An easy fix for this window frame?

[SJRSJR]

Hi. Years ago I paid a local 'handyman' to fix the rotting wood base under the double glazing. He charged me for replacing the wood with a new hardwood piece and repainting it. It's rotted again so I thought I'd replace it and started hacking it out. I now realise he couldn't have replaced it as it's one deep piece which it runs through to the internal side and that wasn't disturbed at the time.

Any suggestions as to how I can fix this up without removing the entire piece?

I have a wide strip of UPVC which would cover the gap but don't know what to put behind it Thanks

 

[diy_fun_uk]

You could use something like EverBuild One Strike or equivalent to fill the void, finishing a few mm within the outer edge of the frame. Leave to cure. Cut your upvc strip to size, run a bead of quick grab or silicon inside, offer strip up so it's flush with frame, silicon around outer edge, job done.

 

[daviddave]

Hi,
in alternative you can use a self-expandent strip like this
https://eshop.wuerth.at/Sealing-tap...IX-66-15-30-BLCK-5M/0875066153.sku/en/US/EUR/

 

[SJRSJR]

Thanks for the replies. By the time I read them I'd already gone with Soudal Flexifoam and finished off with the PVC strip. Had once had a bad experience with foam filler but this was low expansion and I used a gun which made all the difference. Hopefully it will do the job.