Thinking of building a house in NE OKLA (40 miles east of Tulsa). Soil is pretty tight but permeable with little or no clay content. This is basically flint rock country with sandy loam. Have heard that the frost line is considered to be 3′ here. Going to drill a water well soon and will take soil samples then.
Dimensions are 32′ x 54′.
I am considering under slab copper pipes sheathed in black PVC with no soldered joints below. Wondering if the lines should punch up through the exterior sill plates or about 2″ inside the plates.
Should I use a 3 pour, 2 pour, or a monolithic pour with post cable tensioning? What kind of reinforcement should be used in the slab for the first two? Should 3000 or 3500 mix be used for the slab?
I don’t think pier and beam construction is necessary here. That was used on my first house in Tulsa and saved me a bundle in repair costs in later years due to the clay content in the soil there.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
Replies
copper pipes for what ?
potable water ?
heat ?
either way, i would probably run PEX rather than copper.
carpenter in transition
Why PEX instead of copper water pipes? I've had copper water pipes (thru the slab) in two different houses for 40 years and never a bit of trouble with them. I'm not familiar with PEX.
Heating vents will be in the attic.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
Copper is through the roof for cost these days. PEX doesn't need all the solder joints and can take a gentle bending. Copper and cement make bad mojo together. You sheathed the CU pipes before bec of that, but with PEX you don't have to. You'll save both on labor and materials with PEX over Cu.
Mike, consult an architect.
mike
That wasn't nice.
My post wasn't meant to be sarcastic or mean. Mike asked questions about post tensioning, strength of concrete etc that a qualified person such as an architect or engineer could only answer. I have never seen post tensioning on a house, only parking garages and other concrete structures in commercial work. That's why I said to contact an architect.
mike
I think it's more useful to the poster to tell him tensioned concrete is highly unusual in a single family residence, but if he wants it that's where to get it. You don't need to be a professional to be right about that. ;^)
Splinter -
See my reply above.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
My bad. The only posters i recall here who spoke regularly of post-tensioned concrete slabs were in Texas, building for highly expansive clay soils. I've never seen one, but i should not have said "highly unusual" - a term like "highly regional" would have been a better descriptor.Hire an engineer! <G>
I think they use it here cause it's fast and it works. Usually on the 3rd day after breaking ground, they have poured the concrete. Dig the trenches, set the plumbing, lay the plastic, tie the reinforcement in the trenches, set the forms, add the cable, and pour. All, without a word of english being spoken!
Sometime toward the end of the 2nd month, a bank somewhere has a new mortgage.
I'm really not kidding above. Last thursday morning I went by a lot where a tractor was blading the ground. Yesterday evening (tuesday), the slab was finished. That period included 3 days off for labor day. Tomorrow they'll probably start the framing.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
House are sprouting like over-priced mushrooms here, too, and some with a similar life span. Only the "cities" in MT have inspection, not rural areas, so some godawful stuff is getting thrown up. I'll prolly be stuck with my latest remodel for a few years, when all this surplus slows our hot market down. Ah, well, gotta live somewhere...and it's paid for. <G>Have you considered a full basement? My last two houses have had walk-out basements, with the shop in the lower level and living quarters above. It's easily 20 degrees cooler downstairs in summer inside, even with the garage door up...very pleasant to woodwork even in summer down there.
I know of no houses in either Texas or OK that have a basement. Maybe some of the older homes do in the northern hilly areas. Down here, they'd just fill up with water, gators, and water snakes. We have gators in this area (Katy). A 10 footer was found 1/2 mile from our house about 2 months ago.
This is the coastal plains with a slope of about 1' per mile. We're about 100 miles from the gulf and the elevation here is about 120 '. Nearest thing that could be classified as a 'hill' is 50 miles north of here.
You still post over in Woodworking? I quit my handle and knob business. To many orders and not fun any more. Was making good money, just not what I wanted to do anymore.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
I didn't realize you had ended your woodworking business. Still, the basement idea is good if you still have your shop set up for yourself. The 'gators would have to hitch a ride to Tulsa, right? I'm a pretty light contributor to Knots these days. I was out of the woodworking loop for about three years while i worked on a remodel, [mis]managed marital matters, and traveled. The 'woodshop' remained in a heap while i played carpenter instead. Now that i'm getting ready for trim and wainscot i've spent this last week organizing it all finally. Art fairs seem to be a dying enterprise and it was getting like your business, not fun anymore. I still have about $10K in exotics on hand so i'll likely sell to galleries when i start production again.
Splinter -
Were I limited in size of the lot I might consider a basement. Or, if I wanted to put in an elevator. (I hate stairs)
But, I've got 60 acres I can set this house on and room for all the shops and barns I could ever want. Mostly though, at this stage of my life, I just want a covered porch and a large view where I can watch the deer, turkey, and squirrels play!
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
Most, if not all, new houses in the Houston area use a monolithic pour with post cable tensioning. Highly predominant in this area. They're selling a thousand a month out in these parts made that way. I've been here 20 years and that is all I have seen used.
In Tulsa, it was usually footing-beam-slab or pier-beam-slab. The builders there that knew their business did test holes and used the latter if necessary.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
http://www.ppfahome.org/pex/faqpex.html
http://www.wirsbo.com/index.php?id=33
some good reading for you.
here is some more from the doubters and lurkers:
http://www.plumbingsupply.com/pex.html
50 years is the magic number for copper buried in concrete slabs to start failing. (at least in our area)
we see radiant systems in concrete slabs that pinhole and fail at 50 years regularly.
not bad, you say, right ? 50 years ?
the problem is that a lot of these homes are built on a slab with the exterior and interior walls bearing on the slab. sort of a nightmare to put in a new radiant concrete floor when this one leaks, isn't it ?
carpenter in transition
Thanks Timkline! I had already found one of those web sites.
On the advise of my uncle, who worked in the cathodic protection group for a gas pipe line company, I buried a block of magnesium and tied it to my copper line where it entered the house (my first house up in Tulsa). He also provided the magnesium block. Never had any pinholes there, but some of my neighbors did. Soil there was mostly clay.
My next task is to talk to a concrete man up there that has poured lots of slabs in the area.
Once, on a summer job while in college, I helped hand pour a 2' tall x 8" wide bond beam on top of a 8' tall concrete wall. This was on a remote site in the middle of the Arizona desert and the A frame that had a cement bucket was broken. About 8 of us, using 5 gallon buckets and scaffolding, poured that sucker in 2 days, daylight to dark each day. Was about 100 yds distance all around the wall. Most physicially demanding job I ever did in my whole life. We had one very large Navajo that started out on the ground. He was filling the buckets almost clear full. After about 30 minutes of that, we put him on the 2nd rung. The next time he got on the ground he filled the buckets about half full!
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
How to do this foundation / slab?
We have a soil boring done and tested by a soil test lab / soils engineer. We then submit the test to a structural engineer who designs the slab. Our cost for the soil test / analysis and foundation engineering is about $2,000.00 total for one of our average slabs / 5000 SF.
If you go to bestpractices then foundation you can select the post tensioning slab video. http://www.hgtvpro.com/hpro/pac_ctnt_ihdr/text/0,,HPRO_20976_28891,00.html?ref=ribbonFor my radiant floor heating system we used pex. In fact we put in a couple extra lines in case any of the other ones failed for one reason or another such that we could just swap them. Probably only provides protection for some types of failure.I was thinking if I had to so my slab again I might think about embedding the geothermal lines under the slab in the soil such that when I could afford it I could install a geothermal heating system instead of having to bore vertical trenches in my rather small yard. The radiant floor would interfer with the ac properties so I'd have to think about some kind of radiant barrier b/t the slab and the underslap geothermal piping though. Anyone done this?
Dude, I live in South Texas. Sorry, but you are barking up the wrong tree when asking me questions about heating a slab. Our coldest month is February and the median temp is 62. Do you or any others know anything about cooling a slab? : - )