What distance can pavers be from weep holes?

TimGeo

I have just completed my deck and about to plan for my next task of building bluestone pavers in a stepping stone style. I planned to have the top level of the pavers at approx 150mm below the F.F.L of the deck which coincidently is the exact level of the bottom of the weep holes of the house as seen in the photo.

I will be using about 100mm thick of concrete pad per paver ontop of a base so I will be moving some of the existing material around to level it out at least so the base is on a somewhat level surface.

I haven't decided what material to back fill between the crushed base and the pavers to fill the gap, but essentially the substrate top surface will be 10 to 20mm below the weep holes.

I may even back fill most of the way with soil, and a layer of stones or pebbles to satisfy any ventilation issues with the weep holes, that way I can at least plant ground cover between pavers and still be freely draining.

I would like to know if this will be ok, and perhaps any tips, I know the minimum should be 50 to 75mm space but I'm taking drainage into consideration 

MitchellMc

It's likely a bit difficult to give you a concrete answer there @TimGeo. 

Weep holes serve two main purposes; they allow any moisture in the cavity to drain out and provide ventilation. As long as the weep hole can drain moisture and ventilate the cavity, it operates as intended. If your fill is not above the dampcourse line, then I can't see you introducing any moisture into the brickwork either. Your dampcourse is likely in the mortar line directly below the weep hole. 

The regulation of 150mm clearance to ground level and 75mm to concrete is there to provide a buffer in the case of a torrential downpour. These clearances should be adhered to if you are in a high-intensity rain area. Whether your backfill substrate is considered the ground level, would be up to interpretation. If you're using soil, then it would be. If a flood of water comes through, it will run straight into the weep holes.

You also need to give consideration as to any termite treatments and whether access to the slab is required for them.

Please let me know if you have any questions.

Mitchell