Quality House Foundations: Avoid Structural Problems
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- เผยแพร่เมื่อ 22 ธ.ค. 2024
- What type of house foundation engineering is necessary to avoid structural issues and water problems in your basement? Here we look at some best practices when building a new home with a basement. This is the first of a three part series on house foundations. Be sure to check out the other two foundation videos below...
• Avoiding Basement Wate... Avoiding Basement Water Leaks
• House Foundation Soil ... House Foundation Soil Bearing Capacity: Avoid Structural Issues
Gotta love all the armchair builders!!!! Advising this professional!!!! Tonto!!!!
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
Two comments:
1. If you wish to finish the basement, consider the fact that heating ducts will run below the floor joists, subtracting about 10” in height. If you want a true main level room feel in your finished basement, you should consider 10 foot, not 9 foot basement walls to have an 8+ foot finished basement ceiling. This also makes running and maintaining utilities in the basement ceiling easier, as you can avoid drilling through your floor joists. I have had electricians severly compromise joist strength by drilling for electrical cable passage too close to the bottom of joists.
2. Not shown here, but I saw you waterproof and insulate in your 64-day build video. The bitumous coating on the exterior is traditional, but also traditionally a waterproofing failure point. There are dimpled plastic flexible sheeting membranes that can be applied over top ofthe insulation and OVER the french drain system. This creates a much more effective waterproofing since it is unaffected by cracking walls, protects the french drain from silting up, and also protect the integrity of the of the exterior insulation.
My recommendations make the foundation slightly more expensive, but as you say, the foundation is the base on which the rest of the build rests.
what state are you in?
We did this often in GA, but never dropped it below the flooring above, open truss systems are much better in reference to ducting, plumbing, and electrical.
Good info and need to inc into my build since where i live now that has all happened to the foundation and I’m on top of bluff.
@@louismccall That’s a good alternative if you don’t mind the extra springiness in the floor. What do you do if the main heating/AC supply ducts run perpendicular to the floor trusses?
12 foot basement it is! Thanks!
I’m a noob but I thought this was really informative. Good stuff
SAME
Is it possible to built 200 sq. m. and 150 Sq. m. Ground floor and same built in areas of 2 more upper floors, and what structural aspects needs to be considered and advise me if there is a design or requirement showing the minimum requirement (rebar, thickness of shear wall ....) and is it possible to construct the slab of the basement with cyclopean concrete instead of using heavily reinforced RC Concrete?
Nice video. I like that you included the IRC's and the rebar grades. My preference for these poured foundations is to also install a perimeter drain tile over gravel to transport leached runoff. Let's keep the basement dry. (also either painted on, or rubber membrane).
Do you have any video on Complete House Construction from foundation till Roof
3:40 "that black chair holds the rebar 2...3 inches off the ground, which gives it maximum support"
What do you mean with support? Why is it a maximum at 2...3 inches?
Recommend editing to specify the reinforcement you showed does not help mitigate flexural cracking due to settlement. You need bars on TOP of the footing, 1.5”-2” from top in order to provide tensile resistance and prevent concrete footing from cracking due to possible settlement.
Overall great overview of foundation! :-)
Thanks for commenting. The typical spread footing has continuous bearing underneath along the length of the footing. We’re most concerned about possible small pockets of soil below that may settle. When this happens, that section of footing will want to fall into the void below. This puts the concrete into compression at the top of the footing and tension in the bottom. And because concrete is strong on compressive strength and weak in tension, we place the rebar in the lower portion of the footing.
@@OpenBookBuild At the 4 min mark in video you show a cross section with bars in the bottom, then at the 4:12 mark you show footing cantilevered. Bars are needed in the top as well in this scenario of failure due to the cantilever, the forces are swapped in this section, tensile top and compression bottom.
Also, overall great video, simply detailed and explains real well the requirements and importance of footings/foundations. Most home owners have no idea the importance of foundations.
@@mellis6888 For the typical residential home we want the rebar in the lower portion of the footing. The International Residential Code has it here for the reasons I mentioned above. The most likely case under a continuous home footing is for small, localized pockets of soil to settle causing the footing in that location to want to settle as well. This puts the top of the footing in compression and bottom in tension. My video is supposed to show this situation...although I can totally see how you would interpret it otherwise. But don't let my bad art skills send the wrong message...the rebar goes in the bottom portion of the footing in most cases. We want to avoid a cantilevered footing...this will most likely lead to structural failure.
@@mellis6888 No one can predict where the settlement will occur-if you could then you would excavate or compact the areas with poor bearing before pouring the footing. Footing design assumes proper soil bearing. If soil bearing is unreliable then grade beams are specified. Standard practice is to put rebar 2" above the ground.
I thought it was meant to be in the top 3rd of the slab?
Very helpful and informative video. Thank you so much for taking your time and creating this with high quality.
Everyone should follow that practice, but the inspectors generally don't babysit builders in every step.
If the basement wall is designed as a retaining wall the floor attachment should not matter, but that means waiting 4 weeks for the concrete to reach design strength. Even with a retaining wall design, engineers have specified to pour the basement slab before backfilling to keep the wall from moving. I am a little skeptical about a 10" x 60" x 30' footing with four #5 bars moving anywhere, but I obey my orders anyway. Mostly.
Hi, great video. need some advise. build a house in Ghana many years ago, its a split level into the side of a steep hill, having a lot of damp problem on the groundfloor, any solutions?
Is it normal for water to build up like that when you place a foundation? Wouldnt that pose an issue later on?
A very beautiful and benefitial channel , but I wish you would display the units of measurments in mks system. I would be very pleasant if you do so .I can't well estimate quantities with the british system.
The distance of the vertical and horizontal rebars of the wall is it in accordance to building codes/standard.
wow. this “foundation “ is incredibly minimal. cant believe that’s all the rebar required. i’ve been a iron worker for about 26 yrs. i’ve never see. a basement foundation with almost no rebar. 1 curtain #6 at 36” on center vertical . we have 2 curtains #8 @ 6” on center with # 6 horizontal bars at 8” on center on both layers ( curtains ) 3 # 5 in a footing. wow. we mostly do raft slabs. no footings. just a slab that is 24”-36” thick with #7 and the bottom layer at 6” on center with #5 top layer at 16” oc. this foundation as far as rebar is concerned would take my crew one day to tie in. we usually get around one ton (2,000 lbs ) put in for each guy. doesn’t look like there is much more than 3 ton. i should mention i live in california. a basement like this out here has a minimum of 20 tons of rebar. i just finished one on coronado island. that foundation had 53 TONS of rebar and almost 26,000 ft of post tension cable. thats just the slab. the wall’s supporting this slab had another 12 tons of rebar. i wish i could post some pictures of
Is it ok if you don't have any anchor bolts sticking out from the top of your foundation walls? All I have are these long metal pieces bent at 90-degree angles, but no bolts anywhere. This is for a 3-story home, framing should start next week. The basement foundation walls are 8-ft tall.
I know I'm a little late on this, but I've been turned on to the Superior Wall system. Some builders swear by them, others avoid them. The part I'm most curious about is there is no footing for these foundation walls. I think this is what alarms most builders. But I talked to the local sales rep who said in the past 10 years he's supervised the installation of at least 70 foundations and there have been no call backs for them. I'd like to know what you think about this system.
Getting no call backs is a not a particularly strong argument... Look at surfside building, it was under design on at least 3 critical elements and was standing for 40 years. Any extreme events would have knock it down. The fact that in 10 years (which is very small in comparison with the average age of buildings and structural knowledge) there was no "call backs" is a stupid argument. Did someone with knowledge went on site to validate that everything is performing correctly after 10 years?
Anyway. I went on Superior Wall website. It's a prefabricated foundation system, nothing fancy. It's probably somewhat superior to a CMU foundation wall, but comes with the same problems: dealing with the joints. I believe they have special connectors at each panel ends. You should read the manual if you want to select this system at one point, its pretty well detailed. I would be careful depending on the type of soil you are on, but they have tables saying the same thing. Usually, a residential foundation wall is way overkill in terms of amount of concrete for the amount of loading provided (concrete tension capacity alone is sufficient in most cases). To my knowledge, it has been historically like that because it required less specialized work force, less specialized plans and gave extra capacity (longevity) to the building. Note that the thicknesses of a prefab panel will probably be a lot closer to the actual capacity needed, which means that in 20 years, when you want to make a modification... good luck!
In all cases, most of your questions would be answered if you just read the manual on their website.
I don't think anybody avoid Superior walls except for the price. They're absolutely excellent
@@EarendilTheBlessed sigh* Is it possible for anyone to reply to a comment one without throwing insults? I'm just learning how about the product and relayed what the rep told me. I don't think we have a building practice that lasts these days. It's far too expensive.
@@MsBridgesSocial
I believe I was not throwing insults. Don't take it that way. I am having the same kind of conversation with my partners regarding this "no call backs". If it's a bad design, it's a bad design and it will show at some point. Anyway, it was just a note on that particular phrase. The rest of my comment should have helped you.
I know that it has been several months since you posted this but I would suggest checking out Steve Basseck Architect and Matt Rissinger. Both have talked about Superior walls on more than 1 occasion. That might also be some info on Matt’s Build Show Network discussing Superior wall. Pretty much every foundation system is going to have its pros and cons, you just need to choose what works best for you and the area you are building.
What are you thoughts on Superior Wall pre-fab foundations?
👍👍👍 I’d like to look at the second part of the video please
thank you so much for the details and short video
That rebar would not protect in the scenario you gave where you have erosion or settlement on the end, though the reinforcement in the wall would help resist that to a point. The tension side of the footing in that particular case would be at the top, thus you would need rebar at the top to resist that or cracking will occur. Rebar at the bottom is only going to resist positive bending moments, which will usually occur in cases where erosion/settlement takes place towards the middle of the beam. True best practice in this case would be double reinforcement where you have rebar 1.5" down from the top and 1.5" up from the bottom. Most of the time it is not needed though since it is quite rare to have a case where erosion or settlement happens at the end of a foundation, unless it's built on a very steep slope. Having said that, this foundation looks wonderfully built and assuming the soil conditions are fairly stable i'm sure it will live past the life expectancy of the home.
My thoughts too on the rebar placement in a soil void scenario. Tension on top compression on bottom. The bottom rebar is useless in that scenario
Well if we are talking beat practices then should there be compacted gravel beneath the footing?
Virgin ground is perfect. In most cases there’s no need to put stone under a footing unless the excavation was dug too deep or if poor soils were encountered.
When do you need forms for footers? I've seem many of them poured to desired depth and width below grade after which either formed walls or cement block is added on top of them. Thanks
You mention possible problems. Why do you not do something from square one to avoid known possible problems. What's wrong with "over-kill" measures. Or commercial/architectural grade standards applied to CHEAP residential standards.
Future proof conduit from the outside in?
How much is all that?
Excellent tutorial ! Well done , loved your voice !
5:25 are you using inside or outside water proofing solution?
What are the dimensions of the footing?
On your video about basement did you added the concrete you said that total cost was $25300
Great video. So informative! Much appreciated. 😎
Is it better to use blocks or just concrete for the foundation?
Concrete
Solid concrete is higher quality. Blocks ar e the norm in my area. You can also pour concrete and put rebar inside concrete blocks. Concrete blocks are acceptable at least in my area but poured is higher quality for sure.
In my area most people are more familiar with the block so a small minority of houses have poured. This includes expensive custom builders by the way; most are using block.
blocks are a much, much better value (10-20x), basically either you do poured or blocks purely but absolutely take advantage of the fact blocks are so cheap somehow, (3$ for 100lb shipped in bulk) solid is obviously stronger but the value is just awful because you can never replicate what a multi megawatt machine does with a pouring truck.
is basement must be casted in one solid mass or it can be casted layer by layer. like isnot 9' concrete wall but 9 x 1' concrete wall, and can it use wire mesh rebar instead vertical mesh rebar?
I super love your content man! Very impressed! I will join your website in a couple of months.
Seeing the workman standing in water tells me site prep was not done correctly. Should be gravel, drainage piping, compaction, plastic sheeting, sump pump before any concrete is placed.
Also, where was the vertical rebar connecting the footing to the wall through the cold joint?
WHY NOT MAKE IT 12Ft in height and 12in thick and also build a French drain with a sup pump so no water can go inside the basement??????
2018 IBC requires only 2 sets of #4 rebar.
Good Day 👍🙏.. Just wondering, pouring concrete directly on soil ( regardless if its levelled - compacted or not ) without any waterproofing material / pvc sheet will result in reduction in water content of the Concrete. Soil will readily absorb water from the concrete. As a result composition of the Concrete will be affected; which in turn will affect concrete strength.
Footing could do better with 6 Rebars which are tied in place using Lateral Ties.
If possible do add a video of the Completed Project.
Wishing everyone Merry X'mas..🎉
Sushil Adhikari.
( India )
Can you do away with the rebar using Helix steel?
Alejandro Vanags that’s a good question. I really like the idea. I know the rebar connecting the footing to the Poured wall needs to be there even with helix. And based on the Helix literature I’m not certain it will provide the appropriate tensile strength in the below grade basement wall. There are tremendous lateral forces on a basement wall when the soil gets saturated.
Why more psi on walls than footing
great informative video!
Here rebar shouldn't be placed more than 4 inches from edge of concrete. Because rust belt.
Framing should be done before back filling.
Agreed, at least the floor.
Subscribed! Great channel
Always gravel under concrete. My uncle always said "concrete doesn't like wet feet"
Great teaching Thank You Man.🕋
Simply raise the footing to the height of the boards and level the board. It wouldn't be that much extra.
Surprised that they're not vibrating that concrete when pouring... I would expect a lot of voids if not vibrated.
I was surprised too, he only had a metal bar with a tiny flat bit on the end
Good man keep do what you doing 🕌🏫🏫🏫🏗️🏫🏫🏫🏫🏫
Right off.......the re bar in the footing looks like it's sitting on the dirt, I later saw your using chairs but it's still too close to the ground. Using 15mm re bar ( #5 ) is really good.
That brick like finish on the outside of the foundation might look nice for the wife but the ground don't care and there's a good chance those recesses will not be sealed properly against ground water.
For concrete strength I use minimum 3,700 psi ( 25 mpa ) for the walls and for engineered foundation the minimum is 4,400 psi.
It’s hard to see in the video but the rebar sits on “chairs” so they are at the perfect height in the footings to provide tensile strength. This foundation is 2 years old and dry as the desert
Old ww2 knowledge, iron rebar reinforced concrete structure is real good for withstanding bombardment, but bad for longterm building stability. Thats cause rebar rusts, leaking rust into the concrete, which leads to structural weakness over time. What u want is some nonrusting steel reinforcement.
Great video! Thanks for putting together.
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
@@loafandjug321 He didn’t cover a lot of things in the video…doesn’t mean it wasn’t done. This video probably isn’t intended for someone like you who “knows it all”. He does a good job for explaining the basics to people who don’t know construction.
@@GrayManTraveler This video is for Su Cke Rs and Loo Sers.
Concrete should be placed not poured....water to cement ratio! Gravel below footing better! Dark soil may have organics! Rebar shown not being lifted during pour! Why not use a neoprene water stop joint? Great video just a few things we do..also you don't speak of slump factor..
Pouring concrete is an acceptable and often used term. Footings on soil is common, and compliant with building code for “undisturbed soil”.
@@patty109109Footing on soil is not common in civilized world.
Can I hire you for my home ?
Very informative video…is it recommended to have have footings on stamped gravel base?
Whats neoprene water stop joint?
i want to use 7500 psi foundation, footing and wall. is the concrete waterproof?
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
@@loafandjug321 It's undisturbed soil. You don't have to compact it.
Is it just me or that foundation wall looks thin?
me too
i look so it is just 4inch
10" walls are standard on a 9' basement.
The rebar chairs are not a good idea, they get crashed by the weight of the Concrete, exposing the rebar to the soil. We must use concrete blocks instead
weight and mass never ever ever lie, look at giant rocks or mountains for example, untouched for .well, a very long time, i find in the US even in expensive houses this is skimped on, which is strange as a 100lb block + transport can cost less than 3$ in bulk, (avg home has only 7000lb foundation...) in my mind for people building new homes this should be taken advantage of, pressure transfer and mass are the ultimate equalizers, if any concrete of any kind is cracking, its simply not strong enough to handle the pressure its being handed, again, look at large rocks or mountains under loads for eternity, some of which are literally full of snow/water 24/7
You missed an important step. Compaction of the soil before rebar and pouring concrete.
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
Nice
Nice t-shirts
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
If you want to avoid problems you must build the whole building in reinforced concrete, not wood.
as a person who build foundation walls every day i see so many mistakes 😬😬
Alrighty then. Thanks.
This design won't fly in LA, CA.
Good stuff. Not an expert, but what I would do is build up the soil to raise the grade level a couple feet, then the water table would be even further below and this would reduce chances of basement flooding.
I'd make this mandatory.
And then you could put pile-ons (not sure if that's write word) but you know, basically footers that go down a bit before you install your main footing. Make sure the soil is compact.
If everyone did this then flooding would be much less an issue. I don't even understand why anyone would install a basement at grade. Just make it higher.
Watch Never Buy A Clayton Manufactured Home on TH-cam
Very little rebar in the wall. Skimping on psi. I won't follow your advice.
GO IN SWITZERLAND 🇨🇭 , SPAIN 🇪🇸 GERMANY 🇩🇪 PORTUGAL 🇵🇹 BRAZIL 🇧🇷 AND SEE HOW THEY BUILD A FOUNDATION FOR 1000 YEAR WITH 1/2 or 3/4 STEEL REBARS = LIKE NEW YORK MANHATTAN BUILDINGS
THEY DON'T BUILD LIKE THAT IN FLORIDA IT'S JUST ON THE GROUND WHY
Because you're on limestone, the calcified remains of millions of years of tiny metamorphised sea creatures.
Great construction keep teaching The Youth Thank You.🏗️🏫🏫🏫🏫🏫🏫🏫🏫🏫
the basement was already filled with water, not draining , yikes
Concrete block is the way to go not poured concrete😮
Footing doesn't look correct
I didn't see a key in the footing shame shame shame 😮
9 foot tall by 8 inches thick that is not good at all 10 inches thick is standard for 9 feet basement ask every single engineer
Agreed. Most pour 10"
No armchair builders here, the gentleman is not Tonto but half baked and believer of the Concrete selling companies propaganda.
All the rebar you place in both: footing and wall are money flushed into the drain. You either build a reinforced concrete footing and/or wall or a concrete one. The rebar you installed doesn’t make the cut to make it a reinforced concrete for the simple reason that isn’t enough. To make it short: if the external charges will be such as to cause the concrete to crack those rebars will make absolutely no difference. Another consideration is that the position of the rebar in the footing is wrong because doesn’t offer any contribution. A beam with 8 rebars connected with stirrups would be something that makes way more sense. ….. and so on ….
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
I am building a strong foundation. :)
He didn't compact the soil *FIRST* with a excavator compactor. That guy is clueless.
I have a crack in my roof
Make sure you visit The Masjid🕌
Wait, you're pouring concrete on the dirt with no damp proof layer, and you're doing strip footings now and the floor later?
That's not how we did my floor. Continuous damp proof sheet, good beams, plenty of reinforcement, monolithic pour, and we've had droughts and floods since we built it but my floor is still solid.
Also we didn't have a desperately dangerous worksite where one wrong step could kill someone. How hard is it really to provide scaffolds for your workers to walk on? Do their lives matter THAT LITTLE to you that you just don't care if someone dies while building your house?
THIS IS A WELL BUILT HOUSE, THEY DON'T MAKE THEM LIKE THIS ANYMORE UNLESS IT'S SUPER EXPENSIVE HOMES, NOW THE FOUNDATION IS GARBAGE MATERIAL
Make sure you eat Goat meat is delicious and is Halal Thank you🐐
You should include in the information that concrete is the worst construction system there is. 25 years later concrete cancer begins to show up and eventually you have an environmental disaster in your hands, not to mention that the concrete is cold and porous, humidity will bring disease.
So Dig 9ft 8Inch?
Nice