The Damp Proof Course (DPC) level is typically found by visually inspecting the exterior walls of a building for a horizontal line of material, often slate, plastic, or a similar damp-proof material, usually located above ground level.
Here's a breakdown of how to locate the DPC level:
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Visual Inspection: Look for a visible horizontal line of a different material (e.g., slate, plastic) in the brickwork or masonry of the exterior walls. This line usually runs continuously around the building.
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Location Above Ground Level: The DPC is designed to prevent rising damp, so it should always be located at least 150mm (approximately 6 inches) above the finished ground level. Look for the line above the surrounding soil, paving, or other surfaces. This height complies with most current building regulations.
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Bed Joint Identification: The DPC is often installed within a bed joint (the horizontal mortar joint between rows of bricks or stones). The DPC material will be visible in this joint.
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Check for Weep Holes: Sometimes weep holes (small gaps or holes) are present just above the DPC. These holes allow moisture to escape from the wall cavity.
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Internal Check (Less Reliable): While not as definitive, you might be able to estimate the DPC level internally by correlating it with the external height. However, internal floor levels may not always precisely match the external ground level due to insulation, screeds, or variations in construction.
Why is the DPC Level Important?
- Protection from Rising Damp: The primary function of the DPC is to prevent ground moisture from rising up through the walls of a building through capillary action, which causes dampness and potential structural damage.
- Building Regulations Compliance: Adhering to the minimum height requirement (150mm above ground level) ensures compliance with building regulations.
- Property Value Preservation: A functioning DPC helps maintain the integrity and value of a property.
If you are still unsure about the DPC level or suspect an issue with your DPC, it is advisable to consult with a qualified surveyor or damp proofing specialist.
