Rising damp - This is more commonly found in older properties and occurs through water from the ground rising through your walls. It will usually rise to the height of one metre high and can often be seen through tide marks on your walls which appear darker and may be damp to touch. Your skirting boards, wallpaper/paint may be damaged and you may be able to smell the damp too. 

Penetrating damp - This damp can be seen on your outside walls and can be due to a number of reasons, including leaking pipes, missing roof tiles, or overflowing guttering. Your walls may be blotchy and have wet patches, you may also notice some mould of fungus. 

Condensation - This is the most common form of damp and is seen more throughout winter when warm air condenses on cool walls. It's more common in rooms that generate a lot of moisture including bathrooms and kitchens and rooms with poor ventilation. Signs of condensation include black spots of mould, damp patches on your walls or puddles of water on window sills/steamed up windows. 

Black Mould - Black mould is caused due to excessive moisture and poor ventilation in your home. Places your most likely to spot mould include internal walls, window sills and on ceiling. You may also notice a musty smell as a result of the mould growth.