Posted By Alton on 09 Feb 2013 08:56 AM
I agree that a pre-stressed or post-tensioned cable should not be damaged.  However, the engineering company can usually advise as to where the cables are located.  Small holes and cutouts are allowed in a slab provided the cables are not damaged.  Beams can contain so many closely spaced cables that it is best to avoid cutting or boring into beams.

That is true but like with my current home which has a post-tension slab, they ended up slightly modifying the cable locations here on the job site and never went back to drawings to modify those. According to the company I spoke to, on the field job site requires some tweaking and changes and they will usually not go back and modify the original drawings since that would get costly and then the city permitting would get involved.

The safest way is to have it sonar/x-ray scanned but that can get costly. Also, the steel tendons do not always run in a straight line so that can throw off the location.

I agree that post-tensioned slabs are not always built according to plans.  Cutting a post-tensioned slab can be risky.

However, the wire strands in pre-stressed, hollow-core planks are factory set and do not get changed in the field.  I mention this because in some areas, pre-stressed hollow-core planks are being used for residential floors and roofs.  One big advantage of hollow-core planks is that shoring is not needed like in shotcrete panels.

I have read the warnings about drilling/cutting post tension cables. Fortunately, the storm shelter doubles as my safe, and I did include 8 empty, 2" counduts around the slab. They go from from a couple utility rooms, a closet and storage room to the outside of the slab. That should allow for running future utilities such as power to a swimming pool pump, landscape lighting, sprinkler system, etc.

The stained glass dome actually goes in the attic level of the tower. It is under cover from the roof above. There are 8 tower windows (arch top double casement) to let light into the tower. The sunlight can then go through a 8' diameter hole in the top / tower level, down to the attic level and the 10' dome. I'll have supplemental lighting behind the stained glass in the attic level for night time and if the natural light is not enough. The tower area is open between the 1st and 2nd floors of the house, so I'll get a good view of the dome from both floors.

This was the best design I could come up with that also allowed easy access to the top of the tower. I wanted to have tower access for the view around the property, lake, etc. I also enjoy watching storms come in, and that should allow a great view of any approaching weather.

I haven't decided yet if I need a protective dome/cover over the stained glass. The concern I have is that air pressure changes in the house, or from opening one of the tower windows might be enough that could damage or move the glass pieces in the dome. I'll probably have a professional install the dome in the tower, and get their opinion at the time. Any input / suggestions from readers here would be welcome as well.

Thanks

So those viewing ports in the tower are actual windows that you can close/lock, correct? If the answer is yes, then you will want some quality windows up there since it is so high off the ground and the home is located in such an open area with no wind breaks. Being that you are in Texas, I assume you may be in the tornado alley portion, so you have to deal with hail storms and wind driven rain at a minimum.

Wind can tunnel through the tower windows and cause some significant pressures against the domed stained glass if you leave a window open.

How are you installing your windows for the rest of the home? Outward flush mounted or interior mounted? The latter gives them better protection from hail.

The tower openings do have glass that I can open/close. It took a while, but I found a company that could do the custom, triple pane, arch top, double casement windows with inward swing that I wanted. The tower windows are wood, but the remainder of the house I am going with vinyl. I had looked into fiberglass, but they just don't make them with the arch top and style I wanted.

I'll talk with my ICF guy and framer about it, but I was thinking I would try to set the windows recessed just a couple inches from the outside, but also have some EIFS type window trim that will give the windows just a little more protection and shade. I am probably going with an acrylic stucco finish for the majority of the exterior wall, except for a natural stone wainscot on the bottom 42". The stone wainscot will hide the dirt, provide more durability than the EIFS (impact and weed-eater protection) and be fire-resistant for any ground level fires (not a big concern, but just a thought).

Are those stained glasses hail resistant? Is it possible for some hail enters from from open window?

I'm sure the stained glass was not designed for hail, and even if it was, I wouldn't want to test it.  I don't plan on keeping tower windows open unless I'm up there.  So I wouldn't expect hail to ever get to the stained glass.  It would have to make it around the 2ft roof overhang, through the triple pane window(s) and then down the hole in the center of the floor on the top level. 

I've lived in Texas almost all my life (36 years), and have never had hail go through house windows.  I'm sure it happens, but not very often with vertically oriented glass.  Car windows are different (no overhang above and more horizontally oriented).

Why would you use 2 different exterior coatings when you can get the benefits (water resistant, fire resistant ) and so much more with StuccoMax, the superior exterior coating for ICF? I have a sample submerged in a bucket of water and been there for 2 months so far and NO difference at all! StuccoMax™ a true one-coat stucco designed to adhere directly to any EPS foam, CMU block, DensGlass, Securock, concrete and other building materials. StuccoMax has been used on ICF construction for its durability, strength, and ease of application allows contractors to “go green” without compromising performance, cost, or simplicity. StuccoMax our exterior wall finish coating performs beyond any conventional exterior stucco in the market today, with excellent water resistance, impact and abrasion resistance as well as resistance to mold and mildew, termite resistant and much more. see www.stuccomax.com for more info

The tower openings do have glass that I can open/close.

Have you considered the cooling and ventilating possibilities/issues with opening windows on a tower of that size? And is the tower ICF all the way up to the ...ah...windows?

ICFHybrid - The tower will be ICF all the way up.  I plan on keeping the tower more of a semi-conditioned space.  It will have a HVAC duct and return, but I don't plan on putting a thermostat up there or keeping it a set temperature.  It does have a lot of glass, and that is why I chose to go with triple pane windows up there.  The remainder of the house will have double pane windows for cost reasons.


Lbear - sorry, I forgot to answer your questions about the ICF reinforcement/PSI.  The engineering called for 3500psi for the walls and 4000psi for the Insul-deck floors.  Wall rebar is mostly #4, spaced 16" vertically and 18" horizontally (to match the forms I'm using).  The engineer did call for #5 vertically, just on the 1st floor level.


ICFCoatings -  I'm not 100% set on the acrylic stucco yet and I know StuccoMax has a couple advantages (stronger and non-combustible), but there are a couple reasons why I am leaning away from it.  Like cement and traditional stucco, as far as I can tell StuccoMax is rigid and non-flexible.  That means I'll probably have to put control joints to allow for thermal changes.  I don't like the appearance of control joints in the longer walls, and I have plenty of those.  The acrylic stucco / EIFS products I have looked at are flexibler enough to go without the control joints. 

Being rigid, StuccoMax does crack.  The sample I ordered arrived with a hairline crack.  You have to stress the sample a little to see the crack, but it is there.  I am concerned that over years and hundreds of freeze/thaw cycles, the hairline cracks may start getting more noticeable.  This may never get to the point where it compromises the coating from a structural/functional standpoint, so my concern is mainly cosmetic.  Again from my reading, the acrylic stucco / EIFS systems have been around for several decades.  Although there are some issues with water intrusion and wood framed structures with EIFS, they have held up well.   I don't think the wood/water intrusion problem will be an issue with ICFs. 

There are plenty of buildings around the Dallas area with Dryvit and other acrylic stucco products to see how they age.  When I asked a StuccoMax rep if there was any buildings in the area I could see with their coating, they pointed me to Houston.  A 4-5 hour road trip is more than I really wanted.

The stone wainscot is also for cosmetic / architectural reasons.  I will use the same Oklahoma sandstone material I used in the retaining walls around the house, and will incorporate it into other outdoor/patio features (swimming pool, outdoor kitchen).  I think it will tie the whole area together better than exclusively using a stucco finish on the house.  Also the stone hides any dirt splashed up by the rain and will reduce any mold/mildew or moisture staining issues that might occur near the ground during wet periods. 

I'd prefer not to turn this thread into a StuccoMax debate, so please message me or contact me by email if you want to discuss further.  Like I said, I'm not 100% decided on the stucco finish yet, so I'm happy to talk about it some more. 

Thanks,

Thomas
[email protected]

Posted By nd96 on 10 Feb 2013 05:49 PM


Lbear - sorry, I forgot to answer your questions about the ICF reinforcement/PSI.  The engineering called for 3500psi for the walls and 4000psi for the Insul-deck floors.  Wall rebar is mostly #4, spaced 16" vertically and 18" horizontally (to match the forms I'm using).  The engineer did call for #5 vertically, just on the 1st floor level.

Don't forget to take good photos of the InsulDeck rebar layout, especially where the InsulDeck ties into & transitions into the ICF walls. 

Are you going with wood window bucks or that vinyl (V-buck)? Are you using treated wood or just regular lumber?

Are you going with wood window bucks or that vinyl (V-buck)? Are you using treated wood or just regular lumber?

I hadn't put much thought into the window bucks.  I think I'd be okay with either treated wood or Vinyl, depends on what my ICF guy typically uses.  I'll ask him next time we talk.  Current estimate looks like about 2-3 month process for all the ICF and decking pours.  I'll be sure to keep the pictures coming. 

Another funny question :
If you use 4" ICF for 2nd floor walls. Then they will be light.
So, Can you build concrete roof with this weight gain.

Posted By theInvincible on 11 Feb 2013 06:49 PM
Another funny question :
If you use 4" ICF for 2nd floor walls. Then they will be light.
So, Can you build concrete roof with this weight gain.

I don't think using 4" ICF would have made a difference with the roof design.  The biggest problem was just engineering the roof the way I wanted in concrete.  Cost and weight were second and 3rd on the list. 

I wouldn't really be interested in going down to 4" ICF.  You really don't save much money, but you do compromise quite a bit of strength.  Sure 4" is probably strong enough for most houses, but 6" is better and easier to consolidate.  But that's just my opinion.

Posted By nd96 on 12 Feb 2013 02:26 PM

I don't think using 4" ICF would have made a difference with the roof design.  The biggest problem was just engineering the roof the way I wanted in concrete.  Cost and weight were second and 3rd on the list. 

I wouldn't really be interested in going down to 4" ICF.  You really don't save much money, but you do compromise quite a bit of strength.  Sure 4" is probably strong enough for most houses, but 6" is better and easier to consolidate.  But that's just my opinion.

Like you mentioned, there really is no substantial savings in concrete when going from 6" to 4" and when going to 4" you end up with more consolidating problems. The absolute minimum structural depth of concrete is 4" and that is assuming 100% consolidation. I've never seen a 4" concrete ICF wall for residential. All the homes I observed were either 6" or 8".

One of your previous post, you said that you can not build concrete roof because your footing piers are not enough to carry the weight.
That's why, I am trying to find a solution to build concrete roof.
Money is allways the last mater for me.

I built a house last year with a stick roof. I am having lots of problems with it now.
1. My trusses are designed in a cheap way. (some parts are not built within trusses)
2. Inspector came and found lots of mistakes. (e.g. number of nails, 4 ft braces for top cord,...)
3. I have to deal with trusses uplift problem.
4. I spent one whole week for installing Raft-R-Made s.
These are the some of them.

If I do this again, I will definitly build a concrete roof.
I MADE A MISTAKE.

I used 18 cubic meter concrete for 8' walls and I used 18 cubic meter concrete for one floor.
So, my ratio is around 1/1. My house is square.
But your house is not square.
I guess your ratio is 1/2.
if you use 4" wall your weight gain will be higher.

I just stumbled across this forum today. Wow, I am so impressed with the information. nd96 I would love to get the name of your builder and where in Dallas you are. My hubby and I are seriously thinking about the Dallas area since we have friends in Corsicanna area. I would love waterfront but think it's just a little too far out of our price range. Which block company did you go with and why? I am sorry for being such a novice but appreciate answers to what seem like stupid questions ; ).

Posted By dancermommd on 14 Feb 2013 10:05 AM
I just stumbled across this forum today. Wow, I am so impressed with the information. nd96 I would love to get the name of your builder and where in Dallas you are. My hubby and I are seriously thinking about the Dallas area since we have friends in Corsicanna area. I would love waterfront but think it's just a little too far out of our price range. Which block company did you go with and why? I am sorry for being such a novice but appreciate answers to what seem like stupid questions ; ).

I'm acting as my own builder.  I've never built a house before, but I've learned enough with my own research over the past 2-3 years, that I am comfortable doing it myself.  So far, I think I've been fortunate with finding good subs, and that is essential if you are going the route I am.  My opinion is that doing your own home design and acting as your own builder is a good way to do a really custom home.  About 80-90% of what I've learned, I found on line. That is part of the reason why I've put up the couple posts on this forum.  Hopefully I can help out someone else out there who might be in the same boat as myself, and to get some input/feedback from the real pros out there.

I'm about 30-40 miles north of Dallas.  I'm just far enough out where land in my area is still pretty reasonable (15-20k/acre), but close enough to the suburbs where it is not a bad commute to work or into town. 

I'm going with Nudura for the house.  That was based mainly on the ICF sub I picked.  Nudura does have its own selling points/advantages.  It is much easier and quicker to put up than the brand I used for the storm shelter.  But once you have your walls up and finished, the brand of block you used is almost inconsequential.  My opinion is use whatever block your builder/ICF sub is most comfortable and familiar with.

ND96 -

I read that taping the top of the ICF block when you do your pour helps keep a clean surface so after you peel the tape off your next row of ICF blocks that you stack and lock neatly without any dried concrete getting in the way.

How will they install the shoring since you have a slab inside already? Would this require them to mount the shoring by running a bolt through the slab?

A laser level will show you that with an ICF wall you can get a true/square wall. I've seen them at 1/8"  - 1/4" square on a long wall section.

Posted By Lbear on 16 Feb 2013 07:39 PM
ND96 -

I read that taping the top of the ICF block when you do your pour helps keep a clean surface so after you peel the tape off your next row of ICF blocks that you stack and lock neatly without any dried concrete getting in the way.

That's why God invented 6" wide duct tape!

How will they install the shoring since you have a slab inside already? Would this require them to mount the shoring by running a bolt through the slab?

From discussions here in the past a lot of that depends on how the floor will be finished. If it's going to be stained concrete then you don't want holes in it. I think some guys use glue. For my garage I put the braces on the outside rather than put holes in the slab.

A laser level will show you that with an ICF wall you can get a true/square wall. I've seen them at 1/8"  - 1/4" square on a long wall section.

You can set squareness and straightness with a tape measure and string! Now level at for the top of the blocks is another story. That depends a lot on the height consistency of the blocks. In my case the corner blocks were taller than the straight blocks and I ended up with 1/2 to 1" variation from the corners to the middle of the wall. On the garage walls I ended up sawing a bit of the top of the inner foam on one wall to bring it the same elevation as the rest of the walls.