mortar mix around windows

[james19000]

I've taken to renovating my sash windows and having removed the paint from the casing and the loose mortar, I would like to know what ratio of cement to sharp sand I should use.

From the photo's you'll see that its quite a large gap in between the casing and the bricks, up to 1 1/2" in places.

Would it be appropriate to fill this with more foam, similar to what has already there. Alternatively I was thinking of putting in some rolled up chicken wire, something for the mortar to latch on to.

Where the outer cill meets the stone. Would it also be appropriate to put mortar here, or would a silicon filler surfice?

Thank you for your help.

Whilst pulling out the loose mortar, there were loads of newspapers stuck in there. dating back to 1983... Coincidently the year I left school!!!

 

[Doggit]

4:1, slightly dryish so it doesn't slump, and you should get away without the chicken wire. More foam would weaken the fillet, so although it would improve the thermal break, it may cause it's own problems, but it would help to put some on the RH side (last picture.

 

[james19000]

deleted

 

[james19000]

4:1, slightly dryish so it doesn't slump, and you should get away without the chicken wire. More foam would weaken the fillet, so although it would improve the thermal break, it may cause it's own problems, but it would help to put some on the RH side (last picture.

but what ratio

1 cement, 2 sharp sand + 2 plasterers sand + Plastiser?

 

[Doggit]

Sorry, personally, I'd use 1 cement to 4 sharp sand, but I see no reason againts your mix either, but builders sand would be fine rather than plasterers sand which has been washed to take the salts out..