Page 1 of 3
This is my 2nd home but first attempt and owner builder. I will upload my journey as i go along. i will also post my tradies details ( depending if they did a good job to help others out there ) Have friends and family in the industry to help me along.
The Project:My block of land has a 3 metre fall from front to back so we have gone with a split level house. 3 levels. Entry level which is street level. Garage and theatre room which i will be making into a golf sim room. 2 metre drop edge beam which gives us the lower level... then we have 5 steps going upto the upper level. Materials i will use i will post later once i commence.
House DesignMain LevelGround LevelUpper LevelContacts:Architect : All Image Architects ( Michael Yousef )
Contact: 0414326878
Email:
michael@allimagearchitects.com.auEngineer: Palitha S Wijesena & Associates Pty Ltd
Contact: 0404047161
Email:
psw888@gmail.comProgress: Sept - Plans Drawn Up ( attached photos )
Nov 7th 2018 - Lodged to campbelltown council
April 22nd - Coming up to 6 months in campbelltown council. I got hit with the worst apple in council. I would recommend if your in the campbelltown area avoid going through council and get yourself a private certifier.
28th May 2019 - Da And CC Passed through council.
30th May 2019 - Permit Granted.
3rd June 2019 - We start excavation
1st day excavation.
13 loads of dirt gone.... 20 more to go
keen to see progress looks great
Day 2 excavation. Internal drop Edge beam done. Alfresco cut. Nearly done
Half the piers down. Should get them all done tommorow
Let's start formwork. Weather has killed us the last week.
We have started building the great Wall of China. 1.85 metre drop edge beam formwork
That is going to take some crazy bracing.
It will be interesting to see.
That is going to take some crazy bracing.
It will be interesting to see.
Yep your right we got 1 full day of just bracing the wall.
Just out of interest. Are you planning on doing a continuous pour, drop edge and lower level in one go?
Just out of interest. Are you planning on doing a continuous pour, drop edge and lower level in one go?
We do the drop edge in intervals. Fill and start from the front. Once it sets we fill again and so on
Was actually meaning the lower level slab.
Typically you would pour the lower level slab leaving starter bars, then do your steel reo and build the formwork on top of the lower level slab. That way you have a solid surface to form up from and brace too.
It looks like you are forming up so you can pour the lower level slab and the drop edge in one go or at least the drop edge first.
In which case I am interested to see how you are going to hold it and brace it.
From what I've been told they will use accelerator in the concrete for the wall. Pour that in sections. Start from the top level to meet the drop edge. Then go from the alfresco on bottom level and work upto the drop edge so it drys in time.
Bracing done. Slab going down tommorow. Hope all goes well
Sorry, is there an upper level slab at the top of the drop beam (which is in fact is a slab-supported retaining wall)?
I am struggling to understand how exactly it has been waterproofed, as at this height it needs to be properly waterproofed (not just with a thin layer film, they cover it with bitumen type substance first, then with the waterproofing rubber-like sheets and then also put in geo-textile towards the backfill side), with aggregate drainage installed and connected with your stormwater. Otherwise, you are going to have serious issues with the dampness at the lower level.
Also, once waterproofed from the other side, the wall needs to be backfilled with the blue metal (20 mm gravel), properly compacted, with compaction levels being tested by the certified lab (as your upper level footings will be pretty much dug in the compacted area).
You can, actually, pour lower level and the wall in one go, but then the upper slab needs to be poured later with the bracing still on and with proper bent reinforcement bars, so the upper and lower slabs provide additional support for the retaining wall.
Ideally, the wall also needs to be insulated too.
My house has very similar design, so this is exactly how it was done - 2 pours with waterproofing and compaction in between.
Also, how exactly they will be pouring lower slab when there are braces on top? You still need to keep braces in place for a while after the pouring is done.
Sorry, is there an upper level slab at the top of the drop beam (which is in fact is a slab-supported retaining wall)?
I am struggling to understand how exactly it has been waterproofed, as at this height it needs to be properly waterproofed (not just with a thin layer film, they cover it with bitumen type substance first, then with the waterproofing rubber-like sheets and then also put in geo-textile towards the backfill side), with aggregate drainage installed and connected with your stormwater. Otherwise, you are going to have serious issues with the dampness at the lower level.
Also, once waterproofed from the other side, the wall needs to be backfilled with the blue metal (20 mm gravel), properly compacted, with compaction levels being tested by the certified lab (as your upper level footings will be pretty much dug in the compacted area).
You can, actually, pour lower level and the wall in one go, but then the upper slab needs to be poured later with the bracing still on and with proper bent reinforcement bars, so the upper and lower slabs provide additional support for the retaining wall.
Ideally, the wall also needs to be insulated too.
My house has very similar design, so this is exactly how it was done - 2 pours with waterproofing and compaction in between.
Also, how exactly they will be pouring lower slab when there are braces on top? You still need to keep braces in place for a while after the pouring is done.
Ok this is a reply from my concreter...
Firstly the black plastic film that goes under a concrete slab has already been engineered to stop moisture from seeping up from under ground it has been used for other 25 years and not a problem has occurred since the invention
The water proofing your talking about is for retaining walls where they have to use a substance and then they lay a black plastic sheet, the purpose of the black plastic sheet isn't waterproofing it's actually so stop the rough edges of the blue metal from scratching the waterproof liquid substance. This is not a typical landscaping retaining wall it has different details to landscaping retaining walls, our engineers have had geotech reports and also have experience in not just residents works but also commercial like Highrise buildings.
Second pouring in two seperate pours also takes a lot of strength away from the slab because between the two joints of concrete (old&new) you will have a weak point and any weight on that weak point will have consequences on the entire slab, not just that if any gaps are not filled in perfectly and any steel is exposed you will have concrete cancer will once it starts you can not tell how far it's spread through the slab which means you'll need to rip everything up and redo it all over again.
Pouring the drop edge beam with 3% accelerator means we can pour the wall and whole slab in one heat you pour 1/4 of the wall and go onto a different part of the slab and then the following truck pour 1/2 and so on until most of the bottom slab is complete and the accelerator has done its job by making the lower part of the drop edge beam go off quicker which means bracings can be removed with no affect what so ever.
The wall does not need to be insulated, insulated is to keep a temperature at a constant level if it was insulated the only purpose it would be for would be to keep the ants underground warm. If you like to see how we do it come tomorrow at 7 and watch actual Concreter's who aren't trying to make complications and charge a customer more money for separate pours work