foundations

[Irmobaseball]

Hello,

Will I learn how to create a foundation from the class? The area of North Texas that I live in has black soil that cracks a lot, some years the cracks can be a few inches or more. People in my area are constantly having foundation problems which result in cracked walls and unlevel floors. How will this affect a log home and does anyone have any suggestions to avoid this issue? Another issue is that not far below the soil is rock which certainly complicates the issue. Help me, please.

[ChainsawGrandpa]

Sounds like your area may be perfect for a pier foundation, which is
the type emphasized in the class. I believe piers are best because
they allow adequate ventilation to minimize an early death of the
structure. They are also fast as you are working around piers in the
ground, not an open pit (basement), but the big advantage is that a
pier foundation is fast and almost impossible to screw-up. My guest
house sits on piers that go deep into the ground.

That said, I'm installing a continuious ring foundation. I'm on a side
hill (not good), and my frost line is close to four feet down. This would
make my piers so large that the two types of foundations are almost
equal in cost (plus the added time of building a basement, having to
build around a basement, the cost of a concrete floor, the extra stack-
height of the Russian Stove, installing a second set of stairs....).

You may consider talking with a good soil engineer. Not all of them are
good. I was installing cabinets on a house being built on a combination
of sandy loam, hard pan, and giant boulder. The soil engineer was on
site and she was emphatic that the soil would not bear the weight of a
stick-framed house. She was fresh out of college and sister to the owner.

-Rick

[Timber]

My frost line is 4 feet also--i was thinking easier method rather than me dinging 4 foot holes / amd buildiing 5'6" pier forms was to just get a backhoe operator and trench it for a stem wall-or monolithic pour alla Vern and Sarah Streets place. I am going to check out my options and see what is best. I heard that a stem wall is better against cold than just piers for your pipes freezing. I need more research. I am thinking about getting me a set of the plans. I might be starting sooner than later. Guess that pex plumping does not freeze as easy as copper so i might go that route as well.

[Timber]

Hey you might need someone who knows the ground and what needs to be done to prevent these cracking problems. They can remove dirt and add some--can be costly. Do you own any land?--if not do research to find the hidden cost of building it right before you buy. The log house my class was instructed from was over 7,000sq ft 3 stories and was on concrete piers that they teach you how to build. I am wondering if that ground you are talking bout is moving? You could build on a adjusttable foundation. There is a place out here in CA. the ground is moving alot and the homes are on a ajustable foundation---the thing is though its Costly and could it be done with the log home? not sure--got big $$$$$ you can do almost anything. Concrete piers are the most cost effective method and pretty simple to build with also.

[StressMan79]

Timber,

pex pipes freeze just as fast as copper. But the cross linked polymer does not rupture when the water expands--no damage. However, you would have no water while the pipes were frozen.

The stem wall keeps the temp fluctuations down, and the heat you loose from the first floor (you will lose some) will be trapped by the stem wall, keeping the area under the house above freezing. This separate air pocket also adds to the effective R-value of your floor.

This being said, I would look seriously at piers for this application. you can increase the area of the pad to decrease the stress on the dirt. You can engineer them to be whatever you require. That added to the benefits above--cheap and easy for a non-skilled person to make/install make them very advantageous.

This being said, I think I am doing a suspended cement floor in a stem wall. This is due to cost and ease of installation of the PEX radiant floor system.

-Peter

[Timber]

So i am guessing the only difference would be your floor would be above grade? / Versus the slab on grade cement floor.

[StressMan79]

yep. that is my plan. backfill the stem wall with fill and top off with sand, then 4" polyiso, then ~6" cement with rebar in the bottom half, pex suspended in the top 1.5 in.

The reason for this is I want to keep the floor as cheap and simple as I can. Building Slab on grade is cheapest method of installing radiant floor heating, by almost a factor of two. If you take that I won't have to use joists or worry about frozen pipes, that is just a bonus. OTOH, maintnence is much harder, as if i need to put in a new wire/plumbing run, or fix an existing one, I won't be able to just get under the house and do it, but will have to jackhammer up the floor (removing tiles, etc). It is definitely a tradeoff.

-Peter

[Timber]

Nothing is perfect--i like your idea about the radiant heat-but what about the cost to run the system?

[StressMan79]

AFAIK, the radiant floor consists of

A heater
Servo-controlled Valve manifolds
thermostat(s)
pump
Pex tubing.

I got 900' of pex for 180.00. Thermostats are cheap, and I basically need 1 for starters, maybe $50. The manifolds, heater, and pumjpwill be the wildcard. Maybe $500? Anyway, the whole system will run me under 750. I could get a direct vent for cheaper, but the distributed heat and lack of forced convection is nice too. also, I would eventually like to make a "solar shed" as was posted some time back. RFH will be easy to convert to solar. Not so sure I could convert a forced air system.

Also, I won't be living there next year during any cold spells--I can put in the PEX and wait on the other components. Combining this with the other benefits of RFH, I will be using that.

-Peter

[dvb]

It is funny how this happens all of the time. I am guilty myself! It just shows how you never know where you are going to find useful information in here. I try to read all of the posts - regardless of the title.