring up to new patio door sill. Adjust any floor joist woodwork to suit, prior to adding DPC and foam. Don't block any existing airbricks.

 

[Nige F]

OP,
You show a DPC on the outer skin but no DPC on the inner skin which is the important skin ref any damp.
Why has the floor & wall been opened up - was there a problem? Do you intend to keep opening up?
Your skinny floorboards are

not floorboards but laminate flooring . The floorboard is laying under it.