Removing lines in top layer

[linda_salihu]

Hi everyone, 

Can someone help me. 

How can I remove these lines on the top of my building please without just dragging the slab up.

Thanks, 

Linda

[RC_RVT]

You can attach the wall using the "Attach Top/Base" option.

When you select the walls, click "Attach Top/Base", then click the floor you want to attach them to.

[azad.Nanva]

@linda_salihu 

this is curtain wall in roof or floor , you can not removing them you can hide them by select one by one but this wrong, you should change the height of your curtain wall by Attach or changing the Height.