Hi
I have a house built in 1991. I recently raised the level of the tarmac driveway to achieve a better gradient. However, I have noticed that on a very small section of the front wall of the house, the DPC height has been breached by about one inch, ie the dpc is now 5 instead of 6 inches above the ground. Does this regulation apply to a house of this age and would it be a problem when it comes to selling the house? The front of the house is sheltered and the gradient means the ground never remains wet for very long. Any advice would be greatly appreciated. Thanks
Are you a tradesperson and able to answer this question?
Hi. Dpc should be minimum of 150mm above any ground contact with the wall. This could be remedied by cutting back the asphalt and creating a French drain with 20mm gravel.
Regards
Iain
Although the required standard is 150mm below the dpc plenty of properties don't comply - often due to new paving additions or garden levels changing. If you've never had a problem with damp then I wouldn't see it as a worry at all. If you were concerned about affecting sale of the property the first thing to do is have a damp survey - to show whether it has allowed any damp penetration.
The approved documents of the Regs state that a dpc height of 150mm will satisfy the Regulations. The reason for the 150mm is to prevent the base of the wall becoming damp via 'splashback' of rainwater as it bounces off the adjacent ground. The Docs also state that “the requirement can also be met by following the relevant recommendations of Clauses 4 and 5 of BS 8215:1991”. One way which has been accepted by Approved Inspectors, where a good dpc is in place but it does not reach the 150mm hight requirement, is for the base courses of the wall (up to and ideally above the 150mm height) to be protected with a liquid applied sealant which will make the brick surface impervious. One such product is Stormdry Masonry Protection cream. A secondary benefit of applying masonry protection cream or similar is to prevent the face of the bricks below the dpc becoming damp and encouraging green mold
