QuestionsGarden SkillsTechniquesCompost-makingBriquette ash 0 Vote Up Vote Down Gerry Dornan asked 9 years ago Can I add briquette ash to my compost heap, when it’s cold ! 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 6 years ago Peat ash has no nutrient or soil structural value, but yes, if you wish, to mix and spread it.