I have stripped the old vines (20 year) off the house and they left little suckers /dots all over. I know I will have to repaint, but the little suckers are more than just visual, pieces of the plant are still hanging on even after scraping. will a pressure washer take them off? Or what will?

Keep scraping... 

1 hour ago, gingerandtabby said:

but the little suckers are more than just visual, pieces of the plant

Hmmmm so what are they?

Try an oxy-acetylene torch ( not recommended for weatherboards ).

Meh. paint over them.

For speed, instead of hand scraper use a wire-brush attachment and a small grinder. One very light, light touch will scour them off the walls.

 

Don't paint over them without removing the bulk of the sucker/claw because as they rot (and they will) they will disintegrate and the paint you slap over them will more than likely be compromised.

These suckers, feet, 'adapted stems' actually, are so powerful they, at magnified levels, dig right into stone, Gyprock, clay brick, cinder or Besa blocks.

Ivy, Wisteria, and Ipomia or 'Morning Glory' vine will do this.

The suckering and probing types like Ivy will break the walls apart via the chemical excretions from their many thousands of 'feet'.

 

If you get rid of the small visible lumps and bumps left behind, then seal the walls then paint with quality exterior paint it will last you for years.

 

If anyone wants to grow vines around the house make sure you chose NON- aggressive non-invasive species that don't sucker or use probing tendrils e.g. Chinese Jasmine (white star-like fragrant flower) is a good example.

This Jasmine is a relatively tame climber, a beautiful plant for LOS.

Chinese Jasmine allows for shaping, pruning, and during the major growing period before good coverage is achieved is easily redirecting the growth tips to cover a frame or up posts or even to shape into whatever your fancy takes.

Of course even Jasmine will spread if left and not managed.
 

Always best to erect a stand alone frame away from the building and cover with a galvanised 'dog' wire and grow on this. A space of 200mm between wall and the back of the frame is usually sufficient for safe growing. 

Edited August 15, 20233 yr by Tropposurfer

troppersurfer, Thanks for good advice. Also get rid of it with fire is good. Thanks both.