Installing Damp Proof Course (DPC) | Part 10 | 6 Car SMART Garage Build

[@ricolaracing]

I'm looking at options for my DPM. Surely moisture can travel through the sides of your slab like that? Do you plan to do an epoxy floor or similar to seal internally? My original plans had the DPM wrapped underneath and around the sides into a drip tray but I'm not happy having an exposed DPM at the edges and J&S weren't happy to guarantee sealing of DPM to piles.

[@sanjdesigns]

Good question and in hindsight this is something that I feel should have been added. Not had any problems at the moment but agree there is a ‘potential’ for damp to permeate along the vertical face. You should discuss this with J&S what they recommend as part of the slab construction or post build to avoid this problem. Wasn’t happy with the floating as finish wasn’t as I’d hoped - this was the builders fault not J&S as he started too soon. Not going to do epoxy because it’s either grey or grey 😀. I’ll be installing the pvc interlocking tiles once the driveway is finished. Much nicer look than epoxy.

[@ricolaracing]

@@sanjdesigns Hmm, J&S just suggested I fit a dpm over the top of the slab and pour a screed as you would conventionally but as the whole reason I need this solution is to avoid affecting the surrounding tree roots I’m starting at ground level and it all adds up very quickly in height! I’ll be installing a lift and will be welding so don’t fancy any of those tile solutions, I’ve previously had light grey and it works well for bouncing light around when underneath. Maybe blackjack on the slab sides and a similar tray as you have done then seal the bottom inner blocks?

[@sanjdesigns]

Blackjack and a tray sounds like a good idea. The blackjack will act as an adhesive as well as a sealant. . Yes more work but hopefully save you in the long run. I still have some of the wooden shuttering around my slab and this will be removed when the block paving starts so I’ll probably do the same. Definitely wouldn’t screed on top as this is more money and time, plus a risk that the screed will crack once you add your lift. Just my thoughts.

[@paulcollins6221]

There should have been a boot detail at the edge of the concrete should never set cavity wall on flat base no need for bitumen if done properly

[@sanjdesigns]

Thank you Paul and appreciate your feedback. Building control viewed DPC and were happy with the build and structure and signed off the stage before starting main blockwork. Regarding bitumen, don't disagree, but its a belt and braces and anything to stop potential damp and moisture is a good thing. Was what the builder recommended and did and don't have a problem with it. It was purely a recommendation and I have seen this on other builds. But is a messy job and time consuming.

[@paulcollins6221]

@@sanjdesigns these young buiding inspectors are not familiar with on site building practice.. Without a boot detail on the edge of the concrete moisture can get under the dpc and travel across the top of the slab