sealing in joists

[pdhendry]

Hello,

renovating my first place.. so probably gonna have a few questions.

the first thing im unsure on is the floor/ceiling joists on the first floor.

its a 1960's cavity wall house, and the joists sit over the over the wall. however there is some pretty big gaps between the joist of the wall, and i can feel the draughts coming through them. is this for ventalation or has the mortar erroded over time? whats the best thing to patch them back up? also notice some black marks which are only present around the end of the joists.. doesnt come away with mould/mildrew cleaner..

 

[foxhole]

Always like that, but it’s not broken, You can’t fix it..

 

[pdhendry]

Can put expanding foam filler in it or something to stop draughts? house is very cold.. so trying to eliminate as much as possible

 

[thomp1983]

Yes you can put expanding foam in the gaps, get yourself a gun instead of using the tins with the nozzle fitted as it's alot more controllable