How to fill joins between plasterboard sheets

[TheMeisterT]

Hi guys,

This is my first post

I’ve got a single brick outhouse off the back of my kitchen which has always been cold and damp and pretty unusable.

This weekend I had a builder come round and insulate it, by fitting a studwork frame to all the interior walls, filling the frame with loft insulation and then boarding over with plasterboard sheets. To save money I told him not to bother plastering over the top or painting it as it’s only going to be used for storage.

It looks great, but I have now decided I would like to decorate it myself and am wondering the best way to fill the joins where each of the boards meet. Should I use Polyfill or is there something more suitable?

Secondly, once the gaps are filled, can I paint directly onto the boards, or do I need to use a primer/undercoat first?

Many thanks!

 

[kjacko]

Are they tapered edge boards? If so, you can just use easyfill to fill the valley the taper creates. A light sanding when dry and its ready to paint.
If they aren't tapered edges, it might be better to scrim tape the joints then either easyfill it, but you'd need to feather it out quite a way to avoid seeing the rise, or plaster skim the whole wall.