My wedi niche is not the size I need, can I modify the height and width?
Cutting flanges off wedi niches and combining them to create a larger niche would be the easiest and most reliable option if you wanted to enlarge a niche vertically. The two niches have to be sealed together and reinforced using wedi joint sealant. Additionally, if you want to extend horizontally if there is a stud in the wall where the niche is being installed, combining two wedi niches where the flange goes over the stud creating a vertical separation can also be implemented as well.
Reducing niche openings can also be done by inserting/ gluing a bottom and top strip of two wedi 1/2“ pieces ( laminated to a 1“ piece).
These spacers are set back 1/2“ from the front face of the niche. Another ½“ wedi panel piece needs to be attached as front cover over the spacers.