Patio Door Frame Rotten

[Martyn Bell]

I have a UPVC double glazed patio door which for some strange reason has wood underneath the frame. The wood has rotten away & I have removed it, supporting the window temporarily on small blocks of wood. It has been suggested that I should replace the wood with plastic, but where can I purchase plastic? Could I use cement to fill the gap, it's only about an inch or so. If so what kind on mix will work best?

 

[Gazman16]

Several possibility's. Could you post a few pics so we can determine the best one

 

[Martyn Bell]

Thank you Gazman 16 sorry for my slow reply, found your reply in my junk mail. When I removed the rotten wood it damaged a cement fillet directly above the damp proof course. I have removed the cement which leaves enough space to fit driveway blocks, so this is what I have done. Cemented the blocks in place & refitted a trim that came off. Hope this is a suitable repair. Please let me know if this is wrong.