Hello.
First of all, yes, I have spent much time reading the archives about french drains, foundation drains, and houses without gutters. I just can’t seem to mix and match all of that great advice into a solution suited to my exact situation. Here it is:
-New build next spring.
-Build site is dense blue clay, wooded, in Michigan.
-Puddles last long enough for frogs to reproduce (no kidding).
-Two story Prairie, all hips NO GUTTERS, walk out basement.
-Site slopes to wetland, all drains can reach daylight.
-MUST HAVE DRY BASEMENT (promised the wife)
The drainage plan right now:
-Two foot min. overdig backfilled with gravel.
-Poured walls.
-Warm N’ Dry waterproofing.
-Drainage below basement slab (gravel).
-All drains inter-connected between single sump and footers.
-Footers will drain to daylight as well.
-Will use clay to grade away from house all around.
-NO GUTTERS.
Questions:
-Should gravel backfill be capped with clay?
-Should I have a French drain above that backfill for roof run-off?
-Should I just grade away from house and trust footer drains to work?
-Should I have more than one sump? (Hope not to need the first one but it’s code).
-Where should fabric go/not go?
-A verbal foundation cross section description would be a great way to answer my questions.
Thank you.
Replies
Gone,
Your plan as laid out sounds fine. Now to your questions. If the clay is as bad as you say it is then bring the gravel all the way up to finished grade(you can hide it with mulch if desired). If you bring the gravel to the top you should not need a french drain above it, the gravel will be your french drain. You need to grade away from the house in any case especially since you will have extra water next to the house due to the lack of gutters. If you are able to run the drains to daylight then there should be no need for an extra sump. This is a stupid code that some localities require (having to put in a sump even when natural drainage is present) so don't feel the need to put more than one as the one you will have will probably never kick on. Natural drainage is the best of all possible worlds as sump pumps quit, power outages happen, etc. As to the use of fabric I don't consider it necessary but if you use it then it should totally encase the gravel as that is it's purpose( to keep the gravel clean). One other thing, an 18 inch overdig is sufficient but if you prefer 2 feet have at it. It won't hurt any thing but your wallet due to the extra gravel needed. All in all it sounds like you've got it handled. Good luck.
Mark
Thanks for the reassurances. The reason that I am considering an additional French drain involves a detail that I didn't mention in my first post. Most of the house will have 3 foot overhangs. This means that the drip line will miss the gravel backfill by at least 1 foot. With this new information in mind, would your opinion be:
-Send the water back toward the foundation drains?
or
-Grade this water away and let it go as natural run-off?
or
-Add a shallow trench or drain tile directly in-line with drip and send it to daylight?
Other Questions:
If those footer drains will be used basically as gutters, should they be beefed-up in any way considering their constant use?
Maybe a second tile near the surface of the backfill could come in handy during heavy downpours?
Thanks.
with three foot OH, just grade away from house.
The guys setting crete forms are going to want that two foot over dig, especially in blue clay. That stuff kills men with cave ins..
Excellence is its own reward!
"The first rule is to keep an untroubled spirit.
The second is to look things in the face and know them for what they are."
--Marcus Aurelius
Thanks piffin.
When you say "grade away from the house", does that comment mean that you would cap the gravel backfill with a layer of clay to keep as much water out of the footing drains as possible? In other words, start the grading right at the house wall?
--Solo
If you are grading away from the house, beginning at the foundation wall, I don't believe it makes much difference whether you cap it wih clay to seal against water penetration or not because you have a three foot overhang and a two foot fill slice. The drip line is another foot out. I know the wind blows rain but you are putting good underground drainage in. Let the surface take most of the rain away.
.
Excellence is its own reward!
"The first rule is to keep an untroubled spirit.
The second is to look things in the face and know them for what they are."
--Marcus Aurelius
Do any of you fellas have experience with the Warm N' Dry products? This would include that vertical fiber drain board (pink stuff)?
Any other preferred products or recommendations for wall treatment?
Thanks.
piffin, Thanks for helping me figure this out. Considering your recommendations, I've only one problem area left to deal with...
I did say MOST of the house had 3' OH. Actually, the only part with less than 3' OH is a bump-out that is 15' wide and comes out about 2.5' (foundation comes out with it, ROOF DOES NOT). BTW, this was done to get more light into these windows. This leaves about only 6" of OH. Without gutters, that 15' of drip edge is going straight down the wall.
The solutions I'm thinking of are:
-"Drip diverter" in that area like I will have over doorways.
-"Hardscape" just that section with concrete or blue clay.
or
-Not worry about only 15' of perimeter and let it go down to footer drains.
Comments?
If the clay is as impervious as you say, grading should do the trick. Gravity rules!
I'm not sure if I'm misreading your first post, but are you tying the sump drain to the footers drain as it goes to daylight? If so, I'm sure there's a good reason, but wouldn't it be better to keep them separate all the way to daylight, so if a clog occurs, the footers don't drain into the sump? JMHO!Jake Gulick
[email protected]
CarriageHouse Design
Black Rock, CT
In my case, the sump is only going to be there in order to meet local code. In a home where the footings cannot drain to daylight (typical) the sump would have to handle all the water.
--Solo
I'll reiterate what the previous post said: I wouldn't recommend connecting french drain outside the wall to the sump inside the foundation, even with it draining to daylight. House I worked on, the owner-builder did just that, with two 4 inch drains all the way around draining, well sloped, to daylight. Tropical storm, downspout extension comes off, and he finds his basement flooded AND water pouring out the french drain. Water came through the sump hole. . . ruined a nice finished basement.
Thanks for the warning but, the building codes in my locale require the sump as if they're pretending that there is no daylight drainage. So, I'm not sure it'll pass the test if the inspector see a sump with no drain tile connected to it?
Maybe you meant that I should have just the under-slab circuit connected to the sump? I'd have to double check the code on that.
The real irony is that the PUMP OUTLET will be down the hill headed for DAYLIGHT!
Connect interior drains to sump, perimeter drains to daylight. Use clay at surface where you need to. Mu reason for modifying that is that most people want some landscaping shrubbery or whatever decorating the baseline of the perimeter and you'd need topsoil for that. Do the hardscape in front of the bumpout. The bump will be the decoration therre with it's windows..
Excellence is its own reward!
"The first rule is to keep an untroubled spirit.
The second is to look things in the face and know them for what they are."
--Marcus Aurelius
Hey thanks. If I can get that drain design to pass inspection (it should) I'll probably do it that way. I do not like the idea of sending rain water under my basement floor if I don't have to!
To further detail of my idea of the clay cap...
I was planning, all along, to put top soil over the clay. I feel that the clay in my site is so dense that it will determine the true sub-grading that the water will follow. To put it another way, if I don't "sculpt" that clay properly, the water could penetrate the top soil graded away and possibly head in the opposite direction once it reaches the clay layer.
If this sounds like over-thinking, please consider...
-I currently have a damp unusable basement (15+ years).
-My current (low) small lot has all three neighbors with higher land emptying into mine.
-We will live in this NEW house for a very long time.
and
-Promised the wife, A DRY BASEMENT ; )
You can always keep plan B in mind.
Hypnotize her. Repeat over and over, "this is a dry basement"
"this is a dry basement"
"this is a dry basement"
"this is a dry basement"
"It's not damp, it's cool"
"Those aren't stains, they're patternwork from the curing process."
"this is a dry basement"...
;)
.
Excellence is its own reward!
"The first rule is to keep an untroubled spirit.
The second is to look things in the face and know them for what they are."
--Marcus Aurelius
Oh great, just GREAT...
I was just telling her about your PREVIOUS post.
"That guy must be a real pro", she says, "solid advice", and, "that Breaktime is such a wonderful resource...
Hey, in my book, you must be a PRO (and married) if you can come up with a line like:
"Those aren't stains, they're patternwork from the curing process."
Really though, thank you. Your advice is quite timely, as we are working this week on the drawings and specs for the new wall sections.
--Solo
Real pros have more fun! Just like...no I better not say that..
Excellence is its own reward!
"The first rule is to keep an untroubled spirit.
The second is to look things in the face and know them for what they are."
--Marcus Aurelius
Gone,
Just grade away from the house, a second higher drain might help but I agree with Piff in that it isn't necessary. I would bring the gravel all the way to the top because of the blue clay. My experience with this type of clay is that even a few inches of it will stop water from going thru it a long time. With that in mind you want to provide a path of least resistance for the water to get to the drain tile. That is the purpose of bringing the gravel to the top. It is not something I (or Piff for that matter I would bet) would normally do but we are talking blue clay here not red or yellow. The blue clay can create real problems. One other thing you might check into is wether or not your local codes require widening your footers over standard. In some localities (there is one near where I live) that is the case when building on blue clay as opposed to other types of clay. I believe the reasoning behind this requirement is that blue clay has a tendency to have a lot of layers in it and water moves along these lines. I don't know that for a fact but I do know that wider footings must be installed in that area. Good luck.
Mark