Concrete Path level with "dampcourse"

[Brianno6]

Hi again
Son is moving in to 1950's ex-Council house, on gable-end there is a lean-to 3 by 4 Mtrs, need to demolish this and re-build a 3 by 6 Mtr extension, snag is the finish floor in the main house and carried in to the lean-to is only around 50mm (2ins) above the concrete path around the house, since I need around 150mm of "Space" between the damp course and path it would either mean that I have to lower the path or have a step up in to the new extension, neither an option, I doubt if there is a "good" damp course around the property due to age, have not had contracts signed yet to have a closer look, this is a permitted development, no plans required, hope you can help and advice.
thanks.

 

[^woody^]

There is no problem with a high external ground level, you just design a suitable DPC detail to compensate on the new extension

Whether the extension will be permitted development, will depend on other factors - check the planning portal for details

 

[Brianno6]

Woody
Thanks for your reply, if I install the new build damp course 75mm under the finish screed it will be under the external path, I have had permission for permitted development from planning.

 

[^woody^]

You would not install a normal horizontal DPC.

You would have a vertical DPC on the inside of the wall below ground, then a horizontal DPC, and then a cavity tray above this

 

[Brianno6]

Woody
thanks again, sorry, but can you explain the position in the footing for installing cavity trays? maybe a link to some web page

 

[^woody^]

DPC in blue

 

[Brianno6]

Woody
Thanks again for your help, obviously the damp course and trays will have to be installed to all parts of the footing, again much obliged for your advice