Brick quantities for various bonds
Richard
On page 13 it shows various bonds. Every one except one is a brick
thick. Bottom right gives quantities of bricks for one square meter of
brickwork, a half brick thick.
Question: Why have they quoted quantities for a half brick thick, when I
presume, in practice, nobody would build those bonds a half brick thick,
(except stretcher bond)?
Would it not have been better to give figures for a brick thick wall?
Thanks.
harry
> http://www.ibstock.com/pdfs/guide-to-good-practice/bwk-good-practice-...
>
> On page 13 it shows various bonds. Every one except one is a brick
> thick. Bottom right gives quantities of bricks for one square meter of
> brickwork, a half brick thick.
>
> Question: Why have they quoted quantities for a half brick thick, when I
> presume, in practice, nobody would build those bonds a half brick thick,
> (except stretcher bond)?
>
> Would it not have been better to give figures for a brick thick wall?
> Thanks.
Half a brick thick is100mm. A "brick" in this case is considered to
be the length of the brick ,not the width if yo usee waht I mean.
Dunnowhy they do this,hallowed tradition I suppose.
The number of bricks required is not effected by the bond,only the
area and thickness of the wall (ie volume)
Richard
Yes, a single brick wall, (now called a half brick wall) would be about
100mm wide. A brick wall is as deep as the length of a brick, about 215mmm.
It seems to me that to get the correct quantites for a wall a brick
thick, you have to double them. So, the make a one meter high, one
metre long brick thick English bond wall, requires 172 bricks. But, if
you build the same domentioned wall with Flemish bond you only need 154
bricks.
Now the volume would be the same, and if that is the case you must use
more mortar. So, would you save money in the end bulding Flemish bond?
Richard
http://www.ibstock.com/highlights-brick-calculator.asp
You see, on the brick calculator, that if I did that the area is exactly
1 square metre. You also see that it would take 60 bricks. That tallies
with the brick quantities on page 13 of Ibstock's Guide to Good Practice
cataligue.
What I understand is, that if I built the same wall, 5 bricks long and
12 courses high, but English bond, I'd use 86 bricks. Or, Flemish bond,
77 bricks.
But, if I use less bricks, because I choose Flemish over English bond,
say, I must use more mortar. That's what I think is the case. If mortar
is more expensive than brick, it would be more expensive to build with
less bricks.
Or, am I making a mistake somewhere?
Richard
One thought. Should it not take exactly the same number of bricks to
make any half brick wall, 5 bricks in lenght and 12 courses high? I
think so, because the area is the same.
Is the catalogue saying that you would need to BUY 60 bricks to make a
half brick stretcher bond wall 5 bricks in length, 12 courses high, and
you would need to BUY 86 bricks to make the same wall will with English
bond?
John Williamson
Possibly. We always used to order the same number of bricks for a 215mm
thick wall, no matter what the bond, ignoring minor stuff like chopping
bricks in half for odd sized holes and corner bonding. The calculator on
the page is for 102mm thick walls assuming that for each header, you use
a complete brick, throwing away the other half brick. There may be an
allowance in their calculations for spoilage when the bricks are cut.
For 215mm thick walls, it's about 120 bricks per square metre when you
order them. For 102mm walls, it's about two thirds of that, due to
wastage when cutting to make short headers. The bits that get cut off
normally end up filling the bottoms of trenches as hardcore.
The other thing is, you don't build brick walls to exact metres, you
design and build them to multiples of 112.5mm horizontally, with 10mm
allowances for mortar joints being missing at the ends, and 75mm
multiples vertically, with 10mm allowance for the missing mortar joint
on top.
--
Tciao for Now!
John.
dennis@home
"Richard" <no...@ntlworld.com> wrote in message
news:95j7gl...@mid.individual.net...
A full brick would be a 9" thick wall as built pre cavities.
A half brick is 4.5" as per a single leaf of a cavity wall.
Its easy enough to remember 50 bricks per sq yard and double it for a double
wall.
(all sizes tend to be metric now and are a little bit smaller)
Richard
I just drew out two walls, both 5 bricks in length and 12 courses high.
In area both 1 square meter (5 bricks long, 12 courses).
Here are my results:
STRECHER BOND:-
Uncut bricks used: 54
Half bricks used: 12(6 bricks)
Total bricks required: 60
ENGLISH BOND:-
Uncut bricks used: 30
Half bricks used: 54 (27 bricks)
Quater bricks used: 12 (3 bricks)
Total bricks used: 60
http://www.ibstock.com/pdfs/guide-to-good-practice/bwk-good-practice-2001.pdf
Okay, on page 13, for stretcher bond it says you need 60 bricks for a
half brick wall. But, why does it say you need 86 bricks for English
bond with same area? Have I not just proved that you still only need 60
bricks?
Richard
Okay, I just got it.
When you make the English bond, each header uses up one full brick. You
cannot make two headers from one brick. That is how the calculation has
been made out.
So, with a half brick wall, you wast a lot of brick.
With a full brick wall, there will be considerably less waste as you
don't have to cut a brick for the headers, you can just use a full brick.
In my opinion, those quantities ought to be given for a brick wall (not
half brick as they are). Because I would have though no-one constructs a
half brick English bond wall (I imagine).
John Williamson
for "half brick" walls. If it's a half brick wall with the back hidden,
then quite often the headers are just left sticking out of the back.
Eleven inch cavity walls such as were used for houses in the fifties or
for decorative walls now are made from two stretcher bond skins fastened
together with wire ties.
> With a full brick wall, there will be considerably less waste as you
> don't have to cut a brick for the headers, you can just use a full brick.
>
> In my opinion, those quantities ought to be given for a brick wall (not
> half brick as they are). Because I would have though no-one constructs a
> half brick English bond wall (I imagine).
Not from choice, anyway, though the architect or client may specifiy
that that's what they want.
As one poster has said, British brick sizes were designed for feet and
inches, and square yards, with four facers or eight headers per linear
yard, and four courses to the foot. This gives 48 bricks to the square
yard for stretcher bond, half a brick thick, or 96 per square yard of
nominal 9 inch brickwork (any bond), the calculations in the brochure
may have been converted from this just by multiplying by the appropriate
factor of about 1.2. In real life, it's not so easy.
Tabby
wrote:
Work it out for chinese bond and other hollow bridged walls and you
get a different figure again.
NT
harry
>
> > Okay, on page 13, for stretcher bond it says you need 60 bricks for a
> > half brick wall. But, why does it say you need 86 bricks for English
> > bond with same area? Have I not just proved that you still only need 60
> > bricks?
>
> Okay, I just got it.
>
> When you make the English bond, each header uses up one full brick. You
> cannot make two headers from one brick. That is how the calculation has
> been made out.
>
> So, with a half brick wall, you wast a lot of brick.
>
> With a full brick wall, there will be considerably less waste as you
> don't have to cut a brick for the headers, you can just use a full brick.
>
> In my opinion, those quantities ought to be given for a brick wall (not
> half brick as they are). Because I would have though no-one constructs a
>
> - Show quoted text -
How is there headers in a half brick wall? There can only be strechers.
Richard
Yes. Really you would not half a brick, and put it as a header in a
half-brick wall. You would tend to put the whole brick in. My thoughts.
John Williamson
If there's enough room to do that, it's done that way, otherwise, it's a
case of roughly cutting a brick in half. It could be for decorative
effect, and need not be an "official" bond pattern.
harry
wrote:
>
> - Show quoted text -
Well, once you start cutting them, all calculations go out the window.
The only thing I can think of is the closers for corners and ends.
John Williamson
Not entirely, when I was estimating for a living, I used to get pretty
close, and was very rarely more than a few bricks out on our orders. Of
course, it did help that I was the one drawing up the design as well....
Richard
The figure of 86 bricks in Ibstocks Catalogue for a half brick English
bond is accurate. Because if you don't use both half of the brick bats
in the wall, you will need 86 bricks, rather than 60. Seems a waste
though. But, perhaps occationally people do it.