What does the engineer have to say about the issue as it does seem he would be the person to ask?

Still waiting to hear back from our engineer. ::

I don't see how it's the contractor's mistake if he was building to Code in accord with the plans you provided him approved or designed by your engineer.

How any engineer could omit a waterproofing membrane and weeping tile in other than a desert is puzzling.

Running the downspouts underground and far from the foundation is an excellent practice.

A French drain is usually installed under an existing basement slab because there was no waterproofing installed on the outside of the foundation wall.

In my experience, an engineer would design the structure of a house but not write the waterproofing specification although he could do that if he wanted to. Did your contract with the engineer say he would prepare complete construction documents?

Was the general contractor not involved in the design of the house? Why would he not at least advise you to install waterproofing on the exterior of the foundation wall if he was aware of the site local conditions and was an experienced builder?

As for the building code, you didn't say where the project is located but the 2009 IRC says:

R406.2 Concrete and masonry foundation waterproofing.
In areas where a high water table or other severe soil-water conditions are known to exist, exterior foundation walls that retain earth and enclose interior spaces and floors below grade shall be waterproofed from the top of the footing to the finished grade. Walls shall be waterproofed in accordance with one of the following:

1. Two-ply hot-mopped felts.
2. Fifty five pound (25 kg) roll roofing.
3. Six-mil (0.15 mm) polyvinyl chloride.
4. Six-mil (0.15 mm) polyethylene.
5. Forty-mil (1 mm) polymer-modified asphalt.
6. Sixty-mil (1.5 mm) flexible polymer cement.
7. One-eighth inch (3 mm) cement-based, fiber-reinforced, waterproof coating.
8. Sixty-mil (0.22 mm) solvent-free liquid-applied synthetic rubber.

Worthy - So, you think we should go back to the engineer?

Renovator8 - Yes, the engineer prepared all our structural documents and worked with the architect on the plans. Our contractor was hired after our plans were approved and as we were getting permits. We made some changes to the plans with our contractor, but drainage never came up (changes to plans were ones we thought of... like adding windows; never really thought about drainage because we never had an issue before).

Our contractor has worked in our area since at least 2000. And in drilling our piers and excavating (we're downslope), he noted how much water there was. We live in the hills of the San Francisco East Bay. This is a remodel/addition.

How could we find out if R406.2 applies to us (e.g. high water table or other severe soil-water conditions exist?)? We had a geotechnical engineer look at our soils, so should I just ask him?

We're still waiting to hear back from our structural engineer...

I'm sure you will get good suggestions from the pros . . .

Isn't drainage typically addressed by a civil engineer (as opposed to geotech or structural) or landscape architect? We were told that recently there has been more focus on runoff/drainage from local building/planning depts because of California's stormwater management plan. Our local dept. required a civil engineer's report for permitting.

Good luck.

This post was edited by Oaktown on Tue, Oct 1, 13 at 16:04

A French drain is any subsurface perforated drain pipe that is installed in gravel but in the US this term often refers to such a system installed on the interior of a foundation wall instead of the exterior presumably because only the French would put a drain on the wrong side of the wall.

I assume the foundation, slab and backfill are already in place and that water is getting into the basement from more than the one hole and that the proposed drain will be cut into the basement slab and terminate in a sump pit where a pump can remove the water. If not, please be more specific about the situation.

The design of subsurface drainage and waterproofing is normally the responsibility of the architect when one is involved. The soils engineer would be concerned with soil bearing capacity and the structural engineer would be concerned with the entire structure. However, in most jurisdictions anyone can design a house so it is up to the owner to assign responsibility for different aspects of the design. The bottom line is that the person who wrote the specification should have included a description of the subsurface drainage and waterproofing.

Perhaps the architect and the engineer each thought the other would design the waterproofing and drainage system but to me it is very odd that the contractor and the building official didn't catch such an obvious omission. I specify spray-on waterproofing and footing drains for any basement regardless of the nature of the soil, site slope or surface drainage. It's simply cheap insurance.

There are companies that specialize in cutting the slab back from the foundation wall and installing a perimeter drain which is a special kind of French drain since there is a slot left open along the wall to catch water from the wall as well as the ground. If there is a good layer of crushed stone under your slab, a sump pump in a pit might adequate.

Reno, I got a good laugh out of this line "this term often refers to such a system installed on the interior of a foundation wall instead of the exterior presumably because only the French would put a drain on the wrong side of the wall."

dam duplicate posts!

This post was edited by millworkman on Wed, Oct 2, 13 at 13:08

Still no word from our engineer, but my husband talked to the contractor (sadly, we get very different results when we talk to him). The contractor is going to fix the hole that led to the flooding, admitting to my husband that that was their fault (he was insistent that it wasn't with me).

But we will cover the change order for the French drain. The plan is to run the French drain on the exterior of the house, from the upper level in the front of the house, around one side, to the back. I'm not sure if it will just end at the back of the house or will continue down the hill to the bottom/back of our backyard.

They did put a bunch of gravel down under the basement foundation, but I'm not sure about our existing foundation (house originally built in 1952 or 54). Our existing foundation are like big columns into the dirt (footings?), not a slab. Our new basement foundation has a bunch of 15-28 ft piers and a slab. And then they added some new piers in the rest of the foundation and retaining walls for the basement level and the middle floor (total house is 3 floors, including basement/bottom floor).

So, I think I get it now. Someone (architect, engineer, contractor) or everyone sort of dropped the ball here with regards to our drainage. Our contractor didn't include that in our contract, so we pay for it now. Bummer, but not a huge deal since it's not like we're paying for something extra, if that makes sense.

Thanks for your guys's advice!!

Isn't that frustrating? I don't get that much (I'm tall and have dark hair) but I have a few short, blonde friends that seem to get that attitude a lot.

I think it also helps if you can talk the 'language' so you might want to do a little research on construction terms and electrical, plumbing, finish work, etc. You don't seem to get much respect from your contractor, but it's never too late to get those subs in line! :)

I'm glad your husband was able to straighten it out. Hope things go smoothly from now on.

lavender lass -- totally. It's almost funny b/c my husband is waaaaaaaaaay less involved in the remodel and has less construction knowledge than I do. Usually for things like this when I'm like, you need to go talk to him and say x, y, and z. Or I have to send messages from his email b/c it's so much more effective that way. I'm pretty good with my façade when I'm with them (wouldn't say things like the big column things for the foundation!) and the subs are much better with me, but I'm thinking it's because I'm not paying them (directly), so they're happy to spend more time on stuff! LOL. But I get the same thing at work... it's tough to be short, young, and female, but I do have dark hair! LOL.

LOL! At least you've won half the battle! It's so unfair that people still act this way. I'm hoping our culture will slowly start to change. Do you watch Once Upon A Time? My niece loves that show and Snow White is short, with dark hair...and can totally take care of herself! Have you seen her with a bow and arrow? :)

In my experience as an architect, I am normally responsible for the complete design of a project. I would therefore hire the geotechnical engineer, the structural engineer and any other consultant need and bill the fees of those consultant to the owner as a reimbursable expense (ie with no mark-up).

To me, any other arrangement would virtually guarantee design errors and place me and the owner in jeopardy.

Renovator8 -- yup, we've had lots of errors! Hopefully, we're catching them as we go, but it's been a bunch of headaches for me and, especially, our contractor.