Groundwork & Foundations

Should I raise external floor to match level of internal floor?

Anonymous user 03/03/2024 - 3.22 PM

I am due to have sliding glass doors fitted to the rear of my kitchen. The external floor level is 20cm lower than the internal floor level. Currently outside there is an external maroon coloured concrete plinth with air bricks every so often within it. (I don’t know the proper name of this – it looks like an external skirting board only flush with the brick/rendered walls). The property is early 1930s construction – solid wall construction (not cavity wall). The rear yard is only 3 meters deep and all concrete (no soilbeds). Ideally the external and internal floor levels would be level following the installation of sliding doors, to make the most of seamless access and transition. Practically and aesethically sounds great. BUT I don’t want to create / self inflict damp issues in the future. Are there builders who have come across this situation before, who can advise on the best course of action? Should I raise the external floor level to match the kitchen level for seamless access, or should I leave well alone, and just accept a big step down into the rear yard? Is this doable? Is it wise? Are there any pitfalls. alternate solutions? I have builder on site at moment, hired to do structural work only (ie fit all the steel beams). There is lots of rubble in the yard at the minute due to digging to create box frame. He is saying rather than putting all the rubble in a skip, an option could be to use some of that rubble to level floor difference internally and externally; and then break the current external render and create new DPC barrier and slope the floor slightly away from the house so as to avoid water ingress. He is going to consider and prepare a price. My question is – am I safe to go down this avenue or best avoided? Leave floor levels alone and accept very big step? Or whilst he’s willing to potentially do the work, given lots of rubble in yard at present, is it wise/safe to pursue? PS – All the photos I look at of sliding/bi-fold doors in magazines all have level floor access internal and external. Any thoughts/experience would be appreciated.