French Drain and paint concerns

[XWORD15]

Three questions...please help if you can!
1. We have estimates for a sealed internal French drains vs. one with a small (less than an inch) gap in the drain. If a water problem occurs from i.e. a broken water pump from the washing machine, will either of the above let the water on the floor into the French drain system?

2. What is a mira drain? Can the use of a mira drain (dimple board) be related to the above question?

3. We are having the concrete walls smoothed (from spalling)and then patched with hydraulic cememt. We are then having the walls painted with a waterproof paint. The floor will be painted with 3 coats (one contractor) or cosmetically (another contractor by our request). There are no cracks on the floor. We have some cracks in the wall but water does not seem to have come in from them. Are there any brands of paint or hydraulio cement that are poor performers and should be avoided? No one is using Dry Lock.

We are very confused. Any help would be greatly appreciated. Thank you!

[EBS Engineering]

1. Internal Drain
I understand the French drain (internal drainage system) but I'm not sure what you mean by the alternative (a small gap in the drain). Internal drainage systems are typically installed to manage a high water table under the house or water coming in through the basement walls when installing a weeping tile outside is not feasible. As a result, it will do essentially nothing if you have a water problem internal to the room (i.e. a broken water pump or washing machine leak). The typical floor drain is supposed to deal with that but never seems to be where you need it when there's a leak.

2. Miridrain
This is just a brand name for an air-gap foundation membrane - rigid plastic used to drain water along the foundation wall (internally or externally). This is typically installed with an interior drainage system when it is along a perimeter wall but again, wouldn't be of any use to you if your washing machine sprung a leak.

3. Painting, Parging
I am assuming you are having the basement walls smoothed out for cosmetic reasons. Is the foundation wall stone/rubble (a century home) or are you smoothing out a poured concrete wall that shows honeycombing? If it is stone/rubble and if there is any significant amount of moisture coming through the wall (leaks or condensation) then your parging and paint will eventually peel off. How soon it comes off will depend on how damp the wall is. Old walls are typically best left alone.

If the wall is poured concrete, then parging it should be fine but it will depend on how well the wall is prepared first and what additives are in the parging (the more the parging bonds with the concrete the better the finished product).

With respect to the floor, I assume that the concrete will be your finished flooring (eg. no carpet, tile, etc.). If so and if you have not noticed any water issues, the coating should be dependent upon how much traffic the floor will have to deal with. If the coated concrete will be covered with something else then don't bother painting it at all. As a general rule, concrete needs to breath.

[FIXITGUY1971]

I noticed you had mentioned small cracks in the wall. I think you should look into stabilizing the wall before the cracks grow larger. These cracks usually don't leak because the backside is pinched closed and water is going further down on the outside before accumulating along the wall. Once a wall has cracked interior tuckpointing is only cosmetic...not structural.

[XWORD15]

Thank you.