Is post-tension better than rebar? Concrete foundation - Texas Barndominiums Episode 29
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- Опубліковано 23 тра 2018
- I have been doing research for a long time about the difference between post-tension foundations vs rebar foundations. I have not found a definitive answer so I decided to go out and find out for myself which is better in order to get less surface cracking. The latest price increases in rebar made me realize it was time to find out. If we can get the same or better quality and save some money that we can pass on to our customers, it's a win-win situation.
(Update 7.19.18: Post tension foundations cost about the same, and in some instances, more than rebar due to the extra steps needed after foundation has been poured. Pre-tension tendons, post tension tendons, inspection, cut cables, plaster foundation. Extra trips and extra labor offset the small savings obtained from using tendons over rebar. However, we are indeed experiencing less cracking with post tension, so we will keep using it)
Rebar is "Old School". It has worked for a long time and it still works. But post-tension also works, and some say it works even better. Post tension uses steel tendons that will be tightened after the foundation has had time to cure. Many say it's better because hairline cracks will not form as easily. Some say it doesn't matter, and concrete will crack either way. We have decided to do two or three slabs in post tension and we will keep track of how they perform vs. rebar. We will keep you updated.
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Excellent job explaining why you are trying this way. It is nice watching quality work.
Thank you for the quality videos. They are very informative, and you obviously care tremendously about your final product. Thank you.
Tom, UA-cam just showed me your comments!
I think you for your kind words... one year later... wow.
so it's been two years since this post tension, what was your final thought on post tension and cracking?
I've never heard of this type. I've only heard of reber!. Thank you, I learned something today!
Stick with epoxy coated rebar. Bridges and highways don't use pt.
Good job, Thank you for your information.
esta chingon el jale,cable de tencion,nosotros usamos idrualiko para estirar el cable...
I just can’t imagine that the compression provided by the cables really disperses across an entire slab. On the outer edges sure, and there’s often load bearing there but is it worth the extra work and cost… not sure yet. New Englander who has never seen this before and is trying to learn more
Curing is the key/ Giatek 3 sensor for psi strength
Rebar, no worries about post tensioning tendons failing...
As none exist...
Also, you find a post tensioning that guarantees their work for the amount of life cycle claim and I will be surprised...
Use them and make sure they bond that statement if they make that claim...
Otherwise, just add the steel...
Ummm. Yeah ok.
How did it turn out? Also, can you drill it? For anchoring.
How did you like this, are the better for texas, or will you still need foundation leveling later in life?
Neat. Have you given any thought to 'Helix microrebar'? Small, galvanized steel coils tossed into the mixing truck much like fiberglass fiber - however they are always under tension (unlike rebar) and in a omnidirectional load path you get less cracking. Meets ACI code and can eliminate most rebar for slabs. Literally designed to be 'bomb proof concrete' and used in runways/hangars. Worth looking into, if only for the reduced rebar/labor angle.
[note: never used in personally, but plan to]
do they solve the rebar rust issue?
What’s your opinion on galvanized wire cable in bridge columns verses rebar
Depending on the native soil with it's reactions to moisture expansion and contraction an engineer will decide what is better to use .I pour concrete for almost 20 years and we do way more rebar slabs then p t slabs .I think probly because rebar is a easier and more of a tried and true method
I would think that a combination of both would be the best way, and perhaps the most cost effective. Reinforcing could be wire wire mesh near the top of the slab. People should know there is a difference between placing concrete and pouring it. Pouring being the slump is very wet to make it easier to work but the strength is much lower than the design being it has too much water.
I like this guy.
One of the big problems is if the owner drills to install something like a car lift and damage the post tension cable you can have a big problem.
I’m building a house where the builder needs to cut the slab to do an electrical conduit to the kitchen island. This video helped me feel better about my rebar slab
Only a problem if you're dumb. Know where the cables run and don't drill into them.
@@smokestrong1000 Not true, how would a guy that comes to the house to do some plumbing know when the owner doesn't tell him, "hey, this house has post tensioned support", when the new owner of the house doesn't even know?
@@mikemurphy7519 that's the home owner again being dumb. That's their responsibility to know how their house was built. A drive down to the citys office will have all the records of the blue prints of the house and information on it including the permitting process of the foundation. If you're going to drill into your foundation without doing that then that's your fault.
So what do you think today post tension or rebar?
I pull forms same day on post tention I don't use nails on the anchors we tie the ends with wire on the outside of the form and cut the wire and pull the forms same day and do a beam final
PS: very cool aerial drone shots!
Thank you. Daniel did a good job.
If you switch to post tension you should add steel fiber as well as the fiber is more for cracking and cover and keep the cover wet 7 to 10 days tie to the tension cable monitors so you can read that slab has come up to strength in real time good luck
Rebar with Euclid tuff strand fibers with eclipse concrete additive.
Awesome!!!
Do you guys build in Florida?
At my work they use both.. you think that’s a waste of material ?
I've heard alot engineers complain about the post tension...and if you buy a new house with post tensioning alot of companies only guarantee the slab cracking or problems with the slab for 10 years. Rebar will eventually rust and crack but has been around forever....I would like to see a slab made of a fiber glass , plastic mix......fiber glass being very durable strong, and plastic will last forever.
Don't the cables have to be somewhat straight before the pour ?
Those looked loose with some slightly curved up and others curved down ?
The PT cables will hang down into the grade beams to help reinforce it. The straightness of the cables is irrelevant. PT cables work by squeezing the concrete together at incredible strength. Thats why it will cause less cracking and allow the concrete to be more flexible for ground movement as well. Its a very neat system; we use it on all of our projects building apartments.
How think is that concrete pad and what's the cost to have a foundation that size done?
6in 160 per yard x100 yard 16000.00
How about pre-tensioned concrete?
Sir,
What are the accessories of SOG PT tendons
And how to find accessories qty
Anybody tell me
Post tension is garbage. Another way to cut corners. Entire condo unit has cracked foundation and cracking stucco and sinking. Lennar thought it'd be a good idea to use this method and now the homeowners are paying for it.
Do you guys also find the land for the house? like a complete package or I have to buy the land separate ?
Separate
How is it that in Florida--which probably has more slab buildings than the rest of the USA combined (not to mention the strictest hurricane-resistant building codes)--slabs are poured with NO rebar, only welded-wire-mesh, and they go uncracked for decades. Sure, the surrounding footer has lots of rebar, but the vast area of the slab itself is just WWM, propped up on "chairs" over the visqueen vapor barrier, and total concrete thickness no more than 5-6 inches... is it that the sandy soil provides more support?
Sand doesn’t expand and contract with moisture like clay does.
I had a Jim Walter house built in North Florida on what is essentially 10,000 yo sand dunes. #5 rebar in the whole foundation (which is all footers, no slab) back in 2008.
Any plans to add rain water harvesting to your builds ?
Yes, we have done a few.
Practical system safe time and codt
2:30 pulling forms on the same day or next day is a mistake, leave it for 72 hours for max strength!
How do you form your porch so you can pour main floor and porch together?
I have many videos on pouring concrete. Check them out and you’ll see how we do it.
The short answer is we form the perimeter of the concrete, then put more forms inside which are to separate home from porches. We pull those forms off while pouring as soon as concrete is stiff enough. We then pour the porches.
@@TexasBarndominiums that's how I done as well already. Just thought you might have a better way. Lol
That's a vera nice
I personally dislike post tension. If ever a need arises to dig through the slab, cutting the steel, post tension loses its value.
My home is built in 2013 on post-tension already have a 1/16 inch crack that goes across the house in the 2nd year... This evidence has proven that this technology isn't working.
Yea rebar is better they are doing this just to save money.
Overengineering is not such a bad thing. Maybe they will want to turn the building into a discotheque for elephants someday:)
😂
they used this on my foundation,they left these little bricks behind that i don’t know what they are used for
They are called “chairs”, and they are used to make sure cables or rebar are not sitting on the ground when pouring.
👷🏻♂️ Casa primo 😂⛈
So when the maintenance guy or owner drills into the slab.. what about those cables?
TurboFlush they untension, rapidly, lol.
You hit one and it goes bang and your fucked
Must be Austin tx
By pulling forms off same by or next day reduces the strength and life of the concrete by some 20%. Suggest you work with a P.E. who actually knows facts and data. The whole concrete pour and strip industry is flawed. Proper engineering includes a 100% safety factor. That is not 'over engineering'.
Rebar is better.
Can you please explain how?
@@TexasBarndominiums try the 6.5 prc lots of post tension
Not on texas clay! Maybe in LA.