The Brew Cabin

Due to levels and the need to ramp up to a door the finished paving level will be less than 150 below the DPC. How do I avoid damp problems. Can it be done with a bitumen application and if so how far up & down the wall should it go?

How much of the paving will be less than 150mm below dpc? Is it just the doorway ramp, or is it much more than that?

Document M of the Building Regs makes provisions for ramped access to doorways, and there are now several methods of creating a ramp without compromising damp proof integrity. However, if your project involves a considerable area (say more than 3 linear metres) that will be less than 100mm below dpc, then an alternative strategy will be required.

The exact situation, the type of paving, the distance between dpc and paving, the total area, the falls....all these need to be considered before recommending a suitable strategy.

Ignoring the ramp to the door, site level problems require the block paving (which in all cases falls away from the house at from 1:60 to 1:100) to be from 150 below DPC level up to 110 below DPC over a distance of about 2.5m either sid eof the high point. The block paving construction is 60 blocks on 50 sand on 100 sub-base. I would be grateful for an indication of what options are available.
As to the door ramp what options are avilable in that situation?

If the paving reaches a maximum height of 110mm below dpc, I really wouldn't worry about it, as long as the paving falls awy from the wall. You state 1:60 as the max fall - could this be increased at all. I'd prefer to see 1:60 as the minimum fall.

The threshold ramp - you could use a length of drainage composite (see Fin Drains page), or even a length of linear drain, but for a simple threahold to a private property, you could get away with tanking the brickwork to the levl of the paving and/or covering with a damp-proof membrane.