The Truth About Doweling Concrete Slabs!

Рет қаралды 12,950

Күн бұрын

Пікірлер: 48

@craigeslim7212 4 ай бұрын

I have a question! So unfortunately, I didn’t do my research before hiring contractor to pour us a patio slab in the backyard behind our house. To my knowledge, not only did they not put any kind of expansion joint between our foundation and the slab, but they also drilled multiple holes and doweled the new slab into our home foundation . I honestly don’t care if the patio slab itself starts to crack and break at some point, that can be replaced with only a modest amount of expense, my real concern is for our home foundation. So my question is, is the fact that they did not put any kind of expansion joint Between the slab and our foundation (at least that I can see), and the fact they drilled holes and doweled it to our foundation with Rebar, are either of those things of potential danger to our home foundation, or is it more of a risk to the patio slab itself? I hope you can answer my question because this has been weighing on my mind for over a year now, I can’t seem to find other KZbin videos or people that have much to say on the matter so I was ecstatic to come across your video today!

@joshshook2901 4 ай бұрын

I have the exact same question. Just had my patio poured a couple months ago and they tied right into the foundation. I live in an area with a high level of frost/thaw cycles. Wish I had done my research beforehand

@craigeslim7212 4 ай бұрын

@@joshshook2901 it’s a shame that these companies/ contractors don’t already know how to do it themselves correctly without being told… the only recourse we would have is to get the entire slab demolished, remove the dowels, repair the empty dowel holes, and then have another slab with a proper extension joint poured.. it would be a very expensive thing to do. So unless I’m given reason I need to I’m just going to leave it as is and ill seal the top where the slab meets the house with a polyurethane self leveling sealer, and then on the sides with a general concrete sealer, that will keep most moisture out. I still would love if he answered our question though, to get a real professional opinion!

@DecoCreteTV 3 ай бұрын

Thanks for the comment! The real danger is to the concrete slab itself, and it's rare to see damage to the foundation. If there's any significant movement of the slab during freeze-thaw cycles and the concrete is tied to a foundation, something will have to give, and that would generally be the concrete. This also depends on what part of the country you live in. If there is little to no freeze-thaw in the area, then this really isn't as big of a deal. The deeper the ground freezes, the more the slab is going to move in the winter. As we said in the video, this topic comes with some debate. It is tempting to tie floating slabs into something solid, but we like to play it safe on this one. Just let the concrete move as it wants, and the expansion joint will keep it from binding up. If they dowled your slab into the foundation, then there is really no need for any expansion joint. If the company that did this for you has been around for a while and this is their normal practice, then I really wouldn't worry too much about it. Again, this is our stance on this, and although most contractors in freeze-thaw areas would agree, there are some that say you have to tie everything together. Hopefully, this helps. Thanks for watching Deco-Crete TV!!!

@craigeslim7212 3 ай бұрын

@@DecoCreteTV thank you so much for the reply! I feel a lot better about the whole thing now!

@donaldcurtis9229 3 ай бұрын

Every Walmart building I've worked on has dowels into the foundation 10 to 15 ft

@markortiz9533 27 күн бұрын

Great video. Super helpful.

@DecoCreteTV 24 күн бұрын

Thank you!!!

@coryhanneman3345 8 ай бұрын

That little office snippet actually made me laugh out loud. Nice work, fellas!

@DecoCreteTV 8 ай бұрын

Hahaha.....Thanks Cory!!! Have a great weekend! 👊

@paoemantega8793 9 күн бұрын

V useful, thanks for sharing

@ericcairns3291 3 ай бұрын

I need to pour a slab around a pool, there is already an existing bond beam around the pool so should that be dowelled or just expansion joint? any advice greatly appreciated

@DecoCreteTV 3 ай бұрын

Thanks for the comment! A bond beam for pool would be a little different. Generally, the concrete slab would sit on top of the beam as opposed to pouring up against it like a house foundation, so I wouldn't put put any expansion joint between them. I would check with your pool builder for advise on weather to dowel into the beam or not. We would generally avoid doweling into the beam, and thick of it as more of a shelf for the slab to sit on. But, some situations are different, and the pool builder should have some advise for how this works in you area. Hopefully this helps. Thanks for watching Deco-Crete TV!!!

@TheRetroGamingPrincess 6 ай бұрын

Here's a bit of weird question, so I have a pre existing barn, the barns foundation is stationary, but given its original use case its entirely slanted towards the middle as thats how they used to keep the hogs back in the 1960s. Now I require to add concrete ontop of this existing mess to create a level workshop floor. Would I just use expansion joints around the border and then tie my floating middle slabs in together? being an INTERIOR pour its also different but working with well over 50 year old pour i feel I will be learning a lot of things that most people won't ever run into. I don't mind some lips happening because nothing is ever static and perfect, but i do not want something i cannot Dolly working pieces over size of a lip between the "exterior" barn pour and my current projected slabs. Am I thinking about this correctly using your tips?

@DecoCreteTV 6 ай бұрын

Thanks for the comment! This is defiantly a unique situation. The best thing would to remove all the old concrete and repour it. Pouring on top of existing concrete can work, but it comes with it's own set of challenges. Most full depth concrete mixes would need to be at least 2" thick. If you can bring the perimeter up 2" and fill the middle in, that would be one thing. But, 2" in the middle and trying to feather it out to nothing on the edges won't work verry good. If you are able to get enough coverage over the existing slab, than definitely use expansion joint around the perimeter. For the concrete itself, most contractors use would isolate the two slabs. Either with plastic or a layer of sand. Trying to bond the two slabs together would probably lead to some problems down the road. The other option would be to use floor leveler over the existing slab instead of pouring ready mix concrete. Our Flat Top product would work well for this, it just gets a bit expensive if you have to go really thick with it. I'll leave a link to the page on our website. Hopefully, this helps! Thanks for watching Deco-Crete TV!!! www.deco-cretesupply.com/products/overlay-mixes-repair-prep-products/flat-top

@santhoshkotagiri1204 2 ай бұрын

We are doing a concrete patio and we are in northern colorado. From the video I understand its better to not tie the patio to the foundation by attaching rebar or using dowels instead just use the concrete joints between the patio and home foundation. we had to raise 18 inch to match our patio sliding door height in the backyard. and my contractor used recycled ashphalt or roadbase from the looks of it Yet to pour the concrete in few days Any other recommendation for us. except using a concrete join where the patio meets the foundation/property Thankyou

@DecoCreteTV 2 ай бұрын

Thanks for the comment! Sounds you like you guys have things in pretty good shape! Thanks for watching Deco-Crete TV!!!

@rippinlips1133 10 күн бұрын

I’m in Concrete contractor in SW Colorado, with freeze and thaw I definitely would dowel slab in. Good luck.

@Epwnzer 8 ай бұрын

Attended the expo this year for the first time and it was great! Looking forward to the next one for sure. Anyways, when it comes to pinning into foundations, we always pin at the bottom of the slab (top of the gravel base) so that the slab cannot settle, but still can move up. What are your thoughts?

@DecoCreteTV 8 ай бұрын

Thanks for the comment! Glad to hear you enjoyed the expo!! Pinning into the foundation underneath the slab is a good way to keep the concrete from settling. We used to do that on steps and every now & then on patios. We would put the pins just under the top of the gravel base, so the concrete wouldn't actually touch them. The important thing is that the slab itself is not tied to the foundation. We ended up switching to a piece of angle iron on steps, and it works great. Here's a link to our Technique of the Week video on it. Thanks for watching!!! kzbin.info/www/bejne/nnakm6Sqjqd_ipo

@Epwnzer 8 ай бұрын

@@DecoCreteTV nice, I like that! Thanks for sharing

@ricklord7144 2 ай бұрын

Any help appreciated! I am pouring a 12x16 foundation slab to extend my original equipment storage building by double. The original is a previously poured 12x16 foundation slab from ten years ago. Should I dowel the new add-on foundation slab to the preexisting slab? 70 yrs old, retired doing all my own work! Thanks much!

@DecoCreteTV 2 ай бұрын

Thanks for the comment! If both of the floors are on a foundation that won't be affected by freeze/thaw, then yes, I would dowel them together. The problems start when one of the slabs moves up and down from freeze/thaw and the other one does not. This can also depend on where you live and how much freeze/thaw the concrete will go through. You could check your local building code or ask some concrete contractors around your area to see how they would handle it. Hopefully this helps! Thanks for watching Deco-Crete TV!!!

@ricklord7144 2 ай бұрын

@@DecoCreteTV Thank you so much for the quick response. We live in the Mid-Willamette Valley in Oregon. Not much in terms of freezing here. Maybe a few days a year. Your video was very informative! With labor costs being so out of this world and us being on social security, I have to do as much of my desired projects on my own. Hence the University of KZbin! Blessings!

@franciscocordova9561 28 күн бұрын

I have a quick question i have an existing garage that I'm adding a big slab behind it to make it longer. Can I tie the new slab to the exiting garage slab?

@DecoCreteTV 24 күн бұрын

Thanks for the comment! Is the new slab gonna be part of the same garage; as in under the same roof? Is it also going to be on a foundation? If so, then yes, tying the two slabs together would be a good idea. If the new slab is not gonna have a roof over it or not on a foundation, then we not recommend tying them together. Hopefully this helps. Thanks for watching Deco-Crete TV!!!

@Aqufrank 8 ай бұрын

Every commercial project I’ve been on requires floating slabs to be tied into building with dowels at all door openings. Without that, how are you supposed to prevent frost from heaving the slab to the point the door doesn’t even open? Your example works because your slab is 2” below your door threshold and you have the room but that is not ADA compliant and on commercial projects your sidewalk needs to meet with the finished floor of the building.

@DecoCreteTV 8 ай бұрын

Thanks for the feedback! If it's spec'd for the job, then you have to do it! Thanks for watching Deco-Crete TV!!

@donaldcurtis9229 3 ай бұрын

That's why they put Styrofoam around the perimeter

@kylemorse1049 2 ай бұрын

I have a 4 foot gap between my house and driveway I’d like to fill in. I assume an expansion joint on the house side and dowel into the driveway?

@DecoCreteTV 2 ай бұрын

Thanks for the comment! Yes, that would be the best way of handling this kind of situation. Thanks for watching Deco-Crete TV!!!👍

@xy404 4 ай бұрын

should i use expansion foam to separate the drivewway from the gutter? or should i just drill into the gutter and put in 3/8 rebar and tie it into the exisiting rebar ?

@DecoCreteTV 4 ай бұрын

Thanks for the comment! This could work either way and there is no real right or wrong. I would check with some other concrete contractors around your area, just to see how they are handling this kind of situation. We would normally use expansion joint for that, and avoid tying into the curb & gutter. Thanks for watching Deco-Crete TV!!!

@bryceholohan7901 Ай бұрын

hi jeff i’m doing a small concrete job and I need to elongate a concrete light post. The concrete is very old but sturdy. I want to drill some pilot holes and then put rebar in and pour a new extension but i’m worried about cracking the concrete when drilling for the the rebar holes any tips for this beginner?

@DecoCreteTV Ай бұрын

Thanks for the comment! The first tip would be to use right equipment. A quality hammer drill & masonry bit are a must, we prefer the spline style drills because you will need a fairly large bit. If you are using 1/2" (#4) rebar for the dowels, you would use a 5/8" drill bit, #3 bar would use a 1/2" bit, and so on. Basically, the hole needs to 1/8" larger in diameter than the rebar. Most local tool rental shops will these available for rent. The next thing would be to keep your holes at least 2"-3" in from the edges. It's hard to be very precise when drilling these holes, give yourself some room so you don't end up drilling too close to the edge and creating a weak spot. Also, take your time and let the drill do the most of the work, don't try to force it. Sometimes you might even hit a piece of rebar in the concrete (if there is any in it). If that happens, again don't force it. Give it a second to see if it wants to drill through it, and if it doesn't, just move the bit over to one side or the other and try again. These drills and bits are made for this and it's uncommon that it would crack the concrete, as long as you take you time and stay away from the edges. Hopefully this helps! Thanks for watching Deco-Crete TV!!!

@duc99804 4 сағат бұрын

Every clip shown on here showed no bar chairs… wouldn’t think to highly of advice provided here!

@GrumpyAndCricket 8 ай бұрын

Great info. Have a fun weekend.

@DecoCreteTV 8 ай бұрын

You too, brother!!! Thanks for the comment!✌️

@GRUBB-MUDD 8 ай бұрын

Ive walked on the slabs at yur shop

@DecoCreteTV 8 ай бұрын

Thanks Bobby!! We always love hearing from you! Have a great weekend, brother!!👊

@henryfehr6202 8 ай бұрын

When i dowel 2 slabs together i aleays use epoxy coated rebar dowels. Concrete always shrinks a bit and your going to get moisture in between causing the rebar to rust.

@DecoCreteTV 8 ай бұрын

Thanks for the comment!!!

@miatingz3568 13 күн бұрын

My contractor didn’t use epoxy rebar, I can see there is a very fine gap between new concrete slab and house foundation, I’ll seal it by Polyurethane. But my question is if the rebar rust, could it damage my foundation, make it crack? They drill holes every 30cm, and there are 14 holes. I appreciate if you can answer my question. I am struggling if I should rip up this new slab , take off rebars, fill those holes, and redo one with expansion joints.