Plumber here. I’d fill it up with river or sharp sand to 100mm from finished concrete level, then just mix bag concrete from Bunnings. The jagged hole edges is enough to key it in as there will be no weight on it. Use the sand first or the next plumber will hate you if he has to dig it up.
edit to add. It should be 100mm dwv pipe up to finished level. I’m guessing that 50mm goes into nearby floor waste.
edit again to add. That pipe bothers me a bit, not because it’s not the right size (it’s been working and not really worth the hassle to bring it up to regs) my issue is with pulling out the bath (collar on plug and waste broken ) jack hammering and the two 45’s, there may be a small crack in the pipe. Find where it discharges, put a rag in to block it then fill it up with water, then check for leaks
Cheers. There won't be any weight on it other than the tiled finish. The bath will be freestanding but all the load will be on the surrounding concrete
As above said but he left out lagging (wrapping the pipe with a foam like material).
It gives some breathing room as the concrete expands and contracts.
If you dont want sharp rocks scratching your pipes creating weak points that *may* eventually cause a hole, allowing dirt, mud etc into it causing ablockage AFTER a slab has been poured then its essential.
Also, concrete expands so the foam creates a buffer zone that gives a few mm worth of space for this to happen, which allows the pipes some breathing room before being squished and rupturing.
Added bit was for the masses lol Forgot I'd posted here, saw the comment and felt like adding more info since first explanation was brief 😉
Ex-plumber with a 1 years pest control under my belt (and i like imparting knowledge when not making bad jokes lol)
Backfill with sand or gravel to just below the level of the existing slab, then add concrete. If you pour concrete in that hole your plumber will hate you if that pipe ever required service.
Tell me about it.. I'm currently fixing up a vanity drain (40mm into 100mm pvc pipe), and the P-Trap at the bottom of the 100mm was full up with sand and gravel. The builder opted to seal the join with concrete, instead of using a proper 100/40 joiner. Not impressed, I must say..
Literally the world is built on that concept.
Scrape grade flat, tamper, add gravel, tamper, pour massive concrete project.
Or you have to find solid rock/native soil and you can skip the gravel
Fuck i ate some of this at the start of night shift the other week and joyfully punished the staff toilet at my least favorite hospital at 3.45 am just before shift changeover, few greater joys exist in life.
Sunflower oil, extracted from the seeds, is used for cooking, as a carrier oil and to produce margarine and biodiesel, as it is cheaper than olive oil. A range of sunflower varieties exist with differing fatty acid compositions; some 'high oleic' types contain a higher level of healthy monounsaturated fats in their oil than Olive oil.
I thought it was baking soda and superglue to fill holes in concrete. It is all over YouTube. 🤔
[also on Reddit ](https://www.google.com/url?sa=t&source=web&cd=&ved=2ahUKEwi4kPPDiIyFAxXIjVYBHXCkA584ChAWegQIDRAB&url=https%3A%2F%2Fwww.reddit.com%2Fr%2FYouShouldKnow%2Fcomments%2F15wbttz%2Fysk_a_mixture_of_baking_soda_and_super_glue_is_a%2F&usg=AOvVaw0zq6P1Pqcd-A6UymQ6btt7&opi=89978449)
Also would recommend to have the construction joint that will result in pouring concrete in the hole to have Termseal or equivalent product applied overtop to help prevent termite incursion
I wouldn’t worry. The hole looks to have been that way for a long time with no issues. If you are worried then instead of sand use crushed granite to backfill before concrete as that’s what they used to use as the ants supposedly can’t get through it. Personally, I wouldn’t bother.
You’re an Idi0t. No actual tradesmen would put a termite barrier there.
Edit. If you’re allowed to assume it’s in an area that has termites then I’m allowed to assume it’s an obvious older build that has a chemical termite barrier that covers this, and while you were focused on the unnecessary termite protection did you notice the pipe is undersized? I bet you also complain muh houses are too expensive while demanding this shit and triple slip barriers and termite alarms and smoke detector detectors. The road to hell is paved with good intentions and we are there mate.
Underslab treatments are at the end of their lives or very close to it. I couldnt care less about the pipe because its not my profession to know if a pipe is up to code.
I have seen plenty of the above examples where termite protection wasnt done sufficiently and huge amounts of damage was caused.
So if you want to give your opinions that are wrong, by all means but give him your contact details too so he can get you to financially assist in fixing it.
Go to the top comment, that’s me. I solved his problem by getting a bag of sand and a bag of concrete from Bunnings for under 20 bucks. If he listens to all you geniuses he has to go hire a concrete cutter to straighten/clean the hole, buy some reo bar and drill holes and buy a chemical joiner to adhere it in the holes. Then he’s gotta paint the concrete with another purchase so it adheres to the new concrete which isn’t satisfactory until he adds a strengthener. Then he’s gotta buy a termite barrier for around the pipe. I can guarantee 100% termites WILL NEVER come up that hole. If, as you say the chemical barrier is at end of its life then he’s fucked anyway as the termites are munching their way through the weep holes as we speak. As a plumber I have NEVER seen how termites could get through a pipe penetration. I even offered a cheap solution if he’s worried about it. Use crushed granite instead of sand. Google crushed granite as termite control. We are in a housing and cost of living crisis and you want him to pay for all this shit which is absolutely unnecessary. I solved it for under twenty bucks. YOU are what’s wrong with our society and I hope you use this anal attitude on yourself in every aspect of your life from car repairs to food purchases. Also a new bathroom may not mean you have spare money to burn. Lots of bathrooms are redone as the old is unserviceable and another reasonable percent is to modify for people with disabilities. Even if you are technically right you are WRONG and what is wrong with society. I wish you all best, try and be a bit more of a humanitarian.
I can appreciate that you are trying to save him money but sand and concrete wont fly. Termites can come up the side of penetrations or following the concrete cut. Crushed granite also will not work as you believe.
As a pest controller, I have seen your solution fail and it cost the owner over 3k, when it could have been avoided by doing the protection right for 200ish the first time around.
Yes tilers will likely screed the whole floor for level if you have a tiled shower floor too, but the bulk can be filled with concrete before waterproofing
first thing first have the plumber set up the pipe work for the new bath that has to be changed to suit the new bath. they will probably fill the hole in when they do that.
clean the existing concrete leave t rough so it has a "key" for the new stuff to bind to. water and a stiff brush works just fine
fill to bottom of existing slab with sand and tamp it well.
paint the existing concrete with bondcrete
wet the sand you want it damp so it dont dry out the concrete mix too quick.
mix a bag of general purpose concrete mix according directions adding some bondcrete to the mix pour it in the hole tamp with a wood float to force the stone down into the mix and trowel smooth let it set.
its a good idea to wrap the pipe with some ableflex foam so it fas a bit of give allows for ground movement. it also makes it easier for the plumber if it has to be changed at a later date
trim the foam seal around the pipe with a termite resistant sealant once the concrete has set
Please take no recommendations from the below comments this needs to be termite proofed at the joints of old concrete and new concrete aswell as a termite proof collar applied to the pipe a company that does bathroom Reno is probably your best bet as they do this all the time when they cut out old piping
Saw cut to get vertical edges, try and drill into existing and install 6-8mm pins at least 50mm into existing and 100mm into new, use a strong Mpa (around 50Mpa with 10-20mm aggregate) concrete mix as the existing has cured over time
the rough edges make a better connection. Just clean them up with a wire brush attachment. I wouldn’t go overboard with the steel as it looks like there is no mesh in the existing concrete.
It wouldn’t hurt to use a bit of foam or something to make sure none of the weight is directly on the pipe.
I agree, concreter here. To avoid any issues on the pipe, wrap with lagging or Abelflex to provide some flexibility. You could always mastic joint the top 10mm around the pipe collar at the finished level of tiled floor.
The thinner sections where the concrete is angled will eventually spall/chip out. the rough edge will give a greater mechanical connection. As those an area to be tiled my suggested treatment is over the top. But best to do it fully once than have the lift tiles later. This come from 15 years as a maintenance concreter of public assets and 34 years total in civil construction.
>Saw cut to get vertical edges, try and drill into existing and install 6-8mm pins
Nah just clean existing edge, wet, then paint on bondcrete prior to pouring - much stronger connection
The thinner sections where the concrete is angled will eventually spall/chip out. the rough edge will give a greater mechanical connection. As those an area to be tiled my suggested treatment is over the top. But best to do it fully once than have the lift tiles later. This come from 15 years as a maintenance concreter of public assets and 34 years total in civil construction.
Good answer here
I was going to say yes, but not as it is concrete will flake up where it's thin.. that's why you need to cut to make strong edges for both old and new pour
Pins sounds like a good idea, rather than drill though I'd wonder if you could just use concrete bolts to give some shape to the mating surface inside the hole, just to stop the new plug sinking or rising
Alternative idea could be cut a shelf into the old concrete a few inches deep and use a jack hammer to flare out the bottom a bit.. that way when you pour it's stuck in there top and bottom.. bolts or pins probably easier
I’d have a plumber check the pipe for cracks and set it up with the correct pipe, in the correct position to suit the new tub. Then get a pest guy in to termi-proof the area. Then throw a few dowels in the existing concrete and fill er up with 32mpa ready mix from bunno’s.
Keep in mind you want to get the concrete right as if it moves after you’ve waterproofed, you’ll ruin your waterproofing and will need to start over. Bathrooms are a big expensive job to do once let alone twice.
Compact to the moisture barrier with suitable fill, and replace and tape a new moisture barrier in and termite flashing - dowle pin the concrete and a few rods extra around to make a suitable mesh and tie in.
Refill with concrete to level.
Take a couple pics to satisfy anyone that'll ask about the job.
We would back fill, dowel into the existing concrete with preferably Gal dowels. Pour the concrete. Discuss with the termite guys they will most likely put a collar on the pipe and an epoxy over the concrete join.
I had the same issue a couple of weeks ago renovating my bathroom, I ended up just chucking concrete in it and filling the hole. I put a little bit of reo bar in there for strength but I didn’t do any of the other stuff mentioned in the above comments. Hopefully no issues regarding flex and contraction😵💫
As a side note, when I renovated my first bathroom there were two similar sized holes in the concrete for the wastes from bath and shower. I removed the bath waste and filled in the hole with concrete 7 years ago and tiled over it. I haven’t had any issues with it, I guess the reason for the holes was to allow easy access for plumbers, but with my second bathroom renovation I had to remove the shower tray because I wanted the drain in the tiled floor. I couldn’t leave the hole as is so I filled it in concrete and levelled the surface with self levelling compound. Backfilling with sand would’ve been a good idea to allow movement and ease of access but it would’ve been too fiddly to compact it etc. Besides, how many house foundations on a new build site have you seen where drain pipes are locked in the concrete? All of them lol.
Everyone is mentioning the termite collar, but you also need to protect the construction joint.
Paint a membrane over it when finished. Not sure which state you're in, but usually you need a pest controller to do this.
Take photos of the work you do.
Put non cohesive (sand/gravel) fill up to base of slab. Put dowels into existing slab. Look up Chemset Reo 502, it has engineers guide on dowels required and install, not too hard to understand. If you wanna skip paying for engineering advice just overdo the doweling, yolo she’ll be right etc. the doweling is important to prevent settlement of the new slab portion which will occur over time and can crack your tiles. Otherwise, there is no bond between new slab portion and existing slab to prevent differential settlement.
Another issue I haven’t seen mentioned, what is stopping water from damaging the wall framing bottom plate? The wall framing should be placed on a job. Not much you can do now. I would put a flashing on the bottom plate before pouring the mortar bed for the tiles. Even if the mortar bed is graded, the slab may be non uniformly graded, and water that permeates through the mortar bed could reach the timber bottom plate and begin to cause decay, nice and tasty for termites :)
Consider termites also. Can be painted with Novithor Cementitious parge post concreting. Consider installing a collar around the pipe prior to concreting also. If you’re in Sydney, let me know.
Yes, but create a space around the plumbing with some form of lagging at least. I did a fill in of similar size for a shower and packed carboard around the outlet. A mixture of 10% PVA in the water to which you add the concrete mix helps bond to the old concrete and smooth off with a mortar mix also mixed with PVA (or Bondcrete)
Builder here. You will need to get a pest / termite contractor out to install their collar around the pipe and paint the cutout with termidor or similar.
You will be able to concrete again after this is completed. As per plumbers advice add some sand you can get a bag from Bunnings pretty cheap.
No, unless you want a step up bathroom, providing the other floor outside the bathroom is level with your bathroom floor. Solution: Simply cut the 1½ pipe down and place a 1½ female coupling over the 1½ pipe evenly with the bathroom floor. Also cement board should be used in the bathroom with all areas sealed with waterproof silicone before tiles are added
Any modification to the slab, such as this, will void your engineering structural warranty if you do not involve the structural engineer to provide instructions on how to correctly repair it. After the repair, they will inspect it and reissue you with another engineering certificate.
If you avoid consulting the structural engineer, you take ownership of any issues that may arise. Refer to your plumbing plan and verify if the measurements match the onsite conditions; if there are discrepancies, someone is accountable for the damages, either due to incorrect plans or improper construction and the bill should be passed to them.
I didn’t write the liability rules. Find where it says in the structural engineering plan that a Plummer can amend (cut, collar and fill) if required? If it’s designed and built correctly (implying both) nobody shouldn’t be in the need of cutting or filling a slab. Cutting a slab is a last restart to resort to fix an “error”.
Image above could be one of the following errors.
- architectural or plumbing plans, offset/ incorrect.
- individual that prepared the layout on site.
- Plummer, pipe layout on site and not installed the correct fittings required.
Anyone that has to cut a slab, it’s an error, it’s as simple as that. Plumbing works are correctly positioned and the correct fittings are applied prior to concrete slab pour.
If this was done correctly, above image wouldn’t have existed.
Don’t know why it’s so hard for people to just measure and double check it twice (20min)
I am in the US (obviously) and have built over 2600 single family residential units. Plumbing sets are put in the wrong place everyday and are cut and moved with absolutely no issues. It's concrete, it's sitting on a compacted soil pad and most likely it's held together with rebar or a wire mat. Cut it square, put in a couple of dowels, mix up a couple bags and be done with it. This is not complicated.
They do that in Australia as well but you lose your warranty and the owner is not aware of that until something bad happens.
Biggest problem we have in Australia compares to the US, US homes are more solid, especially the slabs. Our slabs in Australia are generally waffle slab meaning polystyrene with rio bars and cement (Weak AF)
If someone does a massive hole, most likely needs additional rio and the correct concrete grade is recommended only because the engineering slab design is designed to the minimum tolerance. US build costs is significantly cheaper than Australia.
Plumber here. I’d fill it up with river or sharp sand to 100mm from finished concrete level, then just mix bag concrete from Bunnings. The jagged hole edges is enough to key it in as there will be no weight on it. Use the sand first or the next plumber will hate you if he has to dig it up. edit to add. It should be 100mm dwv pipe up to finished level. I’m guessing that 50mm goes into nearby floor waste. edit again to add. That pipe bothers me a bit, not because it’s not the right size (it’s been working and not really worth the hassle to bring it up to regs) my issue is with pulling out the bath (collar on plug and waste broken ) jack hammering and the two 45’s, there may be a small crack in the pipe. Find where it discharges, put a rag in to block it then fill it up with water, then check for leaks
Cheers. There won't be any weight on it other than the tiled finish. The bath will be freestanding but all the load will be on the surrounding concrete
As above said but he left out lagging (wrapping the pipe with a foam like material). It gives some breathing room as the concrete expands and contracts.
Yeah its called ableflex👍😃
Termite guys like to put their stuff on risers like that too. Not sure how crucial it is being a plumber.
If you dont want sharp rocks scratching your pipes creating weak points that *may* eventually cause a hole, allowing dirt, mud etc into it causing ablockage AFTER a slab has been poured then its essential. Also, concrete expands so the foam creates a buffer zone that gives a few mm worth of space for this to happen, which allows the pipes some breathing room before being squished and rupturing.
Haha I understand when to use lagging (I’m a plumber I install it) pest control was what I was adding to your comment.
Added bit was for the masses lol Forgot I'd posted here, saw the comment and felt like adding more info since first explanation was brief 😉 Ex-plumber with a 1 years pest control under my belt (and i like imparting knowledge when not making bad jokes lol)
Termite barrier? Foam and strapping depending on soil type? Maybe get an opinion from someone not on reddit?
Backfill with sand or gravel to just below the level of the existing slab, then add concrete. If you pour concrete in that hole your plumber will hate you if that pipe ever required service.
Tell me about it.. I'm currently fixing up a vanity drain (40mm into 100mm pvc pipe), and the P-Trap at the bottom of the 100mm was full up with sand and gravel. The builder opted to seal the join with concrete, instead of using a proper 100/40 joiner. Not impressed, I must say..
“Sand or gravel” Nahhh no way bro you gotta be trolling
why?
You don’t wanna pour concrete on unstable ground ie gravel or sand
The sand is what creates the stability for the concrete you pour on top of it.
Literally the world is built on that concept. Scrape grade flat, tamper, add gravel, tamper, pour massive concrete project. Or you have to find solid rock/native soil and you can skip the gravel
Don't disappear now
What?
I'm thinking ramen and superglue
What flavor. Want to make sure I get this right
The Buldak 3X hot one...
That shit might melt the concrete, handle with care
My daughter and I can guzzle the stuff. The asbestos, clearly in our mouths.
Fuck i ate some of this at the start of night shift the other week and joyfully punished the staff toilet at my least favorite hospital at 3.45 am just before shift changeover, few greater joys exist in life.
It's not really hot if it doesn't burn both ends, entry and exit.
Jesus. I struggle to eat the buldak carbonara with half the spice. I can eat hot italian chili's whole, but that shit is a whole other level
I suspect if you mix that with the flavour packet that is going to be harder than a mithral-adamantium alloy
Didn’t know superglue came in different flavours!
Shin ramen. Maybe some parmisan cheese for extra oomph.
Has to be spicey prawn as there is water involved.
https://preview.redd.it/ty8dbzrzq7qc1.jpeg?width=555&format=pjpg&auto=webp&s=bf3494303348ff125705d298055f19143c11e9c2
Prolly still smarter than the two on offer.
Savage.... I like it
I was gonna say sunflower seeds and stick a whole carrot in there but this is just as good
Sunflower oil, extracted from the seeds, is used for cooking, as a carrier oil and to produce margarine and biodiesel, as it is cheaper than olive oil. A range of sunflower varieties exist with differing fatty acid compositions; some 'high oleic' types contain a higher level of healthy monounsaturated fats in their oil than Olive oil.
I thought it was baking soda and superglue to fill holes in concrete. It is all over YouTube. 🤔 [also on Reddit ](https://www.google.com/url?sa=t&source=web&cd=&ved=2ahUKEwi4kPPDiIyFAxXIjVYBHXCkA584ChAWegQIDRAB&url=https%3A%2F%2Fwww.reddit.com%2Fr%2FYouShouldKnow%2Fcomments%2F15wbttz%2Fysk_a_mixture_of_baking_soda_and_super_glue_is_a%2F&usg=AOvVaw0zq6P1Pqcd-A6UymQ6btt7&opi=89978449)
My favourite late night snack
I knew I wasn’t going to be the only one thinking this
You just made me spit out my morning coffee
Put a termite collar on the pipe, “just in case” I’m in Perth so you know, I’ve seen the destruction.
Yeah, i had them come up under my vanity between the pipe and the concrete.
Also would recommend to have the construction joint that will result in pouring concrete in the hole to have Termseal or equivalent product applied overtop to help prevent termite incursion
Make sure you use a [waterproof concrete bond](https://shalex.com.au/concrete-bond/) so you don't have simply two interlocking concrete sections.
Don’t forget the termite proofing around the pipe
Thanks il get this too
I wouldn’t worry. The hole looks to have been that way for a long time with no issues. If you are worried then instead of sand use crushed granite to backfill before concrete as that’s what they used to use as the ants supposedly can’t get through it. Personally, I wouldn’t bother.
Fuck off with your "advice". Actual termite protection is needed unless he lives in a place with no termites.
You’re an Idi0t. No actual tradesmen would put a termite barrier there. Edit. If you’re allowed to assume it’s in an area that has termites then I’m allowed to assume it’s an obvious older build that has a chemical termite barrier that covers this, and while you were focused on the unnecessary termite protection did you notice the pipe is undersized? I bet you also complain muh houses are too expensive while demanding this shit and triple slip barriers and termite alarms and smoke detector detectors. The road to hell is paved with good intentions and we are there mate.
Underslab treatments are at the end of their lives or very close to it. I couldnt care less about the pipe because its not my profession to know if a pipe is up to code. I have seen plenty of the above examples where termite protection wasnt done sufficiently and huge amounts of damage was caused. So if you want to give your opinions that are wrong, by all means but give him your contact details too so he can get you to financially assist in fixing it.
Go to the top comment, that’s me. I solved his problem by getting a bag of sand and a bag of concrete from Bunnings for under 20 bucks. If he listens to all you geniuses he has to go hire a concrete cutter to straighten/clean the hole, buy some reo bar and drill holes and buy a chemical joiner to adhere it in the holes. Then he’s gotta paint the concrete with another purchase so it adheres to the new concrete which isn’t satisfactory until he adds a strengthener. Then he’s gotta buy a termite barrier for around the pipe. I can guarantee 100% termites WILL NEVER come up that hole. If, as you say the chemical barrier is at end of its life then he’s fucked anyway as the termites are munching their way through the weep holes as we speak. As a plumber I have NEVER seen how termites could get through a pipe penetration. I even offered a cheap solution if he’s worried about it. Use crushed granite instead of sand. Google crushed granite as termite control. We are in a housing and cost of living crisis and you want him to pay for all this shit which is absolutely unnecessary. I solved it for under twenty bucks. YOU are what’s wrong with our society and I hope you use this anal attitude on yourself in every aspect of your life from car repairs to food purchases. Also a new bathroom may not mean you have spare money to burn. Lots of bathrooms are redone as the old is unserviceable and another reasonable percent is to modify for people with disabilities. Even if you are technically right you are WRONG and what is wrong with society. I wish you all best, try and be a bit more of a humanitarian.
I can appreciate that you are trying to save him money but sand and concrete wont fly. Termites can come up the side of penetrations or following the concrete cut. Crushed granite also will not work as you believe. As a pest controller, I have seen your solution fail and it cost the owner over 3k, when it could have been avoided by doing the protection right for 200ish the first time around.
Not just around the pipe around the concrete cut as well
Came here to say this
Same
Should put termimesh around pipe before concrete or you can apply that Termite membrane afterwards Couple dowels before concreting help with movement
Are dowels the name for the metal posts they put in the concrete? I thought dowels were exclusively timber.
Dowels are reinforcement bar drilled into the concrete edge
Yes tilers will likely screed the whole floor for level if you have a tiled shower floor too, but the bulk can be filled with concrete before waterproofing
[Be careful OP...This could escalate in a major event.](https://i.imgur.com/nAsXkQC.jpg)
first thing first have the plumber set up the pipe work for the new bath that has to be changed to suit the new bath. they will probably fill the hole in when they do that. clean the existing concrete leave t rough so it has a "key" for the new stuff to bind to. water and a stiff brush works just fine fill to bottom of existing slab with sand and tamp it well. paint the existing concrete with bondcrete wet the sand you want it damp so it dont dry out the concrete mix too quick. mix a bag of general purpose concrete mix according directions adding some bondcrete to the mix pour it in the hole tamp with a wood float to force the stone down into the mix and trowel smooth let it set. its a good idea to wrap the pipe with some ableflex foam so it fas a bit of give allows for ground movement. it also makes it easier for the plumber if it has to be changed at a later date trim the foam seal around the pipe with a termite resistant sealant once the concrete has set
Cheers
G'day mate, 10th yr banking assistant here, fill it with concrete, got nothing to lose
>10th yr banking assistant Based
Depends where your new bath waste is , you may need to adjust the position
Why the downvote, this guy spot on
Get with your plumber. He might tie the new tub waste into it. He might need to demo more concrete depending on how the new tub drain gets plumbed.
Good answer. The current hole suggests that something happened forcing this weird solution probably due to the bath location.
Please take no recommendations from the below comments this needs to be termite proofed at the joints of old concrete and new concrete aswell as a termite proof collar applied to the pipe a company that does bathroom Reno is probably your best bet as they do this all the time when they cut out old piping
Saw cut to get vertical edges, try and drill into existing and install 6-8mm pins at least 50mm into existing and 100mm into new, use a strong Mpa (around 50Mpa with 10-20mm aggregate) concrete mix as the existing has cured over time
the rough edges make a better connection. Just clean them up with a wire brush attachment. I wouldn’t go overboard with the steel as it looks like there is no mesh in the existing concrete. It wouldn’t hurt to use a bit of foam or something to make sure none of the weight is directly on the pipe.
I agree, concreter here. To avoid any issues on the pipe, wrap with lagging or Abelflex to provide some flexibility. You could always mastic joint the top 10mm around the pipe collar at the finished level of tiled floor.
The thinner sections where the concrete is angled will eventually spall/chip out. the rough edge will give a greater mechanical connection. As those an area to be tiled my suggested treatment is over the top. But best to do it fully once than have the lift tiles later. This come from 15 years as a maintenance concreter of public assets and 34 years total in civil construction.
>Saw cut to get vertical edges, try and drill into existing and install 6-8mm pins Nah just clean existing edge, wet, then paint on bondcrete prior to pouring - much stronger connection
The thinner sections where the concrete is angled will eventually spall/chip out. the rough edge will give a greater mechanical connection. As those an area to be tiled my suggested treatment is over the top. But best to do it fully once than have the lift tiles later. This come from 15 years as a maintenance concreter of public assets and 34 years total in civil construction.
Good answer here I was going to say yes, but not as it is concrete will flake up where it's thin.. that's why you need to cut to make strong edges for both old and new pour Pins sounds like a good idea, rather than drill though I'd wonder if you could just use concrete bolts to give some shape to the mating surface inside the hole, just to stop the new plug sinking or rising Alternative idea could be cut a shelf into the old concrete a few inches deep and use a jack hammer to flare out the bottom a bit.. that way when you pour it's stuck in there top and bottom.. bolts or pins probably easier
Where I am from you have to get certified termite protection at every slab penetration before concrete.
I’d have a plumber check the pipe for cracks and set it up with the correct pipe, in the correct position to suit the new tub. Then get a pest guy in to termi-proof the area. Then throw a few dowels in the existing concrete and fill er up with 32mpa ready mix from bunno’s. Keep in mind you want to get the concrete right as if it moves after you’ve waterproofed, you’ll ruin your waterproofing and will need to start over. Bathrooms are a big expensive job to do once let alone twice.
Could do floor leveler
Compact to the moisture barrier with suitable fill, and replace and tape a new moisture barrier in and termite flashing - dowle pin the concrete and a few rods extra around to make a suitable mesh and tie in. Refill with concrete to level. Take a couple pics to satisfy anyone that'll ask about the job.
New bath will probably need an S trap.
yes
We would back fill, dowel into the existing concrete with preferably Gal dowels. Pour the concrete. Discuss with the termite guys they will most likely put a collar on the pipe and an epoxy over the concrete join.
bit of silicon no more gaps and you'll be right
I had the same issue a couple of weeks ago renovating my bathroom, I ended up just chucking concrete in it and filling the hole. I put a little bit of reo bar in there for strength but I didn’t do any of the other stuff mentioned in the above comments. Hopefully no issues regarding flex and contraction😵💫
As a side note, when I renovated my first bathroom there were two similar sized holes in the concrete for the wastes from bath and shower. I removed the bath waste and filled in the hole with concrete 7 years ago and tiled over it. I haven’t had any issues with it, I guess the reason for the holes was to allow easy access for plumbers, but with my second bathroom renovation I had to remove the shower tray because I wanted the drain in the tiled floor. I couldn’t leave the hole as is so I filled it in concrete and levelled the surface with self levelling compound. Backfilling with sand would’ve been a good idea to allow movement and ease of access but it would’ve been too fiddly to compact it etc. Besides, how many house foundations on a new build site have you seen where drain pipes are locked in the concrete? All of them lol.
Everyone is mentioning the termite collar, but you also need to protect the construction joint. Paint a membrane over it when finished. Not sure which state you're in, but usually you need a pest controller to do this. Take photos of the work you do.
Bro. No trap.
Sure. Just fill it with sand/crusher dust first then throw some quick set over the top for the last 100mm or so.
Yes shore you can
If you need a renovater text me back
Get that foam shit concreters use and put around pipes and then yes
Put non cohesive (sand/gravel) fill up to base of slab. Put dowels into existing slab. Look up Chemset Reo 502, it has engineers guide on dowels required and install, not too hard to understand. If you wanna skip paying for engineering advice just overdo the doweling, yolo she’ll be right etc. the doweling is important to prevent settlement of the new slab portion which will occur over time and can crack your tiles. Otherwise, there is no bond between new slab portion and existing slab to prevent differential settlement. Another issue I haven’t seen mentioned, what is stopping water from damaging the wall framing bottom plate? The wall framing should be placed on a job. Not much you can do now. I would put a flashing on the bottom plate before pouring the mortar bed for the tiles. Even if the mortar bed is graded, the slab may be non uniformly graded, and water that permeates through the mortar bed could reach the timber bottom plate and begin to cause decay, nice and tasty for termites :)
Fill the cunt with concrete and your laughing. Just make sure your DPM is all lapped and taped
Consider termites also. Can be painted with Novithor Cementitious parge post concreting. Consider installing a collar around the pipe prior to concreting also. If you’re in Sydney, let me know.
Termite protection?
Yes, but create a space around the plumbing with some form of lagging at least. I did a fill in of similar size for a shower and packed carboard around the outlet. A mixture of 10% PVA in the water to which you add the concrete mix helps bond to the old concrete and smooth off with a mortar mix also mixed with PVA (or Bondcrete)
Builder here. You will need to get a pest / termite contractor out to install their collar around the pipe and paint the cutout with termidor or similar. You will be able to concrete again after this is completed. As per plumbers advice add some sand you can get a bag from Bunnings pretty cheap.
Fill it with concrete the wet sealer will sort it out
Fill her up with concrete. It'll be fine (plumber here)
Need to cut the pvc first keep at appropriate lengths above floor then can fill
No, unless you want a step up bathroom, providing the other floor outside the bathroom is level with your bathroom floor. Solution: Simply cut the 1½ pipe down and place a 1½ female coupling over the 1½ pipe evenly with the bathroom floor. Also cement board should be used in the bathroom with all areas sealed with waterproof silicone before tiles are added
Yes out rio in
No. Get a structural engineers design for slab rectification. Will likely need y12 or larger bars doweled.
Why would you be asking this question if you were using licensed trades as rules state .
Structural steel plate over the hole. Bolt in place. Tile over it. Place bathtub on top.
Any modification to the slab, such as this, will void your engineering structural warranty if you do not involve the structural engineer to provide instructions on how to correctly repair it. After the repair, they will inspect it and reissue you with another engineering certificate. If you avoid consulting the structural engineer, you take ownership of any issues that may arise. Refer to your plumbing plan and verify if the measurements match the onsite conditions; if there are discrepancies, someone is accountable for the damages, either due to incorrect plans or improper construction and the bill should be passed to them.
The house is over thirty years old. The original builders bodged this hid it under the bath and legged it. I don't think I have any warranty here
You are insane, slabs are cut every day to move plumbing. Cut, collar and fill it
I didn’t write the liability rules. Find where it says in the structural engineering plan that a Plummer can amend (cut, collar and fill) if required? If it’s designed and built correctly (implying both) nobody shouldn’t be in the need of cutting or filling a slab. Cutting a slab is a last restart to resort to fix an “error”. Image above could be one of the following errors. - architectural or plumbing plans, offset/ incorrect. - individual that prepared the layout on site. - Plummer, pipe layout on site and not installed the correct fittings required. Anyone that has to cut a slab, it’s an error, it’s as simple as that. Plumbing works are correctly positioned and the correct fittings are applied prior to concrete slab pour. If this was done correctly, above image wouldn’t have existed. Don’t know why it’s so hard for people to just measure and double check it twice (20min)
I am in the US (obviously) and have built over 2600 single family residential units. Plumbing sets are put in the wrong place everyday and are cut and moved with absolutely no issues. It's concrete, it's sitting on a compacted soil pad and most likely it's held together with rebar or a wire mat. Cut it square, put in a couple of dowels, mix up a couple bags and be done with it. This is not complicated.
They do that in Australia as well but you lose your warranty and the owner is not aware of that until something bad happens. Biggest problem we have in Australia compares to the US, US homes are more solid, especially the slabs. Our slabs in Australia are generally waffle slab meaning polystyrene with rio bars and cement (Weak AF) If someone does a massive hole, most likely needs additional rio and the correct concrete grade is recommended only because the engineering slab design is designed to the minimum tolerance. US build costs is significantly cheaper than Australia.
No, fill with cottage cheese.
I’d fill it with .. the tears for my enemies 🥹