Concrete house

[patrick_g]

Our previous (California) house was Spanish Med with red tile roofs, arches, clay pavers and the whole 9 yds. It was built in 1928 and the roof tile was all hand made and had full palm and finger prints of the guy who made it in each tile. We had central heat but no A/C (San Diego on Point Loma) There were few hot humid days where we didn't get enough sea breeze. I don't recall seeing an A/C unit in our area. You didn't have to go far to see them though, especially inland.

Area building traditions are often a response to extant conditions. Then there are folks who want an Alpine ski lodge "A" frame in Phoenix or a sprawling Mexican Hacienda with interior open coutyard (maximum surface exposed to ambient conditions) in St. Paul. You can do it with our modern mechanical systems but you are definitely shoveling sand against the tide. (Or kilowatts against ma nature.)

OK, Paddy... about my panel deck. I liked its ease of use. Ledges were formed in the top of the 12 inch thick basement walls. The panel deck is easy to cut but is shipped cut to all your custom lengths. It rests in the ledge (notch?) we formed by putting a couple 2x4 on top of the forms. The vertical rebar in the wall ran wild (stuck up above the wall just outside of the notch. After the PanelDdeck was placed and the 4x4 shoring system was in place(you can walk on the PanelDeck) Then there are 3 schedules of rebar to place. Our design called for 2 each 1 inch rebar (#8) running in the bottom of the integral beams (14 inch vertical crossection from bottom of beam to top of floor slab) Then up on top of the PanelDeck there is a N-S pattern of rebar. Two sizes were called for there, one size for parallel to the beams and a different size transverse. This mat of rebar was tied together at intersections and a 25:1 or greater overlap on "splices." The 1 inch rebar in the integral beams was heated and bent at right angles to tie to the rebar coming up out of the walls.

Note: There are two lengthwise ribs on opposite sides of rebar. When heating and bending larger rebar like this #8 you do not want a rib on the inside of the radius and on the outside. You want the ribs in the halfway between position OR... the metal will start to separate and the crack will be a stress riser even if you don't massively ruin the rebar and have the end nearly fall off.

After the rebar was placed using wire "chairs" to hold proper spacing (I would recommend NOT DOING THAT and instead recommend using the little concrete spacer blocks with tie wire embedded.) Next the HVAC guys came out and installed the pex loops, securing the Pex atop the rebar with nylon tiewraps.

There was significant difficulty trying to get proper spacing of the pairs of #8 rebar in the bottom of the integral beams. It would be better if the bottom of the beam were wider. The mfg may have changed that since my buy. Not a problem usually as shorter unsuported spans use smaller rebar.

You can walk the Panel Deck to place the rebar. Don't step in the bottom of an integral beam channel. Then when a guy did I just used spray foam to glue the piece back in and no problem. The stuff is easy to work with during the pour since you will be walking on top of the rebar mat. As this was my first large overhead slab poured on shoring (prev was about 8x9 ft) I was thrilled to see the shores worked well and nothing shifted around.

I rented an easily adjusted shoring system that used pairs of vertical 4x4 lumber and an easily adjusted connector.

The next thrill came when I went in the basement under many tons of new ceiling/floor and started taking the shoring out (after a proper period of cure time.) Cement products, unless chemically modified or under unusual conditions, take about 28 days to achieve 90% of their final strentgth. It is a curve, not a straight line but if you treat it as a straight line you will be safe since the actual cure is ahead of a straight line approximatioin.

I felt like one of the Roman architects of arches that tradition tells us stood under an arch as the scaffold was removed so that if the arch failed the architect would be removed from the brotherhood of arch designers and therefore improve the average skill level. (Sort of a precursor to the Darwin Awards.)

I collaborated with a Mech Eng on the design of the penetration for the stairs and a beam in the ceiling to reduce the max span of the PanelDeck. Hiring the PE got a PE stamp on the design and access to her E&O insurance if there had been a problem. If there is ever an insurance issue, it is good to have a PE stamp on your plans. It shows you exercised due dilligence and aren't negligent.

NOTE: At no time in the entire building process did any inspector ever come on the property. I took out exactly one permit (sort of) and that was done some years before we broke ground. That was when we registered a perk test for the septic system with the Department of Environmental Quality when I got a 2fer with the civil eng who perked my mom's house because I helped him operate the two man auger.

I insisted on only lisc electricians and plumbers and that all trades work to code or better. When in doubt or when I wanted a PE stamp I hired a PE who would moonlight for some extra $. You don't need to know everything the specialist knows. You need to know enough to know that they know. I was very pleased with the 3 engineers I used. A soils engineering consultant, a civil eng, and a mechanical eng. Money well spent if for no other reason than peace of mind but the PE stamp on the plans is a nice to have.

Paddy, I hope I didn't forget something. Don't be bashful, ask anything. I may not know or recall the answer but I will try.

I'm still not finished with my new house. My latest project was cutting porcelain tile with my new (on sale at HF) tile saw to tile some of the upstairs window sills. I did 3 of them in my "spare time" in last two days. I make custom oak trim to cover the joint between the tile and the wall's sheetrock. A few rips, a couple passes with a router, funny cuts with miter saw and then sanding, staining, clear coating, and shoot with brad nailer. I love it when I can actually do it and not have it look like I did it.d (I'm not world class woodworker but I try.)

Tried my hand at adjusting the flow controls of some of the hydronics to get a better ballance of heat distribution and a warmer shower wall and floor. Cut a hoile in the ceiling and roof of the garden/sun room and installed a cast iron decorative parlor stove (has mineral glass in front and fake logs so you can watch the fire) Now if it will get cold again we can fire it up and have a breakfast or supper in there to see the sunrise or sunset. The room has central heat and air and is its own thermostatically controlled zone but a little propane gas log parlor stove is neater. No one ever got much pleasure out of watching a hot air register.

Pat

Pat

 

[Paddy]

Eddie,

The "feel" is an important issue. I have been in rooms that have an echo with reverberations such that you can't here yourself think! I also have been in others that feel very nice. Empty rooms are the worst. Wood and fabric eliminate the sound issue. for example a nice oriental rug and wood furnture. Even a stick built home feels odd until there are homey items in side.

 

[Paddy]

Hoping to start this coming spring. The floor plan has been left untill we have confirmed the wall/floor system will fly. Over the last few months, I have seen enough examples on the net that I feel 100% confident the wall sandwitch system will work. The design now grows around the construction capability. Example: With going with concrete, I will have a flat roof with 3-4' half walls for usability. Nice roof top patio with great views to the lake. If I had gone with stick frame, a tradional roof would be needed. I have sketched a few plans but the real chalenge will be to get in sync with the wife's ideas!

 

[patrick_g]

Paddy, I roger the comments regarding reverberation and acoustical treatment for same. I knew when I designed my house from the dimensions and other considerations that I would probably have a reverb problem (it hadn't been that many decades since I took an upper div acoustics class in physics curriculum.) As was stated, things get nicer after you put in the furnishings and soft stuff. Since I went with porcelain tile in the great room and the cathedral ceiling nearly 30 ft up with 12:12 ceilings, I defered floor coverings in the loft to see just how "live" the great room would be with furnishings. I wanted to see if I could use hard flooring upstairs in the areas open to the great room or if I would have to go with carpet.

The carpet will be installed early in the new year. In theory the sound will bounce down off the ceiling and be caught by the carpet and not reflected. I had thought I might need extra "help"... well I'm shopping for tapestries to hang out a few inches from the end walls so the sound will make two passes through the material. Tapestries can get darned expensive. I'm hoping I don't have to run lines parallel with the roof ridge to hang midieval banners for further quieting.

The basement doesn't seem as live as the great room. The ceilings down there are a tad over 9 ft. When I wainscot the walls up about 4 ft with slabs (probably bark-on) of native (eastern red) cedar (AKA Juniper or aromatic cedar) and glue the carpeting from the chair rail to the ceiling I expect not to have to give it any other acoustical treatment. I had allowed for how I might have had to do an acoustical treatment to the basement ceiling but it doesn't seem like it will come close to needing that. Since much of the basement floor is slab and the acoustics are OK, I have the option to tile the rest but am leaning toward indoor outdoor carpet (undecided.)

The basement is not under all the house, just somewhat over 1000 sq ft in the middle. It is a walkout basement with 6 ft double 3-0 sliding doors and sidelights and double hung windows so it isn't dark nor does it cause any slightly claustrophobic friends any problems. It just doesn't seem all that much like a basement. There is a guest bedroom there (it is a safe room with steel shutters on the inside for covering the window.) There is a smaller kitchen in the basement to support patio cookouts (and not trudge up and down the stairs over and over.) Of course there is a full bath. There is a paved patio with a roof which is the floor of the back porch above.

Even self proclaimed basement haters don't mind this basement. I'll like it a lot better when the tournament size pool table is installed. The big double slider makes getting furnishings (think POOL TABLE and recliner to fall asleep in while watching the gas log.

All the mechanicals of the geo heatpump and the hydronic system are in an equipment space in the basement behind doors and an insulated wall so the noise is not bad and it is all out of sight. All the doors in the house but one closet door are a minimum of 3-0.

Thinking ahead about aging I investigated elevators and had some prelim designs that saved a space to install one. Interesting.. like you can buy 200 amp breaker boxes for about $100 and up but a 400 amp box runs $1200-$1500 and up. A two floor elevator is not so bad but a 3 floor is out of sight compared to what I was willing to consider. Four floor elevastors wold be a mint. All I had to do was design with all straight run stairs with no intermediate landings and make the stairs wide enough for comfortable passing. This permits a chair lift to be retrofitted on each of the two runs of stairs should it ever become neccessary.

There are DC systems available that run on a battery which is charged automatically. These of course will support many runs during a power failure before the batt is flat. None of us may ever need such equpment but all I had to sacrifice was a curved staircase which I didn't really want anyway.

With a basement and three floors, these may be considerations for you if you plan on staying in this house "forever."

With the expected wall performance of the encapsulated and thermally isolated insulation, besides being able to heat the house with a candle and cool it with an icecube, the virtually non existance of infiltration of at least an order of magnitude under the typical new stick construction will require you to use mechanical ventilation. Whether you would be better served by an ERV or a HRV will likely depend on your climate, especially humidity control considerations. It was a wash for us. The gains to be had cost enough to take the breakeven out to about the estimated lifetime of the unit so we skipped the humidity handling and went with the plain air to air heat exchanger with multi-speed fan controlled by a humidistat in the master bath.

We did not install heat or A/C in the walk-in closets (ICF portion of the house) just an exhaust grill "Yed" to the exhaust grills above the Jacuzzi, toilet, and shower. These exhaust grills are where the "used/stale" air is removed from the house. The fresh air to replace the stale comes into the the rest of the house not the master suite. The air that drifts through the master suite to get to the exhausts in the closets and the bath is conditioned air so no need to have ducts to deliver A/C or heat and no need for radiant. The closet is carpeted so no cold floor. The master bath has hydronic tile floors. The shower has heated walls and floor and hydronic towel warmers. The floor and walls of the shower have their own programable thermostat and the towel warmer is in series with the rest and doesn't need a control.

A shower raises the humidity and the humidistat next to the entry to the doorless curtainless shower senses that and speeds up the ventilator. If the RH in the exhaust duct exceeds an adjustable threshold on a humidistat in the exhaust duct such as when we take back to back showers on maybe a humid day then there is a booster fan that comes on and really gets with the program exhausting air till its humidistat is satisfied.

The booster fan doesn't run very often and doesn't run very long after the source of the extra humidity is secured. You can hear it but it certainly is not objectionable. The regular ventilator fan is virtually impossible to hear anywhere in the house except in the tea room attic where the unit is mounted. When the ventilator is on its highest speed (but not booster fan) and there is nothing making noise anywhere in the hoiuse and I have my hearing aids in, you can just barely hear the air coming out of the supply register high in the great room. If you don't make a point of listening for it yoiu would never know it was running.

For a tight house as you will want you will need a good fresh air supply to avoid the "sick house syndrome" as there are just too many emitters of formaldehyde and other BAD things.

I tried to remote most of the exhaust fans as a noise control issue. I designed my range hoods. I use two blowers. One is mounted in the "attic" above the front porch ceiling, to supply makeup air to replace what I exhaust with the other one which is mounted on top of the roof. It uses an "air curtain" to separate the volume of air above the stove top from the rest of the house. I supply unconditioined air to this space with a variable blower. This air is "sacrificed" when the exhaust blower sucks out heat and odors. Since I wanted a high volume exhaust fan I didn't want to pull a vacuum on the house or throw away all the expensively conditioned air. Incidently, I bought my hood filters from the parts dept at Sears so replacements are pretty assured.

The master bath of course has no traditional "fart fan" as it has 3 exhaust ducts that run 24-7. I used appropriately rated remoted duct fans for bathroom exhaust fans so the noise factor was reduced bunches. One downside is since guests can't hear it they forget to turn it off. I will retrofit timer switches or motion detectors to turn the fans on till x number of minutes after no motiion is detected. I'm leaning toward the latter.

When you do your hydronics, consider hydronic ceilings in the bedroom. It works great and is not interfered with by furniture. If you lay out across a bed with hydronic floors you get no IR but with a radiant ceiling you do. The IR easily heats the carpet so there is no cold floor syndrome.

Interesting comment... I have been in rooms that have an echo with reverberations such that you can't here yourself think!

At the lab I worked at in San Diego there was a new bld that had received various design awards. It was virtually impossible to talk in the stairwells. The stairwells were easily a 4-5 second space. I could not imagine being in those stairwells during a simulated or for real building evacuation with all the shouting. It would make the tower of Babel sceanario seem like perfect comms. As a Gov lab we were target of simulated terrorist drills so building evacs were not uncommon.

Patrick_g

 

[40Kchicks]

Paddy

Being that my ICF structures were poultry barns the interior is sheeted with plastic and the exterior is covered with metal steel siding. Concrete interiors and exteriors would have been great and eliminated a couple steps in my construction but doing forms for that size of structure would have took a lot of time and been very expensive.

When we do our house the interior will be drywall and the exterior will be most likely hardy plank.

Eric

 

[Paddy]

Patrick G,

Clearification; Three total floors of living space. That includes the walk out basement. The upper most flat roof, can/will act as an outdoor patio.

I have read through your project on CountryByNet.com :: The Country Life Community in the home building section. Fun read and you did a supurb job documenting all the steps. I hope to do half as a good job!

You are correct, with a tight house I will need to use heat exchangers to introduce fresh air. Funny though, I read some where if you have a dog and dog door, you may be able to skip that part! I work out of the home and my Jack Russel comes and goes more often than one can imagine.

Presure balance. Even in my current home, I installed an outside air intake to balance the use of the fireplace. Doors and windows would whissel otherwise.




Patrick

 

[sandman2234]

Just a thought about running string for future wiring pulls.
Most strings will degrade over time. Just what you don't want, get a pull started and the pulling string breaks, just far enough in that you can't get ahold of it.
As expensive as it is, probably the best thing for long term is stainless steel safey wire. Not cheap, but you can pull a lot of weight with it and that matters, 40 or 50 years later when you decide to upgrade a circuit. It does come in rolls large enough to handle a long run, so give it some thought when you start pulling wires.
David from jax

 

[dfkrug]

I think the reason we don't see concrete construction here is because when homes were first built in the US, wood was king. We as a nation have just kept doing that way. I travel quite a bit and the US appears to be the only place where wood homes dominate the market. Patrick

Yes, wood is a traditional building material in the US. It was and is abundent
and is perceived as cheap, too. Densely populated areas like Europe did
not always have the same abundence of wood. Another reason that wood
is not seen as a viable building material for houses is government regulation. There are countries and cities (Europe again) where building out of wood
is not allowed due to fire danger. Imagine if YOUR house was only inches
from your neighbors' and you both were chain smokers. Not to mention
the noise....

Everyone who wants a house built of better materials for fire resistance,
termite resistance, earthquake resistance, storm resistance, and lower
energy use must go out and research the alternatives. Then s/he must
find a builder to use that method, or DIY. What builder is going to choose
anything but stick framing unless he is forced to? All those benefits
go to the owner. He only get the risks of using something he is not efficient
with.

As for the "ideal" building envelope, there are always trade-offs with costs
and compromises in other areas. The best for one criterion is not the
best for another. Why ICFs are so good is that they provide very high
benefits with fairly low cost impact.

 

[NY_Yankees_Fan]

I do not want to dampen your excitement of the new home, but I just see things a little different being on the fire protection side of the business for many years. With a little planning towards fire protection you will have a well fire protected home too.

Everything burns, just at different rates.

The walls may not be combustible BUT unless all the furniture will be made out of concrete the combustible load inside a typical home is high. You are building the home to be energy efficient and tight, great to save energy, but bad for fighting a fire. The fire department will have a difficult time getting into the house since it will be like fighting a fire inside of an oven. No please for the heat and smoke to go. If they can not get in they can not get you and your family out!

You may want to consider the installation of an automatic fire sprinkler system in your new home. A tank with 200-300 gallons of water connected to pipes is all you need to provide a proven technology that will save life and property. The type of construction you are using will make the instillation more difficult , but something to consider. See the link below my name for more information about home fire sprinkler systems. Exposed pipe may add interest and will make the installation easier, although not all people like the exposed pipe look.

If you do not install a fire sprinkler system consider installing a complete fire detection system tied to a central station. The fire detection system will provide early notification to the FD so you will not have to wait for the neighbor to see the smoke to call the FD. Use a dual sensor smoke detector which has both ionization and photoelectric detection. This will cover both slow and fast burning fires and provide early notification of a fire to you and the family.

Also consider buying 100% replacement cost insurance on the home and contents. Your construction methods will not fit the cookie cutter insurance policy. Make sure the insurance company knows what they have and what it takes to replace the structure. A fire will most likely result in the total loss of contents with structural damage. Hot concrete and fire hoses result in cracks and reduce the structural strength.

 

[Paddy]

NY,

I have considered a sprikler system and I think there are great idea. I don't think I will have too much trouble keeping the plumbing hidden in the ceilings. The foam form floor systems have large hollow chanels left for utilities.

I won't have wall to wall carpet so that will take a large load of toxic material out.

How much does it cost for a sprinkler head? Can they be bought by my plumber?

Thanks for the reminder