Browse Forums Building Standards; Getting It Right! 1 Jan 19, 2015 7:09 pm Guys I have a question and after your expert opinions. ( my inspector has already highlighted it, just want to educate myself more)
My garage slab is below ground level because of my site cut which means the wall is a retaining wall. My question is this. The slab engineering says that a 90mm agg pipe needs to be installed - that's fine It also says use 230 thick double engaged brickwork where retaining. Does this mean that the bottom 4 (was 5 incorrect) coarses from the top of slab of my wall needs to be double brick? The wall only has supporting double brick pillars in parts. Below is an extract of the engineering and also a pic of the wall which shows it to be approx 5 coarses (375mm) retaining. The other thing is, if it is a retaining wall, is it ok to just mortar the bricks on top of the slab with no rebate? Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Garage retaining wall 2Jan 19, 2015 7:55 pm I generally specify 2c (230mm) Max height 6c HTH Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Garage retaining wall 4Jan 20, 2015 5:55 am Going by the information you have shown the brickwork work should be 230 wide ( solid double brickwork) up to a maximum height of 300 mm above your slab. Looking at the photo this is not the case , a photo showing the outside of the brickwork and levels of ground in relation to the property next door would help Re: Garage retaining wall 5Jan 20, 2015 6:24 am Hi Tim, the ground level of next door is the bottom of the fence plinth, which actually 3 bricks high from the top of slab. I think if they had to put double brick up 300mm it would look stupid in the garage don't you think? Does anyone have any photo's of such a thing? Re: Garage retaining wall 6Jan 20, 2015 6:36 am The engineering drawing you posted is not the correct detail because it is for an infill slab and yes there should have been a slab rebate. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Garage retaining wall 7Jan 20, 2015 6:40 am Oh BE...that' makes for a very interesting conversation with the builder then. I know this issue was highlighted on my inspection report, but I've still go no responses from the builder. Is there anywhere design guidance documentation that would say that you need to put a rebate under such circumstances? Re: Garage retaining wall 8Jan 20, 2015 7:00 am Corrrection to what I said You posted correct design detail because your garage slab was designed as infill slab and if you have a look there is a step down from garage slab to top of strip footing which would be equivalent to a rebate. Your builder has changed slab to monolithic without your consent and without giving you opportunity to review new detail. Builder should have submitted a new plan for your consent and then have it approved and stamped by BS As it is construction does not comply to approved plans not only in detail but also in levels. Where was building inspector doing mandatory inspection looking? Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Garage retaining wall 9Jan 20, 2015 7:10 am Hi BE, Just to clarify, Yes the slab was changed from infill to monolithic, however only upon my request because I believe it's better (be that right or wrong I'm old school) They did re-submit the engineering drawing to me, not sure about the BS, but it looks like they have not updated that detail in the drawings to be Monolithic with slab rebate. Looks to me like this is going to get a little messy. What are your thoughts on how to deal with a situation like this? Re: Garage retaining wall 10Jan 20, 2015 7:38 am The work is non-compliant and nor is the detail/construction carried out fit for purpose From what I can see the GL has been lowered next door approx 2c.. who's responsible for that? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Garage retaining wall 11Jan 20, 2015 8:02 am Crazyk Hi BE, Just to clarify, Yes the slab was changed from infill to monolithic, however only upon my request because I believe it's better (be that right or wrong I'm old school) They did re-submit the engineering drawing to me, not sure about the BS, but it looks like they have not updated that detail in the drawings to be Monolithic with slab rebate. Looks to me like this is going to get a little messy. What are your thoughts on how to deal with a situation like this? I have already made my findings and recommendations as below "Inspection Findings: 1. Builder is not maintaining surface drainage around the dwelling in compliance with engineering specification and there is a danger of slab edge flooding and foundation damage. 2. Levels indicate that the house slab has been built approximately 170mm below design level. 3. Serious issues are found in relation to garage wall soil retention of the adjoining property. 4. Timber posts are not secured to slab with galvanised post bases. 5. Excessively knotted timber has been used in studs and other framing members. 6. Braces are nailed too close to timber plate edges where fixing is suspect. Recommendations: 1. Builder’s surveyor to verify slab levels and report back to the owner. 2. If discrepancy in levels is confirmed, a conference with the owner will be required to resolve ground, drainage and retaining issues. 3. Builder to comply with engineering specifications and Building Code of Australia in all respects. 4. Builder to comply with the required site management of drainage and temporary downpipe requirements. 5. Builder to fix bracing and remove knotted timbers. 6. Builder to provide approved detail for post bases." We will have to wait for builder's response before deciding in next step, I think conference with the builder will be inevitable. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Garage retaining wall 12Jan 20, 2015 8:08 am StructuralBIMGuy The work is non-compliant and nor is the detail/construction carried out fit for purpose From what I can see the GL has been lowered next door approx 2c.. who's responsible for that? Sorry for my ignorance but does 2c mean 2 coarses? We didn't touch next door ground level. Below are a couple more photos before bricks and also from neighbours side. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Garage retaining wall 14Jan 20, 2015 9:30 am StructuralBIMGuy The work is non-compliant and nor is the detail/construction carried out fit for purpose From what I can see the GL has been lowered next door approx 2c.. who's responsible for that? Either way BE has a case and will need to provide calcs/verification to back up his recommendations Masonry Code AS3700 Section1.3 Use of alternate material and methods "Provided the requirement of section 2 are met, this standard shall not be interpreted in a way that prevents the use of alternate material or methods of design or construction not specifically refered to herein." Quote This is where an app would come in very useful Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Garage retaining wall 15Jan 20, 2015 10:26 am I think the builder will have to provide me with evidence that their "alternative solution" is adequate according to the standard. This is going to be the hard thing as the response times are quite slow considering I had my inspection prior to Christmas and it's now 3rd week of Jan. Re: Garage retaining wall 17Jan 20, 2015 7:16 pm Interesting that the starter bars have been removed from your updated drawing. Approx how high is the retaining part of the wall? Garage retaining wall 18Jan 20, 2015 8:38 pm RedHotMike Interesting that the starter bars have been removed from your updated drawing. Approx how high is the retaining part of the wall? Which Starter bars Mike? I'm blind The wall is retaining 4 coarses Re: Garage retaining wall 19Jan 20, 2015 9:33 pm Starter bars? What starter bars? You can't use them with double brick unless you core filled a cavity and made it wider than 230mm I'm pretty sure a slab rebate isn't required if the wall is being waterproofed. Speaking of which, good luck to them in doing that without someone spending a day on the shovel. Lets just hope the vapour barrier that's folded up is still in good nick Re: Garage retaining wall 20Jan 20, 2015 9:41 pm Well they can't actually get to the back of the wall because the neighbour has his concrete path there and there is only a small gap. I'm pretty sure the vapour barrier was cut off at slab height because it was still on the fence section they removed. Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5196 Thanks for the insights, that makes perfect sense, and yeah, I will be leaning on the experience of the excavator operator entirely. 6 16157 Hi All, I engaged a tradie to install concrete retaining wall 600-800mm high over 32 meters in Victoria. Sleepers are 200*75*2000 mm installed over 17 steel posts. I… 0 6917 |