Hole in single-skin party wall

[Iyaman2024]

Good evening,

I would like some advice or suggestions on how to seal these holes along the party wall.

This picture is taken from inside my loft. Behind this wall is a chimney that has been built into the party wall.
It has been dropped but has not been slate/tiled (long story). It's open except for a piece of felt. However, there is an unbearable stench that comes through especially on a windy day. If the neighbour has been smoking lots of weed/cigarettes, I get that too. I also get the cooking smell.

I need a girl-friendly DIY solution, please.

 

[Harry Bloomfield]

I need a girl-friendly DIY solution, please.

Mortared in bricks, to fully fill the hole, is the proper solution. A quick temporary fix, might be a bit of plasterboard,fully sealed in place with fire retardant expanding foam.

 

[Iyaman2024]

Hello Harry! Thanks so much for your help.

Would marine ply be better? I will also have to get someone to do a jigsaw cut around the floor joists and rafters?
Also, which foam has got the adhesive? Could you please recommend one?

Thanks
T

 

[Harry Bloomfield]

Would marine ply be better? I will also have to get someone to do a jigsaw cut around the floor joists and rafters?

If you need to get someone in, better to get someone in with bricks and mortar, to fill the hole properly.

 

[Iyaman2024]

Thank you!

 

[Justin Passing]

Temporary fix:
a heavy duty dustbin liner (maybe doubled)or fairly flexible rubble bag and a big can or two of fireproof expanding foam. Push the closed end of the rubble bag into the hole, and expand it out best you can so it fills the hole. You could blow into the bag (big lungs or a hoover on blow)
Tie a cord round the plastic bag near as you can get to the hole.
Insert nozzle from foam can, through the tied neck of the bag - it has to let the air and excess foam out. Fill the bag with foam.
Remove can, tie knot tight.
The foam expands a lot (more if you let it out of the can faster) and pushes the bag into the cracks. It will fill the hole, but not be too bad to remove, because it isn't adhering - the bag's between it and the masonry.
Have "fixed" a hole in a neighbour's roof like that where a couple of tiles had blown off, at 2 a.m. . It was gratifyingly successful, given the circumstances