First, let me say, waterproofing is my vice - I have done a lot of DIY over the years but water always trumps me. I'm glad you guys and gals are here for advice.
Our house was built in the 1950's and on our covered concrete patio we have a small room built that serves as tool storage. It is original to the home and we've recently cleaned it out and intend to expand it a bit.
Current construction is simply studded walls (sole board secured directly to the concrete slab) with a outdoor paneling type material covering it. Over time, two things have happened. First, the sole plate has rotted nearly entirely which is to be expected for a 50 year old 2x4 I suppose. Second, water coming in under the wall has done what water does and made a mess of the floor inside.
We're installing channel drains soon which should make the patio a more dry place in general. It's rare that enough water gets onto the patio to make it to the building. However, in rebuilding the walls for our tool room, I would like to make the bottoms of the walls water tight. The patio is exposed to the elements - but we would like to keep the contents of the building as moisture free as possible.
Question 1: How should I go about this? I have reasonable DIY experience but I've came up short trying to make the bottom of the walls watertight since the inside and outside share the same concrete slab. Is simple L shaped flashing all around the edges and sealed with caulking enough?
Question 2: Two walls of the tool room are exterior facing - they face our back lawn. The tool room sits in the corner of the slab. There's no barrier between the lawn and the slab on these walls and the only thing stopping water from entering is the paneling type material. Not efficient, as you can imagine. Certainly, we will be installing french drains along the edges, but I feel like I should treat these as exterior walls to some regards and waterproof below the surface of the lawn. How should I go about water proofing in that case - when it's wall vs. yard and not wall vs. slab.