The Rules of Masonry Design - Insights from a Structural Engineer

[@TweetyBored77]

As a recently graduated engineer I really enjoy your videos. Do you mind doing one showing your process of designing a building (maybe something small and residential). I’m curious to see structural plans/details and how you follow load paths etc.

[@BrendanHasty]

Hi Shae, I have plans for a video on this later in the year. Hope you enjoy it.

[@iamsameerkhandaker6585]

oh mate I wish I found your channel sooner! I am also based in Melbourne currently looking for an internship and watching your videos inspires me even more, thank you and best of luck for the future!

[@BrendanHasty]

Hi thanks for watching and goodluck on finding your internship.

[@DeepakKrishna11]

Nice to see your videos evolve in style. It is soo good to see explanation with outdoor real life examples. I have not seen a video discussing characteristics of brick work this deep. Keep it up Brendan.

[@BrendanHasty]

Hi Deepak, glad that you enjoyed it. I loved making this type of video will need to make more.

[@michaelbeck402]

Your recommendations are spot on. Our engineering company is often called upon to determine both why a failure exists in the structure and how to go about solving the problem. Would be far better to have the architect (or residential designer), builder and masonry worker to follow the engineering guidelines to preclude the problem. The builder often defers to the 'brick guy' without proper oversight. Water intrusion both on the brick and on the structural elements behind the brick are often the problem. The open pore house wraps exacerbates the problem. Wood expands quite a lot and puts lateral pressure on the brick. Lack of steel ladders or rebar bond beams in tall walls happens frequently. The majority of 'masons' today are not the skilled practitioners of previous generations and are 'allowed' to regularly cut corners. We primarily practice on residential structures. We see so many failures due to poor building practice. Poorly compacted fill under a footing to support the brick moves (due to weight or water or both) and the cracking and splitting begins is too frequent. Undersized lintels, lintels which are not properly attached to a support beam or header are often seen. Your video is compelling me to look for or develop a brick work guide to be followed on projects which would be a part of the shop drawings inspection (and field inspections along the way would be useful). Closely looking at the elevations and marking up where proper joints should be utilized, size and connection of lintels, waterproofing protection, etc. makes sense. These are areas we are never asked to provide guidance on. Whether facade or load bearing brick wall construction, much of the brickwork here is not correct. Thanks for another well done (and provocative) video!

[@BrendanHasty]

Hi Micheal thanks for the detailed response much appreciated. And glad that you found similar concerns. So many places where if poorly detailed can cause issues.

[@PeterDebney]

Hi Michael In the UK we are expected to specify lintels (some call them lintols) and movement joints. They MJs are too important to both engineer and architect to leave to the builder. We might also need to specify windposts where needed. Regarding brickwork guides, the UK brickwork associations used to produce them for here. I expect that the modern equivalents are still available and could be adapted for your market.

[@PeterDebney]

I was interested to see the recommendation for 6m spacing between movement joints. In the UK 6m is the spacing for concrete masonry, while for clay masonry it is 12m. Apart from thermal movement, clay bricks tend to expand after laying as they absorb water, while concrete blocks shrink as they dry out.

[@BrendanHasty]

Hi Peter, I would think the UK 🇬🇧 would have better knowledge on masonary. Interesting to hear the differences.

[@PeterDebney]

@@BrendanHasty my masonry knowledge is a little rusty, as it were, but I did do a quite a bit in a previous job. It sounds like NZ bricks are a different size to UK ones, which is not surprising as they tend to vary between most countries and also over time. In the UK they are now standardised at 9”x4”x3” with a 1/2” mortar joint, though now we are metric (50 years and counting) they are 215x102.5x65mm with a 10mm joint. This has the advantage that you can lay them multiple ways and they will join up without cutting them. This also means that they lay the same with the concrete blocks at 440x215x(various thicknesses). Most houses are brick and block construction but for larger buildings masonry is just used for cladding. There is some discussion over a return to lime mortar, which is more flexible than cement mortar and self-heals cracks, but takes more skill to work with. I would be interested to know the difference in carbon footprint between the two options. Does lime mortar ever get used in NZ masonry?

[@101bennyc]

Your channel continues to get better and better, thanks do making such useful and digestible content. 👍🏻

[@BrendanHasty]

Thanks Ben glad that you enjoyed it.

[@ldnelso2]

This is good stuff man!

[@BrendanHasty]

Glad you enjoyed the video mate!

[@richardaskham2154]

Aren't those cut bricks in the corner called Queen closers, and are used to keep the bond staggered in English or similar bonds?

[@BrendanHasty]

Hi Richard as they are less then half a brick they are Queen closers. 👸 they are only needed it your wall does meet typical brick unit lengths

[@richardaskham2154]

@@BrendanHasty yes, but if you are using say English bond and you are placing stretchers over headers then you need a quarter brick to obtain the staggered bond. I have worked with some very good bricklayers and seen this done many times. For example if a wall was 20 stretchers long then you would place 40 headers on top, but unless you want the perp joints to line up vertically then you need 39 headers and two queen closers to obtain the bond surely? Ps I like your channel I wish I'd found it when doing my degree last year.

[@dykodesigns]

When it comes to materials, in europe we also use a "synthethic" type of sandstone which is called calcium silicate. It's a mixture of lime and sand, bonded under high atmospheric pressure in an autoclave. It's colour is typically white and it's mainly used for structual walls (typically the inner, load bearing leaf of a cavity wall system). Nowerdays it's often glued with thin bed mortar joins. Are you familiar with this material?

[@BrendanHasty]

Hi DYKO, I haven't used it before sounds interesting I will need to look into it.

[@tlangdon12]

It's also referred to as Aerated Autoclaved Concrete or AAC. It's an interesting material, with similar properties to other masonry blocks (e.g. it cracks), but is generally lighter (so the blocks can bigger) and has better thermal properties. It can be more difficult to get a good fixing into, but there are special fixings that work well up to a point, and then resin anchors are needed for higher loads.

[@Pancake8274]

Sir thank you for your hardwork.

[@BrendanHasty]

Hi caveman, thanks for watching

[@taimoornaseem5866]

Brilliant video Brandon, Hard to grasp how the flat lintel can behave like arch. Isnt only difference the tension strain path is at an angle perpendicular to brick orientation instead of relying on mortar bond?

[@BrendanHasty]

Hi taimoor it is the angle of the brick installed causing compression.

[@PeterDebney]

Hi Taimoor I agree that flat arches do not look right at first but their mechanics are sound. Masonry is essentially compression-only so there is no tension strain path. Bricks do not work like elastic materials such as steel and concrete. Instead the trapezoidal shapes of the bricks in the flat arch means that they cannot move down without pushing out and hence arch. This effectively forms a compression thrust line which curves parabolically into the masonry either side of the opening. This works as long as the flat arch is deep enough. There is a classic book on masonry design called The Stone Skeleton. It is well worth a read.

[@taimoornaseem5866]

@@PeterDebney Thank you Peter for the detailed explaination. I get it now, So basically lines of brick orientation are the line of forces and trapazoid makes it an arch creating hz reaction at support thru moment equilibrium, no wonder why its hard for modern engineers to understand classic but simple and effective techniques. I will definitely refer to the book too. Thank you again.

[@TonioCartonio619]

Loved the video and loved the topic (it's the last course I've attended at university xD) I'd love to see more about masonry structures, it would be super insightful Keep up the good work

[@BrendanHasty]

Hi Tonio, thanks for the support. Loved making this video too got to fly my new drone too. Definitely will need to do more on masonry

[@edwaterengineering696]

Awesome footage! I actually did a transformation project at the queenscliff fort army base a couple of years back! There are some impressive underground tunnels there as well which they used in the war. Maybe something for your next video? :)

[@BrendanHasty]

Hi Ed, thanks for the support. That sounds like it would be an amazing topic will need to look into if they would let me film them

[@swarnangshughosh7532]

Hi! Great video as usual. Could you make a video about offshore structural engineering?

[@BrendanHasty]

Hi Swarnangshu, I will need to look into offshore structure and add it to the list.

[@amanmaharjan4997]

Hey Brendan, I'm Aman and I am about to finish my bachelors in civil engineering, I'm from Nepal and am thinking of taking on training programmes there in Australia to help familiarize with the techs and stuffs that Australia uses which Nepal doesn't offer, can you help me?

[@BrendanHasty]

Hi Aman, looking into getting charted, IstructE is a great parth, tho it is a hard exam. Tech every compainy is different. The biggest difference will be the design standards

[@samdr6387]

hello sir, i really wanna ask a question i hope i get an answer ....do i have to be theoretically very knowledgeable so i can study structural design engineering or we can use only softwares without doing calculations with hand? because i have a big lack in theoretical things. thank you

[@BrendanHasty]

Hi sam you need to do the hand computations, software can be wronge and modelled in correctly so you need to able to assess if it is correct.

[@yousifelsiryousif6487]

Ok nice Brendan hasty My doctor give my a home work on reinforce masonry buliding Where i can find refercne Please

[@civilideas1925]

👍🏻

[@BrendanHasty]

Thanks for stopping by!

[@ayadjasim9911]

Benefit culture.. in Arab countries begin steel structure residential building therefore the Arab engineers need knowledge in S.S .. we hope make culture in Thumb rule S.S multi story building more 10 story .. Thx a lot

[@BrendanHasty]

Hi Ayad, I have a video on the rules of thumb of steel design which should cover most situations.

[@George.Coleman]

Talk slower