Sewing help - can I turn curtains 90deg..?

[Mij]

Moved from house with windows taller than wide, to one with windows wider than tall in the DDs' bedroom. I'm just about ok altering stuff on the sewing machine (assuming I can find the power lead) but is there anything special about curtain construction that would mean I couldn't take the tape off the top, turn through 90deg and sew new (longer) tape across the side, to make it the new top..? They're almost the perfect size like that and we all really like the fabric

Thanks

Are they lined?

I'd remove the tape them wash before reattaching new tape

How does the pattern lie?

Yes they're lined. Pattern is just rows of very big coloured dots so I don't think there's a directional issue. Will the lining be attached under the old tape do you think?

How many sides are the linings joined on? If it's 3 or 4 you will have to change it - if it's one then it will be easier

Are they seamed down the middle?

Should be ok to do that I do as katymac said remove tape and wash and iron the curtains itll make it easier to reattach the tape. If they are lined youll need to either remove it or sew it to what was the bottom edge of the curtains or itll flop and hang wonky

I'm going to have to look at them in more detail! They're not joined, they were ready-mades from John Lewis, with blackout lining. I'm thinking if I tack or pin the lining before removing the tape then everything will stay put until I can sew the lining, and then put the tape on..?

The bottom edge of the tape will be holding the lining in so when you take the tape off, yes it will be free. When you turn it sideways you will now have the top and bottom where the lining is sewn to main fabric, you could leave this but will have to do something which is now the sides.

You can do it easily by folding over the side 1" twice and sewing through...the edge that was the hem you may have to unpick and do the same.

A neater way would be to turn it inside out and hem the sides but you would have to undo the now bottom or top to do this