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How to seal windows around blockwork?

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How to seal windows around blockwork?

As the title suggested, I'm looking to get a sort of sealer to seal the window frame around my Blockwork. What's your recommendation on this? And before I apply the sealer on, do I need to scrape off the old sealer around the window frame?


Screen Shot 2023-08-13 at 10.34.38 PM.pngScreen Shot 2023-08-13 at 10.34.44 PM.png

Bunnings Team Member
Bunnings Team Member

Re: How To Seal Windows Around Blockwork

Hi @mike1360,


I'd recommend you use Sikaflex 11FC, which is a flexible polyurethane filler designed for applications like this. It appears the old sealant has shrunk, providing adequate room for the new sealant, so I don't believe removing the old sealant is necessary. Of course, you could do so if any loose sections are easily removable. 


I can't quite tell, but from the image, it looks like quite a large gap. You can prevent excess use of the filler by first packing the gap with filler rod. Push the rod into the gap so there is a 10mm gap between the rod and the front of the window frame. Fill this gap with the Sikaflex and smooth it off with a finger dipped in soapy water so the coved filler reaches from the blockwork to the window frame.


Please let me know if you have any questions.




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