A new one for the Home & DIY tools, this one checks whether your planned boundary wall is actually legal before working out what it costs.
Most boundary wall pages are either a lead-gen quote form with no numbers at all, or a bricks-and-cement calculator with no idea whether the wall you’re planning is even allowed to exist at that height. Nobody joins the two. This tool applies the actual SANS 10400-K deemed-to-satisfy tables, the rules that decide whether a freestanding wall needs an engineer’s design or not, for 110mm (half-brick) and 220mm (one-brick) walls, across all four pier arrangements the standard covers: no piers, piers on one side, piers on both sides, and a Z-shaped plan.
The headline finding that got me building this: a 220mm one-brick wall is right at the legal limit unpiered at 1.8m, the common street boundary height. But no thickness reaches a 2.1m lateral boundary, common under a lot of municipal by-laws, without piers. The calculator tells you the pier size and spacing the table actually requires for whatever height you’re aiming for, works per side so you can use different heights on your street and lateral boundaries, and flags a ground-level difference along the run too, since a sloping site quietly eats into your allowable height under the same standard.
From there it works out the full materials list, bricks, mortar, footing concrete, brickforce, plaster and paint, sourced from the same PPC and AfriSam figures already behind the concrete & mortar calculator, plus a plaster figure from the Concrete Society of SA that wasn’t on the site anywhere before. It finishes with a cost per metre you can sanity check against a contractor’s quote, and a printable materials list.
If you’ve built a boundary wall recently, particularly anything using piers or a Z-shaped plan, I’d be glad to hear whether the pier sizes and spacing match what you actually had to build to.
Ja this is a good one. Half the trouble round here isnt the wall itself, its people building whatever height they like and then fighting with the neighbour or the municipality after the fact. I put up 220mm brick on the plaas boundary years back, nobody checked pier spacing then, thing still standing but I was lucky I think.
Town plots are different story though, dis mos so that municipal rules and SANS specs actually get checked now. If this tells people upfront what pier spacing and height they legally allowed before they order bricks, thats gonna save a lot of kak arguments and wasted cement. Common sense stuff, just needs a tool to make it easy. Will pass it on to my neighbour, hes building now.
The part about no thickness reaching 2.1m unpiered is exactly what my neighbour found out the hard way last year, after her contractor had already started laying. eThekwini’s building inspectors are not lenient about this, and the retrospective engineering sign-off cost her more than the wall itself. Good to see a tool that flags the SANS limits before anyone starts mixing cement, does it account for eThekwini’s own by-law height restrictions on top of the SANS tables?
Good question, and that’s exactly the kind of story I built this to try and head off. To be precise about what it actually checks, the compliance side works off the SANS 10400-K national deemed-to-satisfy tables, height, thickness and pier spacing. It doesn’t know eThekwini’s specific by-laws, or any other municipality’s, since those sit on top of the national standard and vary by council.
The tool does flag this though, it notes that street and lateral boundaries often have different limits under municipal by-laws and tells you to check both the SANS table and your local by-law before you start. So it’s a solid first pass for catching the obvious mistakes, but your neighbour’s inspector story is a good reminder that the council’s own rules are still the final word. Worth a quick call to eThekwini building control before anyone breaks ground, especially for a street-facing wall.
That 1.8m limit on an unpiered 220mm wall is the kind of thing that would have saved my neighbour about R8 000 in wasted materials last year, he only found out the wall was non-compliant after the bricks were already on-site. The bit about no thickness reaching 2.1m without piers is going to genuinely shock people who have been copying whatever the house next door built without checking a thing. Good that someone finally joined the SANS compliance check to the cost calculation, because every other page online is one or the other and never both.
Ja that pier spacing thing catches out more people than you’d think. I’ve seen it on my own street, some boundary walls put up years back that would never pass now, but they’re grandfathered in so nobody’s touching them. The thing with unpiered walls is people think thicker brick just means stronger, full stop, but it’s the lateral wind load that gets you, especially up here where we get those southeasters that’ll rattle your roof sheets in summer. A wall with no piers acts like a long thin blade in the wind, doesn’t matter how wide the brick is, past a certain height it wants to topple.
Good that this tool makes people check before the bricks arrive rather than after, because moving piers around once the foundation’s cast is not a small job, you’re talking demolition and starting again. Only thing I’d add is get your foundation depth right too, seen plenty of walls crack because they skimped there thinking it’s “just a wall” not a structure. Sounds like a handy one for the site.
This is the thing that annoys me about most of these calculators, they tell you the cost and never tell you if the council will actually let you build it. Good that someone finally checked the SANS tables instead of just guessing. The 2.1m point is interesting too, means half the walls I see going up next to main roads around here are probably not compliant.
Useful that it actually checks SANS 10400-K instead of just dumping a bricks-and-cement list. In Cape Town the 1.8m street wall is what every builder quotes as if it is automatic, and nobody mentions you are sitting on the unpiered limit for a 220mm wall, especially with the southeaster slamming the same face for weeks. A 2.1m lateral wall without piers or an engineer is the bit that caught me out last time I priced one in Hout Bay, so if the calculator flags that before you order bricks it is already doing more than most municipal “guidelines” pages.