Many Victorian and pre WW2 houses had blue brick or hard red engineering bricks for a damp course. Look for 2 courses of blues or reds that look denser than commons. If so, check that they are not bridged by soil anywhere, air bricks should be below or in the DPC.
A damp proof course, in the brick veneer example shown below, has two purposes: It prevents moisture from the ground rising up through the external brick skin. (This moisture can cause effervescence which stains the brickwork)
Some older buildings do not have damp proof courses installed during building. Older buildings (built before the 1940s) used lime mortar to prevent moisture from entering the home. These older buildings also had nice, thick walls to stop moisture being an issue. However, all this means, is that damp may still enter the building.
This involves removing sections of the brickwork to add the new damp proof course. You then replace the bricks and mortar and move onto the next section. This isn’t a job for someone without experience. You will need to hire a professional for this type of job and it can be quite expensive. Thankfully there are other methods to repair a DPC.
The location of a damp-proof course or flashing serving as a damp-proof course, must be not less than— 75 mm above the finished surface level of adjacent paved, concreted or landscaped areas that slope away from the wall; or
You can find your DPC by taking a look at the external wall. Look down at ground level and look up about 6 inches or so up the wall. Somewhere around here you will see a thin black line of either slate or plastic running horizontally across the brick work. This is your DPC.
Signs That You Need a Damp-Proof Course Black spot mould forming on interior walls. This is a common sign also of a condensation problem. Watermarks on walls formed by either rising damp or penetrating damp. Plaster peeling off walls and damage to other decorative finishes such as wallpaper.
Damp and Musty Smell One of the easiest damp signs to spot is through the distinct smell of damp within the property. Even if you cannot see damp in your property you will often be able to smell it. Damp often has a distinct smell which is often described as an unpleasant, musky and moist smell.
Damp proof course (DPC) is a barrier of impervious material built into a wall or pier to prevent moisture form moving to any part of the building. The DPC is built into base wall brickwork. It bridges brick skins and/or the brick and pier.
The DPC should be of 40mm thickness and should be of uniform thickness. It should not be provided at the locations of the door openings. The top level of DPC should match with the planned finished floor level.
The damp proof course may be horizontal or vertical. A DPC layer is usually laid below all masonry walls, regardless if the wall is a load bearing wall or a partition wall. A damp-proof membrane (DPM) is a membrane material applied to prevent moisture transmission.
If you are buying a new house and you suspect damp, you'll need to arrange for a HomeBuyers Report (level 2) or Building Survey (level 3). Both these surveys include tests for damp in the walls. A full Building Survey will also look at the condition of the existing damp proofing.
One of the most common signs of condensation is black mould which can occur on any walls of the property. This compared to rising damp where if mould is present it will only occur on the ground floor of the property. Water will collect on windows is a common symptom of condensation in homes.
Damp proof course about 25 mm thickness in cement concrete (1:1.5:3 or 1:2:4) combined with standard water proofing agent is applied evenly to the entire width of plinth level and is measured by multiplying the length of the D.P. course by its width in square metres.
Types of Damp Proofing CourseElectro-Osmotic Damp Proof Course.Chemical Damp Proof Course.Pressure Grouting.Membrane Damp Proof Course.Integral Damp Proof Course.Cavity Wall Damp Proof Course.
A Damp Proof Course (DPC) is an impervious layer built into a wall. It is placed above ground level to prevent moisture rising up the wall via a capillary action. Older buildings used a range of materials for a DPC, including slate, bitumen, jute and hessian. Nowadays plastic DPCs or chemical injection DPCs are used.
150mmThe Building Regulations require at least 150mm between the dpc and the ground or any paving. This is what is known as 'Best Practice'. However, there are situations where it is just not possible, or practical, to maintain this regulation.
Taking the patio above the dpc will put the building at risk. If one is to raise the ground level to above the original DPM, one is affectionately bridging the system to prevent rising dampness and in this case , lateral penetration of water .