Raising garden terrace by 150mm DPC considerations...

[mikeinthemidlands]

Evening

I’m about to install sliding aluminium doors at the rear of my house and I want to raise the outdoor terrace by 150mm as I’m running a 10mm porcelain tile inside and outside.

I would like some advice on drainage and the air vents as the internal floor is block and beam.

I was planning to run Aco below the tiling with a 15mm gap and have a lead flashing with the doors sitting on this feeding any water from the frame into the ACO. The idea is to have a flush threshold between indoor and outdoor. The door manufacturer has confirmed this is OK with the doors chosen.

The fall outside is away from the house 3m to a 50mm gravel bed.

Any advice on how to set this up properly much appreciated!

 

[mikeinthemidlands]

Any ideas anyone? If I could do away with the ACO and just have the 15mm gap that would be ideal.

 

[John D v2.0]

if the door are fine with being down to ground level, then just make sure the paving slopes away from the house and either put a slot drain or just carry on the slope.
Your tricky part would be the ventilation, you might have to duct the vents under the new patio to a step or something.

 

[mikeinthemidlands]

The doors are designed for flush threshold yeah. I was going to sit the frame cill less on lead and leave a small gap before the concrete pad for the air vents. It’s tricky using a drain under the tiles as the tiles are only 10mm so they can’t cantilever over the drain. I’d prefer not to see a drain if it’s not required.

I would have thought the weep holes would only drain a small amount down the lead onto the permeable block paving and therefore it would be OK?

 

[Leofric]

might be missing something but ,apart from obstructing the air bricks if you raise the patio level by 150mm , won't you be building up to the dpc level in the external wall