Des lignes se sont implantees sur mes faces

bonjour apres que j’ai crée mon volume et que je l ai peint, durant l insertion de meubles des lignes se sont crées sur les surface de la maison et les coupées. Si je les efface j’efface aussi une epaisseur du mur

merci de votre aide

It’s hard to tell with so little information what you need to do to fix it. Please share the SKP file or at least some screen shots so we have some hope of giving you a solution.

It seems likely that the walls are being pulled out of plane by the things you are inserting. This may happen if the existing model contents are not groups or components because all “loose” geometry in SketchUp interacts with everything else. As Dave observed, if you can share the skp file, we can look and tell you for certain what is happening.

slbaumgartner your guess seems quite right, I’m loading the file on a sharing site

thank you for your help to both here is the link