Builders sand in PVA before skim

[Terry lambert]

A plasterer told me you would get a better finish and adhesion on old Walls if you mixed builders sand into PVA and then coat the wall.

Also helps you to gauge thickness and avoid thin spots.

Is he talking twaddle?

 

[Micilin]

Yes and no.

The sand will provide a key when the PVA is dry when applied a day before plastering.Cheaper than Bondit if done properly!

But for thickness and thin spots,no.
If the wall is flat, then a 2mm coat is specified by the manufacturer. Sand won't help this. likewise if it needs it a bit thicker somewhere, sand won't help either. This is down to the plasterer's technique. Indeed, if you have a high spot on the wall where you want the finish a bit tighter, then the Sand may grin through.

Remember the thinnest coat possible to leave a good finish is better. Bulking up with sand merely to put on more than 2 mm just for the sake of it is not a good idea. If your wall needs filing out, use bonding .