Water leaking through exterior floor and wall base

Question

My Steel Frame house is built on top of a concrete foundation. Since we do not have the funds to cover the cost of the whole house we needed to have the possibility to add more rooms later in time. GC and Architect were ok with this approach and designed the project considering that.

The foundation was built with that in mind, so apart from what the house currently needs, there are around 13 square meters more of foundation towards the front of the house

Thing is that once the siding was finish and the house should be water proof, we started to notice that water was leaking from some place. We sealed every single place that could cause this started hosing water to the exterior walls were the water was.

The following 2 pictures illustrate the water filtering through the floor of the front wall

There are 2 inconvenients: 1- the foundation cement coat are leveled towards the house, so any water poured on that floor would go directly to the house instead of flowing away from it to the garden. 2- that part of the house has no "step" because of the foundation that was laid down for the future expansion of the house.

The contractor and the architect told us to put exterior flooring to act as a barrier and fix the level of the floor.

We actually did this but. it didn't work we also tried to put some roof membrane to the base of the exterior wall and put the flooring on top of it. with no results as it can be seen on the next picture.

Foundation before filling it with concrete

affected exterior wall and future expansion foundation surface

Front foundation and affected exterior wall and typical mate infusion from Argentina.

There's no way we can proceed to install any flooring with this issue not being resolved, and that's not allowing us to move in. Although its popularity is growing steady, Steel Framing experience is very little in Argentina.

I would really appreciate any insights or advice on this matter. Don't hesitate to ask for more information I would be glad to provide it.

edit: link to the imgur post

Edit 2:

After it dried, I did some water tests which illustrate how the water flows in**

affected front wall from the inside. Dry

main doorway corner

Answer 1

Well, as you can see, there is a reason for building the foundation up, or the whole slab up. You can put some kind of water barrier to stop, what you are experiencing. You know that, sorry. My thought of a solution would require you to cut a set of paralell slots, up against your house, close to the sill as you can. You'll have to remove the siding, a couple pieces up, all the way around... anyway I would. Make the slot at least 6" wide. You will need a Tiling spade, it has a long handle, and a long narrow spade! You are not in a frost area, water is your problem. I'd still make the hole 18" deep, and the top up 12". If you taper the space wide, from top to bottom, that's even better! This will be one pour. on the back side (wall side) you will need a strong waterproof membrane. Overlap and seal at the bottom of the pour, the same on the front of this "kick wall" but have it long enough to go back up under the siding from the in and out side. You may have to glue it on the top of the cill. A piece of copper flashing or allumium, coming down over the membrame, under the siding. I'd get 12" wide flashing, so a Z bend can go all the way over the cill. Do this but for your doorways, and you will no more seeps into your slab, metal frame house. It is a fair amount of work, the head guys on your contractors crew, should be able to cut the deck. Then the younger boys dig the footings, and the older guys measure the total width of the membrame. They need to put up a frame to pour into. Make sure the "boyz" taper the cill OUT from the house! It will require a few screw or fewer bolt holes in your deck. After the cill is dry, lap up the membrane, seal it on top, and add the Z flashing, put the siding back on. It is not a terrible solution, but it will work! See what others say, not something we see here up NORTH! :)