There are several causes for damp patches appearing on interior walls including damaged guttering, cracked roof tiles and more commonly condensation. Condensation forms when warm moist air within a room touches a cold internal wall or surface.
Damp patches are caused when moisture is able to accumulate below the surface in materials throughout your home. The most common cause of this type of damp is condensation, although leaks in pipes or gaps in your roof can also cause moisture to soak into walls and ceilings.
most likely, the walls are wicking water up from the ground. Check your downspouts to make sure all water is being pushed far away from the house. Is the ground properly sloping away from the house? Is the back ``garden''/patio sloping away from the house?
most likely, the walls are wicking water up from the ground. Check your downspouts to make sure all water is being pushed far away from the house. Is the ground properly sloping away from the house? Is the back ``garden''/patio sloping away from the house?
Over time, bricks can crack, and mortar can erode, creating pathways for water to enter. Pay special attention to any visible cracks, gaps, or crumbling mortar. Gutter and Downspout Inspection: Faulty gutters and downspouts can direct water towards the wall instead of away from the property.
Some damp is caused by condensation. Condensation is perhaps the most common form of dampness that can appear in your property. It can cause wallpaper to peel, damp patches to appear on walls and a build up of moisture on your windows.
Moisture and water that get behind the wall cause the backside of the drywall to soften and even become mushy. Look for soft spots or wet spots in the drywall and gently press into them. If the drywall depresses, there is most likely water damage. Mold on your walls' surfaces.
You can generally identify rising damp by the damage it causes to the internal walls. Rising Damp creates noticeable tide marks that usually appear around halfway up the wall. In addition, as the moisture absorbed from the internal brickwork travels up it can cause wallpaper and plaster to start cracking or peeling.
The general rule is that any moisture reading over 16% is considered damp and needs attention. If your reading is over 20%, you may need to replace the drywall entirely. The walls in your home with healthy humidity levels should have a moisture reading between 12 to 15%.
The misdiagnosis of rising damp
Rising damp is a complex hazard to identify and is often confused with other forms of damp, particularly condensation.
Step 1: Look for Visible Signs of Water Damage
Some common signs include wet walls, wet spots on floors or ceilings, peeling or bubbling paint or wallpaper, sagging walls or ceilings, discolored patches on walls or ceilings, and a musty smell.
There is no clearer sign of damp than actual discolouration of your walls, ceilings or floors. Whether it's the mark of the damp itself or yellow or brown discolouration, you're bound to spot this sign of damp in your property as it can ruin the look of any property.
There are a number of factors that can cause damp including penetrating damp where water from outside gets into the brickwork through gaps and cracks. If the patches are clustered around windows and doors, then it's likely that rain is getting in through gaps around the frames.
It is not something that will go away on its own so if you notice a smell of damp in your home, it is important to take the necessary steps to get rid of it.
One of the main structural issues related to damp is known as rising damp. This can happen when the damp proof course in your outer wall fails, which allows moisture to travel up through the inner cavity wall. This might be first seen as isolated patches if it has damaged your cavity wall ties.
Dehumidifiers can indeed aid in drying wet walls. After a flood, leak, or a spell of extreme humidity, damp walls can develop. A dehumidifier removes extra moisture from the air, lowers the humidity, and stimulates evaporation.
Rising dampness is the priciest issue to fix, and it occurs when dampness rises up your walls through capillary action, often causing extensive damage to paint and plaster. It can also cause structural issues and weaken your walls, which is why it costs more than the other two types to fix.
The areas where the moisture can evaporate is where the damage is the most visible with the salts damaging the plaster and masonry. Damp patches on walls – stains that may be brownish to light yellowish in colour.
Unfortunately, you can't just paint over damp or mould in the hope it will disappear. Even if you use waterproof paint, it can still seep through over time. Depending on how bad the problem is, you may be able to remove the mould by cleaning the area without repainting.
Use fans to move air around the damp walls. Dehumidifiers can help remove moisture from the air, which indirectly removes it from the walls, too. To speed up evaporation, remove molding and baseboards to prevent moisture from entering behind them. Store the molding in a dry, safe place to avoid damaging it.
Tape a square of aluminium foil to the wall and leave it there for a day. On inspection, if the side facing away from the wall is wet, you have an issue with condensation. If the inside of the foil is wet, you have penetrating or rising damp.