Ideas for fixing 8cm gap between laminate and wall
If your floors have their seams lined-up like the diagram (very wrong), it looks quite bad already so adding a bunch of scraps on the end won't hurt. The best solution is to literally start over &amp; use as many of the old pieces in the manufacturer's instructions followed new &amp; proper floors...that have at least 3 rows laid as a dry fit so you don't have any pieces shorter than 30cm.

Each row of planks has its butt seams offset from the next row &amp; at least the same for a third row before you repeat. One main reason for this is exactly your situation here. Be careful &amp; conscious with your measurements &amp; cut 1 board at a time...do I leave the line, cut-out the line or split the line.

With varied lengths meeting the wall you can custom cut &amp; even scribe each piece's end for a flawless fit or common very minor manufacturer's gap. Also, any ridges, popped nail heads, splintered subfloor faces, heavy paint or glue deposits, etc. should all be flattened, leveled, sanded, chiseled &amp; removed prior to installing the new floor.