Hey, thanks, is that this stuff?
https://www.toolstation.com/thistle-undercoat-plaster/p73927?store=NA&utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&gclid=CjwKCAjwm7mEBhBsEiwA_of-TAJMo4BX1ifyOYW8sSMAIyaVQRB5Suj_Pbx67f32uGw-xFAsxzamdRoCvGgQAvD_BwE