Browse Forums Building A New House 1 Jan 31, 2023 4:11 pm Hi all, wish to here from you guys regarding my almost done new build's concern. Recently I noticed there are about 3-4 1mm horizontal cracks (about 2m each) between mortar and brick around the house in different spots. They are right under the weep holes and seem like happening on one side of the house than the other. Look like it cracks where brickies run DPC (I 'm not sure). My mortar is visually very sandy and brittle, so easy to be raked effortless. Consider the build is not done yet, is it a normal thing like house settling ... or a serious sign that I should seek further help? Cheers. Pics included Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: External brick wall has horizontal cracks around the hou 2Feb 02, 2023 12:31 pm This is normal. The first 2x rows are mortar on to concrete and mortar on to brick and is a strong bond. The DPC/Termite treatment is a plastic type produce and terminates roughly level with the face of the mortar. There is no bonding of the mortar to the plastic so you get a crack line. No need for concern We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 3Feb 02, 2023 12:39 pm BUT... the black vapour barrier under the slab is required to be brought up the face of the slab and terminate at finish ground level. Ask your builder how he intends to address this? as you will get water drawn by acpillary acting through the slab edge face into the slab. The spark arrester covers need to be removed so your weepholes work. And your gaps around the windows appear to be greater than the 2mm allowed for bushfire construction We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 5Feb 02, 2023 12:47 pm The DCP sits under the bottom plate of the frame, the first 2 rows of bricks start at the bottom of the rebate in the slab, the DCP runs under the frame over the cavity with slight fall to the top of the second row of bricks We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 7Feb 02, 2023 1:04 pm You have a number of issues being addressed at this location. Bricks absorb moisture (rain), the rain moisture rundowns the inside of the brick work and drains out of the cavity at the weepholes. The Cavity (gap) between the inside face of the brick and the outside face of the frame with paper over the top provides separation in the wall to prevent moisture bridging over to the frame. Quite often the slab edge will be totally backfilled so that only the bricks are visible coming out of the ground. Bricks suck up water so if they are incontact with the ground they will draw water up through the bricks. The DPC stops the upward movement of the water. The Moisture barrier sits on top of the ground (Pad) but under the Slab, its purpose is to stop water being drawn up through the ground and through the slab. Think of a tarp or anything, laid on the ground and the next day even without rain the underside is wet this is ground moisture. The moisture barrier is required to continue out from under the slab and up the face of the slab to stop water being drawn into the slab creating a wet edge. THIS water doesn't care about the DCP as it is being drawn through the slab in all directions. Hope this helps We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 8Feb 02, 2023 1:14 pm So if I cover slab edge and slab under frame with concrete waterproofing spray, most of the issues/problems with dampness through the slab should be resolved no matter wether the moisture barrier is fixed at the edge or not? Re: External brick wall has horizontal cracks around the hou 9Feb 02, 2023 1:35 pm Sort of but not that simple...sorry The BCA has what we refer to as DTS systems, like a recipe. You follow the recipe exactly you are all good. But the BCA also allows for smart thinking methods. Performance Based Solutions (PBS) this is where you can come up with new ways of doing stuff. The requirement is, that to use a PBS you must document a system that clearly shows it meets the minimum standard or betters it, set by the standard recipe. The issue is YOUR home insurance is only valid if the original built element is compliant with the BCA or an accepted PBS, otherwise your insurer will deny the claim as illegal work. (Your carpet gets mouldy and rotts and the plaster draws moisture up the wall..not covered). Most builders will simply waterproof the slab edge, but this doesn't meet the Performance Requirements of the BCA and is therefore non-compliant. Nice rabbit hole you've gone down! We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 10Feb 02, 2023 1:44 pm Well, from the perspective of BCA, certified waterproofing spray should be as good as any other waterproofing solution, e.g. plastic, bitum, etc? How exactly it is a new way? As far as I remember, BCA do not exactly specify what DPC/moisture barrier solutions should be used. Re: External brick wall has horizontal cracks around the hou 11Feb 02, 2023 1:56 pm The BCA states the vapour barrier shall be continuous. If you have a join (allowed) it must be a 200mm and taped. As the vapour barrier would have been cut back around 50mm outside the slab edge you would need to undermine the slab edge to lap and tape the join. So, simply waterproof the edge. No waterproofing product will stick to the vapour barrier (plastic). Oh and your solution must show it can last >20yrs. We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 12Feb 02, 2023 2:10 pm Waterproofing spray to be applied under the vapour barrier, not over it. And also can be used instead of DPC under the frame. But the best solution will be to waterproof whole slab for life during pour by adding waterproofing chemical compound. Re: External brick wall has horizontal cracks around the hou 13Feb 02, 2023 2:31 pm Hi, thank you all for commenting, look like I found the right one to talk to here. @buildingandlegal: I already mentioned the crack to my builder and they said that they will talk to the brickies to investigate. in saying that it is normal and no need to concern, should I ask the builder to patch/fill/fix... that in some sort? Just because hair line crack in total of about 6-7m around the house does not look very good. And do you do inspection service in Victoria? I really wish to have you look over my house, thanks Re: External brick wall has horizontal cracks around the hou 14Feb 02, 2023 11:46 pm Mate, sorry we currently do compliance inspections in NSW & Qld only. You can ask but as the DPC acts as a bond breaker the hair line crack will always come back. We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 15Feb 03, 2023 9:04 am If the "crack" is due to DPC nothing you can do about it. Mine was also like this. It's common sense you put a thin layer of plastic between brick and mortar that's what you get. Re: External brick wall has horizontal cracks around the hou 16Feb 03, 2023 11:45 am Yeah I get the idea but I personally have never seen any house with cracks on that spots. I did even try to find it on the houses around mine but they all look very solid, maybe just too soft mortar on mine. Re: External brick wall has horizontal cracks around the hou 18Feb 05, 2023 12:16 am The DCP is actually required to terminate level with or outside the raked or ironed mortar joint. This creates a true break in the wall stopping upward moisture movement. A lot of builder's brickies lay is short, where it terminates 5-10mm in from the outside face of the brick, then the mortar is raked/ironed with the DCP 5mm in from the finish surface of the mortar. In really wet sites this is a problem as the moisture break is breached. In most comon sites it is now 'much' of an issue. Pedro4137 is correct, the more reactive the sites soils the more movement the more the bricks move, the more evident the crack. We are Expert Consultant's, and we are here to help. Re: External brick wall has horizontal cracks around the hou 20Feb 05, 2023 11:58 am BuildingandLegal A lot of builder's brickies lay is short, where it terminates 5-10mm in from the outside face of the brick, then the mortar is raked/ironed with the DCP 5mm in from the finish surface of the mortar. In really wet sites this is a problem as the moisture break is breached. In most comon sites it is now 'much' of an issue. It is good to see this knowledgeably mentioned as several builders use a certified Performance Solution that allows the DPC to be 20mm short which goes against the brick manufacturers recommendation. There were a few discussions about this maybe 4-5 years ago that a forum keyword search should find. Unfortunately, aesthetics often subjugate function and Performance Solutions are sometimes used to mask poor workmanship. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Do I need to concern about this pattern of crack? Is this crack showing some signs of bigger problems? Thanks for any suggestions! 1 2225 DIY, Home Maintenance & Repair could be the footing or being hard up against the other wall with no expansion joint or both. You could try again with brick mesh and use some sticky back foam against the… 1 1870 |