Hi, My guttering has been leaking for a month or so (being fixed soon) and we’ve started noticing a fusty damp smell in sub floor. In the alley way next to our house the base brick has slate running along the bottom of the house. It’s absolutely sodden wet and flaking away. I’m assuming this is a water repellent and as it’s seen excess water from gutter it’s failed. Would i need to replace this slate with new or could i take back to brick and apply bitumen. Note: bricks and slate have been injected as you can see in photo. TIA
