Site Grading

[heath568]

I’ve been reading this forum for the last few months and learning a lot from the posts here. It’s great to have a great resource like this.

I’m planning to start building my house next spring and have been thinking more about site placement, drainage, driveway, and eventual site grading.

I’m familiar with using a transit to set sightlines and a grade rod. My father retired from the road construction business and is more than willing to show me more than I need in that aspect. But with the new laser systems is it possible to combine this? I know that the cheap models wont shoot over 100ft, but I’m building a house and small steel outbuilding on a one end of a 10ac site and think I could possibly do it with a laser level and a grade rod? Using a laser level I could then use it for other projects inside the house later. (trim, drywall, pipe runs ect…)

I know that I will need to use something because I have been around sites that “eyeballed it� causing the owner to be unhappy later when the drainage was not correct.

My plan was to excavate the site with my tractor. (Case IH 1594 MFWD) I will take off the topsoil in the area and store it off to one side to be reused for final topcoat. Then remove the clay base underneath to make a 36’ X 48’ X 12’ walkout basement. I’m in Kansas and the relative elevation drop for the whole site is 15ft from high point to roadway. (I know that seems easy compared to you folks in the hills with rocky soil.)

I know someone has some tips out there that will be handy.

Thanks

Heath

[Nat]

I can tell you 1 thing, no matter where you put the topsoil pile it will be in the way of something. I think it is a law or sonething. Make sure you include a lot of pics of your progress as you go along. It is interesting to see the differences in construction in different parts of the country.
There are a lot of knowledgable people on this board, and most of them spell better, and type better than I. I will try to answer any questions that I can, having just gone thru it myself, I know that there is a lot that comes up during construction. Later, Nat

[Pat]

Heath, You might want to share some details on your drainage plans-systems-ideas for your walk-out basement. We excavated a lot of dirt to give us a walk-out basement. Our finished floor height in the basement is a few feet below the typical average ground water height and so far no water problems in the basement.

The only water penetration into the basement was when I was back filling around the walls with a lower level of gravel covered with geotextile and topped with sand. I used a 2 inch engine driven pump to turn the sand into a slurry in lieu of using a plate compactor with short lifts.

At one point I got the water higher than a hole in the wall sleeved with PVC for a ground sourced heat pump line to a well field. Put a lot of sand in the basement! I have a shovel and wheel barrow so NO PROBLEM.

The cast walls used "snap ties" in the forming system which creates little pathways for water ingress. It takes a head of pressure to force water through those pathways and I provided that with a considerble depth of water-sand/slurry. There was just a trace of a trickle of dirty water stain on the inside of the cast walls at some of the snapties. We have had some realy TEXAS FROG STRANGLING rains since and no leaks, at all. None of the sand used in the back fill is exposed at the surface. Porch or other slabs cover it all.

I insulated the outside of the basement wall with rigid foam sheets (InsulDrain) which has drainage chanels in it on the side away from the basement wall. The chanels are covered with a sheet of Tyvec filter cloth to keep fines out. Any water getting to the insulation falls to the botom where the French drain is and does not make a head of pressure so the walls have never leaked since the great back fill slurry exercise. I think I detailed most of this in the Oklahoma Farmhouse thread.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[brent]

Hello Heath,

We are building a new house also, and I had concerns about drainage issues around the house and water table, Our builder rested my mind with putting tube socks on the inside and outside of footings on the basement(see pic) with a sump that will pump any water out from under the floor or around the footings of the basement. Being 3 ft above the water table and with the waterproofing the builder put on the walls, some would say it was a overkill putting the sump system in, but to me it was cheap insurance for possible issues down the road.
http://webpages.charter.net/bone5258/pic6.jpg

Good luck with your project.

Brent

[Pat]

Heath, We also excavated an "intercepting trench" on the uphill side of the basement. The trench is about 6-8 ft up hill from the basement excavation and has a French drain in the bottom. It drains at both ends to daylight, after a fair horizonal run. As ground water comes downslope in a layer of sand atop a layer of rock, that water which would have gone into where the basement is falls into the French drain and goes away. This French drain has been running a constant stream of water for 2 years.

I hired a PE soils engineer/structural engineer who hired a sub with a drilling rig and we took soil samples every 6 inches in a test bore. Based on our findings he made recommendations which I followed. Water proofing a basement wall is a good idea but how do yo insure there is no entry point for the water. Sump pumps are a good backup to a waterproofing system because water proofing is quite difficult, long term.

I have no sump pump and my cast concrete walls are not waterproofed. I have absolutely no water penetration since the backfilling episode. A head of pressure is required to force water in through the cracks (all concrete has cracks.) Water proofing systems can fail or have or develop flaws. We chose to design such that there is no standing water on the walls.

With the basement floor poured monolithic to the stem walls, 2 ft above excavated grade and the top of the foundation we have about 16 inches of gravel above excavated grade under the floor. With a French drain at the height of the foundation both inside and outside the foundation, water would have to stand 16 inches deep over two 4 inch drain pipes to wet the floor. Water can't get to the walls faster than it will drain away so the walls have no water pressure to force water in through any cracks. It is theoretically sound and is working in practice.

The professional soils and structural engineer plus the drilling rig and operators plus the soils testing and copies of the report with the PE stamp on it cost less than $1000 and was money well spent. I feel good knowing we designed the foundation and water handling from a position of knowledge rather than doing whatever some good ole boy thought was plenty.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[heath568]

Whoops...... I wasnt watching for replies.

After talking with my dad and one of his old friends I think I have the site grading issue handled. It is high enough and flat enough that even with the walk out basement there is enough drop for good water runoff.

Bad news is that with the hurricane last week looks like building materials will be rediculous for a year or so....

I'm not in a hurry though.... Might wait a year and then start.

Thanks for the replies.... I really enjoy reading about and seeing your projects.

Heath