I want to build a storage under ground, beneath my existing entrance/patio. The entrance area has 3 existing walls (masonry) that continue underground to the basement floor. (3 walls like a U)
What is missing to create a storage is excavation, the fourth wall, floor, and ceiling. How should a good construction look like for the ceiling, which will also be the floor for the outdoor area (wood deck)?
-span is about 2200mm, total area about 12m2
-as thin a construction as possible
-insulated, waterproof, sloped for water drainage
-is an expansion joint to the existing walls necessary?
-wood construction or concrete?
Can someone help me.
Best regards, Mattias
