Applying matt emulsion over soft sheen

[Deansplit]

Hi

Do I need to prime or lightly key a soft sheen wall if applying matt emulsion over it? It's the Valspar V700 matt which says it's a paint and primer in one so assume it'll go on fine. 110sq m of hall and landing to redo so could well do without any prep!!

Thanks

 

[footprints]

Have a quick google for "Valspar paint smell of cat urine" before you do check if your batch might be affected
As a rule matt over matt is OK, vinyl silk over matt is OK matt over vinyl silk is the main problem one. Users are often advised to paint with soft sheen as an intermediate coat before painting matt over vinyl silk so you should be OK.
Still a good idea to wash down and give it a light rub I would think, maybe do a test area before committing to the whole lot!

 

[misterhelpful]

Combined paint & primers are popular over here and generally tend to adhere to anything but, with it being the UK version of Valspar that you are using (it's really not the same as it's US version), I would recommend a light sanding with 180 grit just to give a key and remember to dust off.