Mortar around UPVC window falling out

[vinny164]

Hi
Looking for some advice on how best approach repairing external pointing / seal around front window.
It looks like previous owners have attempted a mixture of foam, weak / crumbly mortar and silicon and nothing at the top. Some areas around has foam behind thin layer of mortar, other there appears to be a cavity. Inside the window seems to be fine and dry.

My concern is that with just replacing with mortar again is that expansion / contraction may mean mortar just falls out. But using all silicon will look messy.

Appreciate some suggestions on how best to repair. Thanks in advance.

 

[Gazman16]

Personally I would re-cement and then silicone once it has set.
PVC trims and silicone would be the quicker and easier option though

 

[vinny164]

Thanks. Any thoughts of cement / sand mix ratio?
I was tempted to use some pre-mix but the time I previously used pre-mix it was a darker grey colour.

 

[Gazman16]

I would probably just go for yellow sand and cement (grey when gone off) maybe a little yellow mortar dye in it.
I would probably get slated by the builders but I always go for a 3/1 mix.

If you want tips for a really good match/mix you may be better off asking on the builder forum but its such a small amount and you have a few colours there anyway as long as its troweled up neat it will look good.
Personally I masking tape a straight edge (brick and window) for nice straight edges.