Browse Forums Building Standards; Getting It Right! 1 Jul 27, 2015 2:02 pm Hi All, I have a question regarding the height requirements of weep holes. Background information: We are at the final stages of our house build. It is a brick veneer home on a concrete waffle pod slab. Originally, we requested the step down to our portico to be reduced from 150 mm to 63 mm to match the garage. This was not reflected in our drawings but we spotted it before they had poured the slab. The builders solution was to just raise the height of the concrete in the portico area by boxing it up higher which they provided us with a building variation with. Recently, whilst looking at options for flooring in the area I spotted that the DPC and weep holes are on the slab floor. This area is under the portico which is covered with 450 mm eaves around. My understanding based on what I have read in the BCA (Referred to AS 3700) is as follows; The height of the DPC or weep holes must not be less than 150 mm in areas where there is adjacent land (Soil etc...) to protect for ground movement. It can be reduced to 75 mm in areas where there is concrete/pavement that slope away from the wall. It can also be reduced further when protected by a carport etc... It also states that in South Australia they can reduce the level to 0 mm if it is protected from weather by carport, verandah etc.. Unfortunately, our weep holes are at almost 0 mm above the finished floor level. Does anyone know if this is an acceptable scenario? I don't have access to AS 3700 but I am hoping there is a clause in there that allows this. Otherwise, we are going to have to get it rectified. More delays Thanks in advance. Re: DPC and weep hole height 2Jul 28, 2015 11:17 am Minimum clearance is 75mm Obvious they didn't think about this at time of build Re: DPC and weep hole height 3Jul 28, 2015 11:34 am wood bang Minimum clearance is 75mm Obvious they didn't think about this at time of build Thanks wood bang... Apparently not. They have followed the DPC level on the face of the house around to the portico. Can they have different level DPC in different areas? Wouldn't there be a gap at the point of overlap? Cheers Re: DPC and weep hole height 4Jul 28, 2015 1:43 pm That is the reason why you initially had a step down of 150mm, when you asked for it to be reduced sales person should of informed you that this will be an issue, but he is a sales person how would he know. This is a common no-compliant issue for most project homes i see around. DPC can be stepped up or down, but in your case NO, because then it would be higher then slab level and any leaks from DPC would go to your internal floor coverings, and that wouldn't comply. The only solution is to remove that second slab. Re: DPC and weep hole height 5Jul 28, 2015 3:02 pm veseli That is the reason why you initially had a step down of 150mm, when you asked for it to be reduced sales person should of informed you that this will be an issue, but he is a sales person how would he know. This is a common no-compliant issue for most project homes i see around. DPC can be stepped up or down, but in your case NO, because then it would be higher then slab level and any leaks from DPC would go to your internal floor coverings, and that wouldn't comply. The only solution is to remove that second slab. Actually believe it or not it was the Slab Supervisor that suggested this change. Don't get me started about him... moving on. That is not a second slab. That is part of the house slab Builder is looking into it, will give an update once we know the final answer. Shockingly I found another member on this forum who built with PD that has the exact same issue. Unfortunately, he's been in the house for a while and probably doesn't know. Surprised he got the certificate of occupancy. I only noticed through the photos on his blog. Re: DPC and weep hole height 7Jul 28, 2015 6:10 pm Liliana joea Surprised he got the certificate of occupancy. Are you kidding me! Sorry joea but I've become very cynical about building surveyors and what they will notice or care about. I wish I was... I personally think it won't be a performance issue as long as we don't block them but technically it's a defect. Re: DPC and weep hole height 8Jul 29, 2015 11:11 am This shows a slab at the perimeter and why you should leave 75mm clearance as termite protection but the principle is the same as it shows the weepholes and flashing placement. http://i1212.photobucket.com/albums/cc455/stewiesno1/Slabtermitebarrier_zps8e505a80.gif The lower slab or rather the finished surface should not be higher than the horizontal part of the DPC and/or the lower part of the weephole otherwise water will pool there. Raise that external floor too much and water will find its way inside your house. Stewie Re: DPC and weep hole height 9Jul 29, 2015 1:19 pm Stewie D This shows a slab at the perimeter and why you should leave 75mm clearance as termite protection but the principle is the same as it shows the weepholes and flashing placement. http://i1212.photobucket.com/albums/cc455/stewiesno1/Slabtermitebarrier_zps8e505a80.gif The lower slab or rather the finished surface should not be higher than the horizontal part of the DPC and/or the lower part of the weephole otherwise water will pool there. Raise that external floor too much and water will find its way inside your house. Stewie Thanks for that information! It's really a weird situation with leaving 75mm of the slab exposes and providing concrete apron around the house. There's no way you can do both really. Re: DPC and weep hole height 10Jul 29, 2015 3:09 pm I think you misunderstand the context of that drawing. It was posted mostly to show the heights of the slab, the rebate for the bricks plus the position of the weepholes and DPC. That picture illustrates how you would do a non-chemical termite proofing to the perimeter of a BV house. Quote: It's really a weird situation with leaving 75mm of the slab exposes and providing concrete apron around the house. There's no way you can do both really. Yes there is. Either... 1) Pour both slabs all in one so there is no break between the two. Then you don't need any termite proofing between the two of them. 2) Pour them separately and if you want the outside level close to the inside floor level ( allowing for DPC and weepholes etc ) you need to have some other form of termite proofing at the junction of the two slabs - termimesh etc. All it takes is a bit of foresight from the builder and for the client to choose what they want as the finished surfaces. Stewie Re: DPC and weep hole height 11Jul 29, 2015 3:36 pm Stewie D I think you misunderstand the context of that drawing. It was posted mostly to show the heights of the slab, the rebate for the bricks plus the position of the weepholes and DPC. That picture illustrates how you would do a non-chemical termite proofing to the perimeter of a BV house. Quote: It's really a weird situation with leaving 75mm of the slab exposes and providing concrete apron around the house. There's no way you can do both really. Yes there is. Either... 1) Pour both slabs all in one so there is no break between the two. Then you don't need any termite proofing between the two of them. 2) Pour them separately and if you want the outside level close to the inside floor level ( allowing for DPC and weepholes etc ) you need to have some other form of termite proofing at the junction of the two slabs - termimesh etc. All it takes is a bit of foresight from the builder and for the client to choose what they want as the finished surfaces. Stewie Sorry I misunderstood. Ignore that entire post. I thought you meant we need to keep a 75 mm gap so that the termite pipes (chemical) can be inspected. I read that somewhere else too. Re: DPC and weep hole height 12Mar 28, 2018 7:29 pm [quote="fedup1"]I have very little faith in building surveyors to do their job these days. Our surveyor did not even attend site to inspect the concrete that our builder had poured and signed off anyway /quote] There are alternate Solutions Generally they require proofs and they are certified as equivalent or better than what is required in the codes Solutions affecting the structural Integrity will need to be assessed & Certified by Engineers You should have taken photos yourself, unfortunately now you are up "Ship Creek and Aami isn't there to help" should anything go wrong. This has been discussed many times...Goodluck Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: DPC and weep hole height 13Mar 28, 2018 8:23 pm StructuralBIMGuy There are alternate Solutions Generally they require proofs and they are certified as equivalent or better than what is required in the codes Performance Solutions only need to be certified by one 'expert' as satisfying the NCC performance requirements unfortunately, not very often do they meet let alone exceed the referenced codes. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: DPC and weep hole height 14Mar 29, 2018 8:56 am Glad to hear you are getting your issue sorted fedup1. Building surveyors don't notice much and even less when they don't bother to turn up. If you are in Victoria I would urge you to lodge a complaint if you have proof your building surveyor didn't attend the site to check your slab. On some builds, including mine, building surveyors get paid for doing nothing more than putting their stamp on bits of paper they haven't bothered to look at properly. Re: DPC and weep hole height 15Mar 29, 2018 8:57 am You don't need to convince me it's been sorted, convince your insurance company... should you put in a claim ...Get it aami Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: DPC and weep hole height 16Jul 11, 2018 7:25 am hi guys, if you can help me that will be great. I am getting my first home build and the weep inserts are bit higher than the usual height. they suppose to be on a second brick from the slab but its on the third brick, does it causes a major problem, if so how can it be rectified? Re: DPC and weep hole height 17Nov 21, 2018 5:32 pm sammy8888 hi guys, if you can help me that will be great. I am getting my first home build and the weep inserts are bit higher than the usual height. they suppose to be on a second brick from the slab but its on the third brick, does it causes a major problem, if so how can it be rectified? Check your engineering drawings. The important thing is that your internal floor level is HIGHER than your DPC/weephole bottom. Typically with concrete slab houses, they can’t afford to have 2C brick then DPC as that will mean much deeper edge beam but It can be done but more expensive. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: DPC and weep hole height 18Mar 05, 2022 9:05 am OK - great to hear that weep holes are a big issue (except when it's your own problem) because we have a problem as well. We have a sunken lounge room on a concrte slab that is some 250mm lower than the rest of the building. The base brick course of the weep holes are 230mm above the lounge room floor level. Twice now this floor has been flooded after massive rain events (including last weeks) and the water seems to be coming in through the weep holes. On the outside of the building the ground level is only about 80mm below the base of the weep holes. My question is should the occurence of water entering the lounge room be solved if I can lower the ground surface to at least 150mm below the base of the weep holes and drain it away or do I need to go deeper below the lounge slab floor level? interesting situation what happened after builder issued final invoice? did you list as defect or not does the building surveyor have any responsibility? ie. issuing… 13 46966 You are correct. Just read through all the ncc rules and 75mm is the minimum requirement for me. 4 11183 it depends on the natural ground level, if they excavated their boundary wall needed to be built as a retaining wall. If you filled, which sounds like the case then you… 1 7086 |