Flying sparks cause problems if the tent fabric gets holes everywhere. The tent fabric needs to be intact to be the shelter and cosy home the tent is supposed to be. To avoid damages from flying sparks is to avoid flying sparks at all.
Flying sparks come from a small explosion of gases when soft wood, for instance spruce, is burning.
To avoid the damages of flying sparks – use dry hard wood as birch, hickory, ash and dogwood when making an open fire in the Nordic tipi.
Always make the fire small without flames. Watch over it and enjoy your cosy home from home.