Concrete, weep holes and window sills

**Posted in another forum by mistake. Now in here for more appropriate audience**

Hi all. We had our concrete driveway removed and replaced several months ago. I'm only now getting an awareness of weep holes, and am seeking advice.
The new concrete is higher than the original level where it meets the house. What I suspect are weep holes are found at consistent heights all around the exterior, except for the concreted area, where they appear sit one course higher, immediately above the concrete. I suspect the actual weep holes are now covered by the concrete, and I can't explain the higher gaps in the mortar (I didn't inspect prior to the concrete job).

The concrete is also level with the bottom of the entry door threshold and the window sill tiles. This was not the case originally, whee there was at least a 90mm vertical distance.

Are any of these likely to be an issue, with water or movement? If so, What recourse might I have with the concreter? I've already paid in full.

Thanks in advance.

Photos of concrete at window sill:
https://imgur.com/a/rFq8tJO

Concrete at entry door:
https://imgur.com/a/6f3IcZc

Suspected weep holes:
https://imgur.com/a/gBKuMMI
REPLY

Did the 'concreter' claim to be a 'professional' trades person?

What State are you in and is any of it under a covered area?

Yes, he did claim to be professional. When asked about his licence, he stated it was not required for domestic jobs of this size. His associate who worked the job with him is apparently registered and insured.

We're in Victoria. Not covered, just standard eaves.

Hmmm. What he said is probably right depending on cost but he still has to work to compliance and having the concrete path less than 50 mm below the Damp Proof Course when not undercover in Victoria is a serious breach of compliance.

The 3 part National Construction Code (NCC) comprises the Building Code of Australia (BCA) Parts 1 & 2 and the Plumbing Code of Australia (PCA) Part 3. The NCC can now be downloaded free of charge. The 2016 edition will be updated on 1 May 2019.

The NCC 2016 (Part 2) 3.1.2.3 states:

"3.1.2.3 Surface water drainage
Surface water must be diverted away from Class 1 buildings as follows:
(a) Slab-on-ground — finished ground level adjacent to buildings:
the external finished surface surrounding the slab must be drained to move [i]surface water away from the building and graded to give a slope of not less than (see Figure 3.1.2.2)—
(i) 25 mm over the first 1 m from the building in low rainfall intensity areas for surfaces that are reasonably impermeable (such as concrete or clay paving); or
(ii) 50 mm over the first 1 m from the building in any other case.
(b) Slab-on-ground — finished slab heights:
the height of the slab-on-ground above external finished surfaces must be not less than (see Figure 3.1.2.2)—
(i) 100 mm above the finished ground level in low rainfall intensity areas or sandy, well-drained areas; or
[/i]
(ii) 50 mm above impermeable (paved or concreted areas) that slope away from the building in accordance with (a); or
(iii) 150 mm in any other case."


The above references to low intensity rainfall areas do not apply to Melbourne metro and most other parts of Victoria. I have used green to indicate the passages applicable to you.

The purpose of weep holes is to drain water, not allow its entry and retention. Low weeps holes are also an invitation to termites and other pests.

AS 2870 may reference a 75mm minimum height but I don't have access to that document or know if AS 2870 would apply to you. Others will pass on additional information I am sure.

Thanks SaveH2O. Having that excerpt from NCC is a big help.

I now have a slight step DOWN into the house when crossing the entry door threshold, so it's clearly not 50mm lower than the slab.

Time to get the concreter over for a little chat, I think.

Have someone knowledgeable about compliance with you for back up and as a witness. The concrete will have to come up, it can't be left like that. It is a terrible job and very hard to imagine that they were experienced.

Also check your Overflow Relief Gully (ORG) and post a photo if possible. It looks like a raised drain cover. If it is set in the concrete, do you know whether the 'concreters' raised it from its original height.

https://www.vba.vic.gov.au/__data/asset ... Relief.pdf

https://www.youtube.com/watch?v=9t3GgHsFZDk

The grate you see there is a pit that connects subsoil drainage (slotted PVC) to stormwater. It was installed some time prior and cut into the original driveway. It is now concreted into the drive; it's height was adjusted (cut and vertical slide the top) and was I assured the fall was not affected.
No overflow relief gully in this area as far as I can discern. Can post pic of pit later if you're interested.

That's good. You certainly don't want an ORG in the vicinity of low weep holes.

How about where it is in contact with the window sill tiles? Could that also be a potential point of failure?

The concreter has been over for a talk. He was rather non-committal, and blamed the levels on the local circumstances (required fall, nearby drainage pipes). He did acknowledge that the slots identified were likely weep holes and attempted to claim that covering them in such a way would have little impact, and that new builds are right up to the weep holes.
We didn't get around to really discussing a resolution (thanks to a toddler); he is reluctant to rip up and repour, and suggested a solution could be to cut strips in front of the weep holes and fill with stones to allow drainage.
We're not yet done discussing this, and I'm yet to go to town quoting the NCC and relevant standards, but that doesn't sound like a satisfactory solution to me.

I'd appreciate your thoughts. Thanks.

You have had non compliant work done by someone who doesn't appear to know the regulations and is not even sure what weep holes look like.

You should send him a non aggressive written summary of your conversation, ask him to verify it's accuracy and have all future communication with him in writing, preferably Email.

Termites also love easy access to moist dark woody spaces. Have you previously had termite protection done?

I don't think that the VBA can help you but you could contact them and ask and also ask them to verify the regulatory separation distance below the weep holes.

I think that V-CAT would be your only recourse save the concreter owning the responsibility for what he has done but that doesn't sound likely.

The thread below may be of interest to you even though the issue was the slope. Have you checked your path's slope away from the slab over the first metre? Regardless, the thread demonstrates how regulatory requirements cannot be argued against.

viewtopic.php?f=1&t=72769

Thanks very much for your speedy response, SaveH2O.
The slope is sufficient to comply with NCC 3.1.2.3 (a) if we accept that we are in a low rainfall intensity area - the ARI for the region given by AS/NZ 3500.3 indicates that we are. It would NOT comply should we be classified as not low rainfall.
I haven't had termite protection in the time that we have owned the place (4 years). I'd be surprised if the previous owners had either. Thanks for the prompt.
I did contact the VBA in the meantime. Their response only mentioned pursuing breach of contract and an official complaint, but we have some ways to go before we get there.

I asked about termite protection because the concreter would almost certainly have broached it if it was there.

The concreter probably thinks that he is on a hiding to nothing and has decided to dig his heels in. A lot do that.

He sure is digging his heals in. I sent the email as SaveH2On suggested, also citing the regulations and standards to which I believe the work is non-compliant (i.e. AS 3727.1, AS 2870, AS 4773 and the NCC). He visited a couple of days later to inspect and measure, and again to talk with me before I could insist that all communication be in writing.

His position is that he can't justify ripping it up and re-pouring (expected, as he has a vested interest). He acknowledged the regulations, but made clear that he thought that site conditions sometimes mean that they can't always be complied with. The rationale in my case was to account for fall away from the house and provide clearance above the pipes - we had installed by licensed plumbers many months prior to combat subsoil moisture (admittedly, I see that NCC does indicate that there could be some wriggle room there, but not to what extent)

He proposed blocking up the partially covered weep holes and drilling more higher to provide ventilation. He also suggested that should water enter through those partially covered holes, it would simply exit out another. This was all said while acknowledging he wasn't an expert in damp courses or brick permeability!

I left it at that. He had made his position clear. So far I haven't hinted at getting independent professional advice, but I kind of wish that I had asked if he was confident his reasoning would stack up against an inspector's report. Any way, time to get that report done.

Can anyone recommend an inspector with expertise in the Geelong area?

As an aside, the concrete is hard up against the window sill tiles (previously there was a one brick gap). I asked what what would happen if there was some movement in the concrete. His response was that the tiles might pop! I mean, seriously...

He sounds like a decent enough guy who has taken on concreting work without knowing the regulations applicable to his chosen trade. Unfortunately, this lack of regulatory knowledge has led to the work he did being substantially non compliant and there is no easy fix apart from removing the concrete. I would be very surprised if he was not a novice and he needs to learn from this. The second concreter also seems to have let him down.

Re weep holes, their purpose is to allow water inside the wall an escape route, they are not there for ventilation and having an impermeable barrier above the Damp Proof Course (DPC) doesn't allow water to escape. The regulations are there for a reason.

A building consultant can only advise you and not instruct the concreter. They also cannot instruct the concreter although given the concreter's lack of prior regulatory research, a report may be an inducement for him to enact a resolution. If it goes to V-CAT, a building consultant may also have to be prepared to attend as an expert witness (if qualified) to be of any use which would cost you more money and while V-CAT do take expert opinion seriously, the applicable regulations and photographic as well as other evidence when presented are things that the concreter could not dispute.

Building_expert is a serious contributor on HomeOne as well as being an advertiser, maybe contact him via his profile and ask his advice as to your best next step and the benefit if any of having an independent report.

A little update. The concreter has come to the party. Kind of.

I engaged a building inspector to provide a report. That report showed the paving to be defective with respect to the applicable regulations, and recommended that it be demolished and reconstructed at the concreter’s cost. It also recommended that I be refunded the difference between the contract (quote) price and the invoiced price.

I provided that report to the concreter and identified several infringements of the Domestic Building Contracts Act (relating to warranty, deposit amount, and contract price variation). He subsequently acknowledged the defective work, and admitted that the increase in price was due to his error in measurement.

He is prepared to remove the “non-compliant concrete just not the compliant part” and give a proportional refund. After several attempts by me to have him elaborate, he has not identified the boundary of the “non-compliant” and “compliant” areas of concrete (I expect he means the first metre or so from the walls). After removal and refund of that area, he would consider the issue resolved and walk away. He will not refund the difference in contract and invoiced price.

He expects that I would then engage someone else to reconstruct to compliance, and has suggested that I would need to modify the existing plumbing and add more drainage to achieve that.

He blamed the non-compliance on the location of subsoil drainage pipes. The pipes were present and accessible (pit at pipe junction, and trenches backfilled but not covered by paving) for measurement by the concreter at every stage prior to and during the job. My position is that he failed in his due diligence; he should have not accepted the job – or continued work - if he had identified that the position of pipes would result in non-compliant paving.

I have confirmed the building inspector’s opinion that partial removal and reconstruction would be visually unacceptable (unfortunately not explicitly written in the report). I also suspect that the excessive height of the remaining section of concrete (wherever and whatever that is..) would be problematic in achieving required surface drainage at the building.

The total job area is around 90m2, and I expect he may want to remove around 15m2. What do you think – would I be realistic and reasonable in pursuing removal and rectification of the entire job area?

The report is no surprise and the recommendation obvious.

Hmmm?

From your description, it appears that he considers the 'fix' to entail building a moat against the wall. Is the sloped concrete on otherwise flat ground?

If he hasn't put his offer in writing, could you send him a summary of your conversation along with a diagram of your perception of his intent and ask him to verify or otherwise detail further?

One thing that I haven't mentioned previously is that the role of the Damp Proof Course (DPC) below the weep holes is to prevent rising damp which can cause brickwork efflorescence and other problems. The link below gives more detailed information is is worth reading.

https://www.abis.com.au/defective-or-br ... oof-course


I have some sympathy for him as he has tried to work around the problem of the ag pipe being cut into the original driveway but he shouldn't have taken on or continued the work once the pipe's location was known. He needs to learn from the experience but what he has said is correct although the proper course of events would have seen the recommendation made and enacted prior to pouring the new driveway.

Reading between the lines, I suspect that he tried to save you further outlay to secure the work and I also suspect that he is new to the business by virtue of his volumetric miscalculation of required concrete and the lack of regulatory knowledge including the purpose of weep holes and DPC.

I assume that laying the ag pipe was made difficult by the original driveway.

Re-laying the ag pipe along its current course would depend on the current slope to the silt pit and from the silt pit to the Legal Point Of Discharge (LPOD) but if the downpipes drain to a LPOD, then the silt pipe almost certainly also would but this would need determination.


You are correct of course. You hired someone who you trusted to be professional in the execution of his duties and he also had a responsibility to himself and his business to deliver a compliant product. There are no winners here.


It would look ridiculous and would not satisfy what was originally agreed.

Do you know how close to the wall the ag pipe is?

The interim course of action would be to find out whether the ag pipe can be laid deeper and retain sufficient slope to the LPOD once the concrete is taken up.

I don’t believe he thinks that the “moat” is the end-point, but that it (plus the partial refund) is where his part in the total solution ends. After he is done, reconstruction would be my responsibility. The ground in this area is flat.



He has stated in writing that he will remove “non-compliant” concrete, but has declined to elaborate so I can’t be 100% sure I understand his intent. I emailed him a photo of the driveway, asking him to mark it up to indicate the area he would remove. His response (via email, mind you) was that he is computer illiterate and did not know how to do that. I’d say he is in his 30s, so find that difficult to swallow.

But yes, good idea, I’ll cack up a diagram.



The report documented what could already be signs of rising damp at the affected site. No efflorescence at this stage, however.



That and the other infringements of the DBCA that could see him hit with significant penalties if VBA choose to prosecute.



I’m unsure how difficult the slotted PVC was to lay, but do know that clay stopped them from going as deep as they wanted. The plumbers cut through the original driveway to dig the trenches, as we wanted the water issue addressed sooner and didn’t have a timeframe for driveway replacement. The outlet of the silt pit connects to the downpipe system.



Absolutely, but I’m unsure how I go about pursuing having the whole lot redone, based on its aesthetics rather than function/performance.



Good idea. I doubt there is much room to adjust the height of the pipes and pit, but would be worth having that assessed. Will reach out to the original plumbers first. The closest pipes are approx. 1.5m from house, from memory.

Ok, the ag pipe was buried under the original concrete driveway in a trench. I wrongly assumed from earlier text that it was encased in the original concrete.

The new driveway is higher yet you said in post 7 that the pipe is now encased in the new concrete. I can't get my head around how the pipe could have been trenched under the original concrete driveway but is now encased in the new higher driveway. Was the new driveway made thicker to cope with heavier vehicular traffic or was the old driveway thin and cracking?


Good idea, he will know and understand the situation and give good insight on the levels that the concretor had to work with. I would like to be there to hear what the plumber has to say about the pipe coverage under the original driveway.

Yes, ag pipe was laid lower than the original driveway. Attached photo shows the condition of that portion of the driveway prior to concrete job commencing. Concreter would have only had to remove some scoria in order to determine depth of pipes. Trench closest to house runs Ag pipe, the other runs the outlet from pit to join downpipes.


Unsure of original driveway thickness. It was badly cracked and heaved, apparently without mesh. The new driveway is 100mm thick (where measurable) and with mesh.

You're welcome to be present if you fancy a trip west!