Filling large gap around window frame Fillers, sealants and adhesives for all types of DIY work. Help, advice and information on all aspects of this subject

[TonyB13]

Hello, what's the best way to fill a big gap around the top of a window frame - about 1cm wide by 2cm deep by 40cm long? Different places have different suggestions: decorators caulk, stuff newspaper in then fill over that, use backer rod. Any guidance much appreciated. Thanks.

[stoneyboy]

Hi tonyb13,
Suggest you use expanding foam, once it’s set trim it back and plaster over it.
Regards S