Only the ones needed to follow the pipes. Conveniently when the previous owners did the extension, they cut boards, so it will be a stretch long ways and then the smaller cut sections across (a bunch were never actually screwed back down properly anyway). If I need to cut any more I can work that out. Will need to replace 2 lengths of board and the chipboard they put down over the 'hearth' as it is not thick enough, otherwise should be ok.
Only the ones needed to follow the pipes. Conveniently when the previous owners did the extension, they cut boards, so it will be a stretch long ways and then the smaller cut sections across (a bunch were never actually screwed back down properly anyway). If I need to cut any more I can work that out. Will need to replace 2 lengths of board and the chipboard they put down over the 'hearth' as it is not thick enough, otherwise should be ok.