Brickwork Articulation Joints

Brickwork Articulation Joints

So this is articulation joints. All right.
This is pretty important stuff especially, like, with cracks, I mean one
of the bigger things that we always seem to do is quote underpinning and you
know a lot of the time it’s not, you know, because of underpinning we want to make sure that the joints are there because brickwork does move, all right,
and you know I suppose what this whole the point of this is to
just some very brief knowledge on, you know, what is an articulation joint just
just grazing the surface. It’s not really getting too deep into it but based off
what the Australian standards are and what they actually are just to give a
brief overview when we when we are on site and when were looking at whether a
building has been cracking or you know even with the design process whether
we’re putting it in on plan which we’ve you know which we do for brick veneer
and double brick buildings. This focuses a lot on brick veneer because I believe
Queensland doesn’t do a lot of double brick buildings. In fact most new
construction isn’t double brick for a lot of reasons because of how
brittle it is. So brickwork is brittle. Obviously. It is quite evident when
there’s movement in the footings and so that’s why we provide articulation
joints, and articulation joints is allowing the movement for the brickwork itself based on a foundation movement so that we can allow the
foundations to move a little bit and we have directed the cracks to these areas.
Now you’ll notice you know that that’s basically what my first point is
covering you know why you know brickwork being susceptible. You know you find in
class “A” and “S” sites in the standards you don’t actually need to provide
articulation joints because if you’ve got a fairly sound soil you know
especially on sands or you know rock which is not going to move you don’t
need these articulation joints within a building course of foundations not going
to move. So it’s only on “M” through to “E” and “P” I suppose that we’re putting
articulation joints in the building and that will change depending on how
your design is and this is just a little little picture, a little graphic of what
it looks like which I’m pretty sure most would have seen where we’ve just got
the backing rod and then that sealant to make sure that there’s no water ingress. So as I saying footing needs to
move that’s why we need the joints and it’s all because of the foundation
movements. You’ll also find that you know temperature hitting or like very, very
much in Queensland and you know getting hot climates where you get an expansion of
the brickwork itself as well so that’s another reason we’re putting in control
joints. A little bit different to articulation joints but similar
premise that we’re allowing a section of the brickwork that we know is going
to you know allow movement to to basically stress relieve these areas
because of the heat and humidity and obviously it’s to reduce the cracking. So where do we put these joints? So if you look at AS4773 which is a sort of bastardized standard from AS3700 or you know the builders I guess code for for masonry
buildings or masonry for small buildings you’ll find this I think it’s in AS3700
as well but it gives you an indication of where we’re putting joints between the
joints yeah maybe putting the joints so you know I could go through this but
it’s it’s basically just a cookbook on where we’re putting the joints and you
know especially where we’re getting change in thickness to the brickwork
or change in height or the brickwork is where the differential movements going
to occur and that’s where we want to put the articulation joint. The articulation
joins usually about 10mm wide for single story or even up to about 8.5m
15mm for anything greater than that. Can be
combined with window openings. Yeah I mean if you’ve got a big window opening
there’s no reason why you can’t include that in your joint because the whole
point is you allow in the movement so if you if you’re putting an articulation
joint in you know the best spot is to put on the side of a window side of a
doorway so that you’re incorporating that window and the the change in change
in brickwork as well as the the moving of the soil so it’s it’s mad not to put
it near the windows. For control joints and things like that and
you know damp proof courses, this is something that I came across the other
the other day, putting joints and, well a damp proof course I
guess is the is the joint because it is a physical barrier or physical
difference between the bottom say 600
work and the above with the actual physical damp proof course so you don’t
have to continue you brick articulation joint through your damp proof course but
I think I do comment later on like the render what we have to do with render
but we’ll get back on that middle just some pretty pitches just because text
gets a bit old after a while so obviously there this is what I’m saying
about putting the articulation joint next to the window there’s your damp proof course. I’m not just yeah that’s so there’s nothing below there zoomed in
version that’s the sealant in there again not below the damp course
where there’s a change in height and brickwork we’ve got some an easy one to
see we’ve got different heights of brickwork so we’ve got an articulation
joint through there and this is a free-standing wall brick fence again
change in what the actual brick is doing possibly changing footings as well for
going from a house footing to a brick fence might be different so definitely
put articulation joints there. So how often in a standard building do we need
to put the joint in? Aagain from I think this is from AS4773 again or maybe it’s
from AS2870 or AS3700 don’t know no no AS4773 a lot of they all touch on it so you
know they probably all have similar tables so if we’re in a section so we’ll
go forward just for a second right so this is again a NS NS no articulation
draft required you can if you want not nothing saying your can’t put
articulation joints in but they’re more control joints for you your temperature
and things like that and that’s only if you’re getting large spans but in “M”
through to “E” sites this is what we’re sort of looking at his articulation
joints next to windows continuing through and when we’ve got a
section of wall right that has windows 900 x 900 we want to do them no less no
more than 5 meter spacing. Where we’ve got you know full brickwork then we
follow this standard so go to this section of brickwork which has got 900 x 900 openings we don’t go more than five hundred five meter so
section of wall that is doesn’t have 900mm x 900mm openings and we can go back to
that standard. Again if we’ve got massive openings you might want to put
it on each side of the doorway. Maybe there’s a picture after this. No.
Just consider for large doors that we might just put one on either
side and for class “E” sites we’ve got to be pretty pretty stringent on what
we’re doing with our joints and in, I think it is AS3700, they go through the
actual structural design and where to put articulation joints based on the
deflection criteria of the brickwork in the footings. I’ve never done it. That
sounds hard so yeah actually we’ll just go back a sec, Makes sense.
What we gotta keep in mind though is that if we’re putting a physical joint in the
building we still need to keep the structural integrity of the brick wall.
If we’re relying on a double brick wall to provide a shear wall or
some sort of bracing then we’ve got to make sure that we have consistency
through the brickwork and that’s where MET Ties come in. So these ties actually
physically move to allow the brickwork to move but they also hold the stability
of the wall so there’s different range of them. I’ve probably specified these
crimp ties more often than not but you know who knows if they’ll use them on
site you never really see it but we got to make sure that we’re pulling these
details on the plans and where we’re putting them I mean if this is a shear wall
supporting that wall we don’t want to physically separate that wall we want to
put our brick joint here or I think this standard says you can go up to 300mm away and this is this is the last sort of point I’ll bring up is that through
through rendering I mean other things you go to consider is that if you’re
rendering over joints you need to put a physical joint in that render as well
because again it’s a brittle brittle covering any brittle coverage that you
put on maybe it’s tiling maybe it’s render don’t know we’re gonna put a
joint where that where I put it articulation joint is because that’s where we’re directing movement. Probably not a consideration for us directly
but definitely something to consider I mean the other reasons we’re
getting cracking from foundations and you know I’m sure we all come across
this when we’ve done the crack inspections is adequate drainage from
from foundations. That’s why their footings move is that there’s
swelling contraction of the footings themselves. Trees causing change in
moisture conditions under the ground. Make sure the footings are actually sized appropriately in terms of AS2870 and the right type of house whether it’s
articulated brickwork or full brickwork or articulated brick veneer.
Make sure that that’s all done right and if we’re actually using block work
or reinforced concrete block our articulation joints can we
don’t have to have them as often. In fact I think you can get up to 12 to 16
meters without a joint because of how the the actual reinforcement changes the
ductility of the wall I suppose and it spreads that the stresses out over a
larger area so we get to include that. and that’s where I got all my info. That’s
101 of articulation joints and that’s it.

One thought on “Brickwork Articulation Joints

  1. I’m happy to find your YouTube channel, it’s YouTube itself that has recommended your channel to me.
    It is very resourceful and helpful for structural engineers in Australia.

Leave a Reply

Your email address will not be published. Required fields are marked *