Joey,

I have been using FAD for years and have had great success with it. I typically won't do a foundation with out it. I have only used fast foot a few times. I have a couple of questions for you.

1. What size FAD are you using.
2. How thick are your footings.

To answer your questions.

1. Yes they work well together but I have only found very few occasions where it was neccessary to use both. You can staple to the FAD but I usually use dry wall screws.
2. No there is not a concern. You will stake the FAD every 2 feet and next to every joint in order to keep it true, the Fastfoot will find its own level from there.
3. No with the FAD prefectly level water will enter and find its own level and follow a path of least resistance to your drain. Remember you are installing a footing drain not a sewer line. All you should be dealing with is water not the effluents that you find in sewer lines.
4. I use FAD inside and out on my perimeter with a cross over pipe or two or three through out. Where I build I don't have the issue with Radon so I use the inside as a drain also. As far as interior footings go, I have used it a couple of time on wet job sites when we felt the extra drain lines would be helpful, but typically if you back fill your foundation with a free flowing back fill like drain rock, pea gravel, and such which is common around the Pacific NW then the need for the interior footings to have drainage also is moot.

ICF Contractor

Thank You ICF Contractor,

My footings are 18" thick. I'm not sure what size FAD I would get, they don't make it as tall as my footings so that's why I figured I could use Fastfoot also. Another way would be to have a partial trench footing.

My thought about using FAD on interior footings was for material savings.

Is there a problem with silt getting into the FAD? Can you put in cleanouts? Snake it?

Joey
eco-hammer

Joey,

18" is a very thick footing!!! How wide is your footing and how tall are you building the structure? These sound more like grade beams. What are your soil conditions? As far as the size of FAD I would go with the 8" because it is stouter than the 10". The only issue I see with a trenchfooting is the placement of your footing drain ie FAD.

Properly installed FAD with drain rock and fabric should not silt up, but it never hurts to put in a clean out. The only issue is there is not redy made coupling to do so. It is something you would have to fab up yourself.

ICF Contractor

Joey:

500' and 18" thick, are you comfortable doing your own footings, I dont mean to sound detrimental or argumentative in any way, or to insult in any way, however with these questions on a footing this large, are you confident in your ability to complete, or do you do this semi regularily.

Again, no insult intended, this is just a lot of footing and concrete.

Mark Ross

Mark,

No insult taken.

It's been about 15 years since I've done a big foundation job. I have a guy in my crew who was lead on a number of three story, multiple unit condos before he became a stay at home dad seven years ago. I'm working with another contractor who is about 100 miles away, they erect 10+ ICF structures a year, he will bring his crew over for the pre-pour check and show up for the pours.

The house has a 2400 sq.ft. footprint but it's a two storey building surrounded on all sides with single storey. We have an interior footing, an exterior footing and a series on interconnecting grade beams to tie it all together in a "floating grid" or "sled" foundation. There is a partial basement under only single storey but it has some common walls with the second storey so some walls are 28' tall.

The site is located in Berkeley, CA on the hills across from the Golden Gate Bridge. The soil is 4ft. of "Brown lean clay with sand (CL), firm, moist to wet" over "Brown clayey sand with gravel (SC), loose, wet to saturted". The boring was taken in April. Maximum allowable soil compact pressure of 2000 psf for dead plus sustained live loads, 3000 psf for total loads, including wind and seismic forces.

Structural Engineer called for a 18"x24" footing with 4 @ #5 horizontal and a #3 stirrup @ 18" O.C. The footings and the grade beams the linear footage is actually closer to 380'.

Yes, I am in over my head, I hope the people I'm working with will pull me out. After all is said and done, it's my job and my (bleep). I'm just trying to build the best house I can.

Some photos from the site tonight.

56 bundles of Buildblock stacked.

Joey, to my knowledge Certainteed forma-drains max size is 12". Personally sounds more like a job for 2x6's and fast-foot along with standard perf drain tile. I agree with all that FAD is a good product for the one timer but since fab-form has come out I think it is a better choice. The fact that you can re-use all the 2x6 (or 2x4) on your project seems like the most ECO friendly choice.

Dave

Based on the price of Form-A-Drain I have only used it once in CA, I found it better and less expensive to use 2x materials for the footing and then add a perforated drain after the wall is complete. I usually use PT lumber for the footing and when finished it can be used for the window bucks - Now that's being ECO-friendly

For those using Form-a-Drain, I have a pail of brackets and I have a banding machine with the tools for banding footings or lumber along with the banding clips for sale. The band dispenser appears to have about 1/2 a roll on it!

Contact direct. I'm in CT

Can you use tyvek instead of the fast-foot?