How to Extend Concrete Slab (Lessons Learned)

hey what's going on everybody on today's project i'm going to show you how i extended the concrete slab in my backyard and kind of outline all of the lessons learned along the way because i made a ton of them and it was definitely a disaster and more than one spot so let's get into the video [Music] hey what's up guys this is actually my first concrete project which will be very apparent as we progress um so i really should have gotten it professional but i started out by excavating down about 10 inches then i went back and i power washed the existing slab to get it all clean for the next step here i am showing you the existing conditions and as you can see it's in terrible shape so i really should have demolished everything and started from scratch but i really didn't know any better so after excavating down 10 inches i hand tamped everything down to get it compacted and then i went over to the quarry and picked up some 57 stone which will be the base for my concrete slab so i really probably should have used crusher run since it compacts a little bit better but this 57 stone will be better for drainage so i'm loading everything up there and then i went back and tamped everything down to compact it so once all the stone was in place i grabbed some 1x6 lumber to use as my concrete form and i secured all that in place with stakes as you're seeing there and obviously i made sure the corners were square okay so basically at this point we have the outside forms put in place and then what i did here is i put one on each end and i'm just taking the level of it so they look pretty good level there we're not planning on draining it to this side or that side what we're going to do instead is we have the level there so essentially we have a slope going away from the house so essentially the water is going to come on this side and drain away from the house that way so the reason i have that hole there is because that is exactly where my deck is going to be bearing so i wanted to kind of create a faux footer might not have been a great idea but it'll work so what i'm doing here is i'm taking a chalk line and i'm making the marks on the cinder block which are going to indicate the top of slab elevation so i'm getting everything level there making sure the drainage is appropriate and then marking that with chalk now there may be other ways to do this but this seemed to work for me so where the existing slab is going to meet the new poured concrete slab i decided to take some half inch rebar drilled with a 5 8 inch um masonry bit and go about four or five inches into the existing slab and i'm going to drill that in as you'll see in a minute and the idea is that this will be additional concrete reinforcement along that change from existing to new which will hopefully prevent any kind of separation at that joint so as you can see i just kind of drilled into it about four inches i did this about five times across and then once the holes were drilled i took some of this epoxy and i went and i applied that within the pre-drilled hole and once i had it full i took my rebar and inserted it through again with the idea being to create a strong joint between the existing slab and the new concrete that would be poured so next up i grabbed some steel wire mesh and i cut that to serve as reinforcement for the new portion of concrete slab that's going to go above the stone so here i am cutting that out to size with some snippers and you'll see later what that looks like when we actually pour the concrete now because i'm only going to have about two inches of concrete over the existing slab i use something called weld crete which helps bond existing concrete to new concrete so i thought it would be a good idea to apply this to all of the existing slab and here i am just applying that with a roller the idea being that this will help bond the new surface layer which will be about two inches to the existing concrete and that's just a quick zoom in showing how the slab is a little bit thinner obviously on the existing portion so now it was finally time to pick up the concrete bags it ended up being 85 bags of this high strength concrete mix from sakrete i got the bulk price and then i rented this mixer for 48 dollars for four hours so the final cost came out to just over four hundred dollars as you're seeing there so once everything was mixed up my brother and i poured everything out we did a bunch of these batches and just poured it all over starting with the new portion of the slab and where he applied the wire mesh as needed to reinforce then my brother and i screeded out the top layer to try to get a uniform layer obviously we needed to fill in some low spots there and uh and then we just kind of went and started finishing it so i really had no idea how to finish concrete and i started off with this hand trowel which worked okay but this is kind of where things started going downhill what i really needed was a bull float with a long handle extension where i could smooth things out from the side and not have to walk over it and this would just allow you to get a much cleaner finish instead i had to use this stupid hand trowel and as you'll see in a minute the finish was terrible and finally i used this concrete edger around the edge to give me a nice smooth corner so here's a look at the finished product obviously it's a disaster it looks terrible the finish was awful so to try and fix this disaster i used some more weld crete on the top layer and then i mixed up some new crete which is just a concrete topper and then i mixed that up and applied it with a squeegee and it definitely helped the appearance but it still looked rough so this wasn't my best work but i did want to publish this to show kind of my mistakes with hopes that someone can learn from it now let's take a look back if this video taught you something on how not to four concrete um i really appreciate if you could drop a like down below and also leave a comment on other things that i did wrong or some additional pointers so that next time i can do a better job and you can also leave feedback that's going to be helpful to somebody watching the video so thanks again for watching and i'll see on the next one thanks you

Channel: Andrew Thron Improvements

Views: 46,697

Keywords: How to extend concrete slab, Extend concrete slab, How to extend concrete, How to pour concrete, How to pour concrete slab, concrete slab, DIY, Lessons learned, DIY concrete, DIY concrete slab, How not to pour a concrete slab, concrete slab extension, how to pour a concrete slab extension, home renovation, home improvement, Do it yourself, concrete, slab, extend concrete, how to increase size of concrete slab, slab size, concrete diy

Id: URTGmSfBxeg

Length: 6min 22sec (382 seconds)

Published: Fri May 14 2021